Differential roles of cyclooxygenase enzymes in the regulation of murine juvenile undifferentiated spermatogonia.

BACKGROUND: Acetaminophen and ibuprofen are widely administered to babies due to their presumed safety as over-the-counter drugs. However, no reports exist on the effects of cyclooxygenase inhibitors on undifferentiated spermatogonia and spermatogonial stem cells. Infancy represents a critical period for spermatogonial stem cell formation and disrupting spermatogonial stem cells or their precursors may be associated with infertility and testicular cancer formation. OBJECTIVES: The goal of this study was to examine the molecular and functional impact of cyclooxygenase inhibition and silencing on early steps of undifferentiated spermatogonia (u spg) and spermatogonial stem cell development, to assess the potential reproductive risk of pharmaceutical cyclooxygenase inhibitors. METHODS: The effects of cyclooxygenase inhibition were assessed using the mouse C18-4 undifferentiated juvenile spermatogonial cell line model, previously shown to include cells with spermatogonial stem cell features, by measuring prostaglandins, cell proliferation, and differentiation, using cyclooxygenase 1- and cyclooxygenase 2-selective inhibitors NS398, celecoxib, and FR122047, acetaminophen, and ibuprofen. Cyclooxygenase 1 gene silencing was achieved using a stable short-hairpin RNA approach and clone selection, then assessing gene and protein expression in RNA sequencing, quantitative real-time polymerase chain reaction, and immunofluorescence studies. RESULTS: Cyclooxygenase 2 inhibitors NS398 and celecoxib, as well as acetaminophen, but not ibuprofen, dose-dependently decreased retinoic acid-induced expression of the spg differentiation gene Stra8, while NS398 decreased the spg differentiation marker Kit, suggesting that cyclooxygenase 2 is positively associated with spg differentiation. In contrast, short-hairpin RNA-based cyclooxygenase 1 silencing in C18-4 cells altered cellular morphology and upregulated Stra8 and Kit, implying that cyclooxygenase 1 prevented spg differentiation. Furthermore, RNA sequencing analysis of cyclooxygenase 1 knockdown cells indicated the activation of several signaling pathways including the TGFb, Wnt, and Notch pathways, compared to control C18-4 cells. Notch pathway genes were upregulated by selective cyclooxygenase inhibitors, acetaminophen and ibuprofen. CONCLUSION: We report that cyclooxygenase 1 and 2 differentially regulate undifferentiated spermatogonia/spermatogonial stem cell differentiation. Cyclooxygenases regulate Notch3 expression, with the Notch pathway targeted by PGD2. These data suggest an interaction between the eicosanoid and Notch signaling pathways that may be critical for the development of spermatogonial stem cells and subsequent spermatogenesis, cautioning about using cyclooxygenase inhibitors in infants.

EVI1 upregulates PTGS1 (COX1) and decreases the action of tyrosine kinase inhibitors (TKIs) in chronic myeloid leukemia cells.

Tyrosine kinase inhibitors (TKIs) are highly effective in treating chronic myelogenous leukemia (CML). However, primary and acquired drug resistance to TKIs have been reported. In this study, we used RNA sequencing followed by RQ-PCR to show that the proto-oncogene EVI1 targets the drug-metabolizing gene PTGS1 in CML. The PTGS1 promoter element had an EVI1 binding site, and CHIP assay confirmed its presence. Data from a publicly available CML microarray dataset and an independent set of CML samples showed a significant positive correlation between EVI1 and PTGS1 expression in CML. Downregulation of EVI1 in K562 cells and subsequent treatment with TKIs resulted in a lower IC50 in the control cells. Furthermore, combined inhibition of BCR-ABL with imatinib and PTGS1 with FR122047 (PTGS1 inhibitor) synergistically reduced the viability of imatinib-resistant K562 cells. We conclude that elevated EVI1 expression contributes to TKIs resistance and that combined inhibition of PTGS1 and BCR-ABL may represent a novel therapeutic approach.

Mecanismo de los AINES y antiinflamatorios derivados para el control del dolor y la inflamación. Uso de antiinflamatorios en odontología / Mechanism of NSAIDs and derived drugs for pain and inflammation control. Use of anti-inflammatories in odontology

Las urgencias odontológicas son, quizá, las razones principales de atención en el consultorio, muchas veces el significado de dolor se encuentra acompañado por inflamación; el uso de antiinflamatorios no esteroideos (AINES) es común en el ejercicio de la odontología por la excelente respuesta analgésica y antiinflamatoria que tiene, por lo que es importante conocer la fisiopatología de la inflamación y el dolor y cómo actúan los AINES, ya que algunos de estos fármacos tienen respuestas adversas y sitios de acción importantes. Los factores de riesgo por inflamación y dolor nos obligan a conocer la variedad de fármacos que no entran en la clasificación de AINES y que tenemos a disposición, hay más opciones para la elección ante la presencia de inflamación por un factor en particular, cada uno de éstos tienen indicaciones y contraindicaciones que conoceremos, lo cual nos ampliará el conocimiento para dar una prescripción ante la presencia de eventos inflamatorios. Se realizó un estudio detallado de artículos bibliográficos de cada tema, los fármacos más usados en odontología son los AINES, hay poco uso y conocimiento de antiinflamatorios que podemos usar en urgencias, el porcentaje de uso de los AINES derivados del ácido propiónico es alto por la excelente respuesta en pacientes y otras veces por el desconocimiento de más opciones (AU)

Dental emergencies are perhaps the main reasons for care in the office, many times the meaning of pain is accompanied by inflammation, the use of non-steroidal anti-inflammatory drugs is common in the practice of dentistry due to the excellent analgesic and anti-inflammatory response it has, important is knowing the pathophysiology of inflammation and pain, how NSAIDs act, some of these drugs have adverse responses and important sites of action, risk factors for inflammation and pain require us to know the variety of drugs that do not enter the classification of NSAIDs and we have at our disposal, there are more options for choosing in the presence of inflammation due to a particular factor, each of these have indications and contraindications that we will know, it expands our knowledge to give a prescription in the presence of inflammatory events. A detailed study of bibliographic articles on each topic was carried out, the drugs most used in dentistry are NSAIDs, there is little use and knowledge of anti-inflammatories that we can use in the emergency room, the percentage of use of NSAIDs derived from propionic acid is high, due to the excellent response in patients and others due to lack of knowledge of more options (AU)

A Tumor Mitochondria Vaccine Protects against Experimental Renal Cell Carcinoma.

Mitochondria provide energy for cells via oxidative phosphorylation. Reactive oxygen species, a byproduct of this mitochondrial respiration, can damage mitochondrial DNA (mtDNA), and somatic mtDNA mutations have been found in all colorectal, ovarian, breast, urinary bladder, kidney, lung, and pancreatic tumors studied. The resulting altered mitochondrial proteins or tumor-associated mitochondrial Ags (TAMAs) are potentially immunogenic, suggesting that they may be targetable Ags for cancer immunotherapy. In this article, we show that the RENCA tumor cell line harbors TAMAs that can drive an antitumor immune response. We generated a cellular tumor vaccine by pulsing dendritic cells with enriched mitochondrial proteins from RENCA cells. Our dendritic cell-based RENCA mitochondrial lysate vaccine elicited a cytotoxic T cell response in vivo and conferred durable protection against challenge with RENCA cells when used in a prophylactic or therapeutic setting. By sequencing mtDNA from RENCA cells, we identified two mutated molecules: COX1 and ND5. Peptide vaccines generated from mitochondrial-encoded COX1 but not from ND5 had therapeutic properties similar to RENCA mitochondrial protein preparation. Thus, TAMAs can elicit effective antitumor immune responses, potentially providing a new immunotherapeutic strategy to treat cancer.

Cyclooxygenase product inhibition with acetylsalicylic acid slows disease progression in the Han:SPRD-Cy rat model of polycystic kidney disease.

Renal cyclooxygenase (COX) derived eicosanoids are elevated and lipoxygenase (LOX) products are reduced in the Han:SPRD-Cy rat model of polycystic kidney disease (PKD). Selective COX2 inhibition reduces kidney disease progression, but COX1 levels also are elevated in this model. Since the effect of reducing the products of both COX isoforms and the role of LOX products is not known, weanling normal and diseased Han:SPRD-cy littermates were given either low dose acetylsalicylic acid (ASA), nordihydroguaiaretic (NDGA) or no treatment for eight weeks. Renal eicosanoids were altered in the diseased compared to normal cortex, with COX products being higher and LOX products being lower. ASA reduced COX products, cyst growth and kidney water content, while NDGA reduced LOX products without altering disease progression or kidney function. Hence, a human equivalent ASA dose equal to less than one regular strength aspirin per day slowed disease progression, while further reduction of LOX products did not worsen disease progression.

Antipyretic and antioxidant activities of 5-trifluoromethyl-4,5-dihydro-1H-pyrazoles in rats.

The objective of this study was to determine the effect of eight 5-hydroxy-5-trifluoromethyl-4,5-dihydro-1H-1-carboxyamidepyrazoles (TFDPs) on rat body temperature and baker's yeast-induced fever. TFDPs or vehicle (5% Tween 80 in 0.9% NaCl, 5 mL/kg) were injected subcutaneously and rectal temperature was measured as a function of time in 28-day-old male Wistar rats (N = 5-12 per group). Antipyretic activity was determined in feverish animals injected with baker's yeast (Saccharomyces cerevisiae suspension, 0.135 mg/kg, 10 mL/kg, ip). 3-Ethyl- and 3-propyl-TFDP (140 and 200 µmol/kg, respectively, 4 h after yeast injection) attenuated baker's yeast-induced fever by 61 and 82%, respectively. These two effective antipyretics were selected for subsequent analysis of putative mechanisms of action. We then determined the effects on cyclooxygenase-1 and -2 (COX-1 and COX-2) activities on 1,1-diphenyl-2-picrylhydrazyl (DPPH) oxidation in vitro, on tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) levels and on leukocyte counts in the washes of peritoneal cavities of rats injected with baker's yeast. While 3-ethyl- and 3-propyl-TFDP did not reduce baker's yeast-induced increases of IL-1ß or TNF-α levels, 3-ethyl-TFDP caused a 42% reduction in peritoneal leukocyte count. 3-Ethyl- and 3-propyl-TFDP did not alter COX-1 or COX-2 activities in vitro, but presented antioxidant activity in the DPPH assay with an IC50 of 39 mM (25-62) and 163 mM (136-196), respectively. The data indicate that mechanisms of action of these two novel antipyretic pyrazole derivatives do not involve the classic inhibition of the COX pathway or pyrogenic cytokine release.

Treatment with paracetamol, ketorolac or etoricoxib did not hinder alveolar bone healing: a histometric study in rats

Prostaglandins control osteoblastic and osteoclastic function under physiological or pathological conditions and are important modulators of the bone healing process. The non-steroidal anti-inflammatory drugs (NSAIDs) inhibit cyclooxygenase (COX) activity and consequently prostaglandins synthesis. Experimental and clinical evidence has indicated a risk for reparative bone formation related to the use of non-selective (COX-1 and COX-2) and COX-2 selective NSAIDs. Ketorolac is a non-selective NSAID which, at low doses, has a preferential COX-1 inhibitory effect and etoricoxib is a new selective COX-2 inhibitor. Although literature data have suggested that ketorolac can interfere negatively with long bone fracture healing, there seems to be no study associating etoricoxib with reparative bone formation. Paracetamol/acetaminophen, one of the first choices for pain control in clinical dentistry, has been considered a weak anti-inflammatory drug, although supposedly capable of inhibiting COX-2 activity in inflammatory sites. OBJECTIVE: The purpose of the present study was to investigate whether paracetamol, ketorolac and etoricoxib can hinder alveolar bone formation, taking the filling of rat extraction socket with newly formed bone as experimental model. MATERIAL AND METHODS: The degree of new bone formation inside the alveolar socket was estimated two weeks after tooth extraction by a differential point-counting method, using an optical microscopy with a digital camera for image capture and histometry software. Differences between groups were analyzed by ANOVA after confirming a normal distribution of sample data. RESULTS AND CONCLUSIONS: Histometric results confirmed that none of the tested drugs had a detrimental effect in the volume fraction of bone trabeculae formed inside the alveolar socket.

Antipyretic and antioxidant activities of 5-trifluoromethyl-4,5-dihydro-1H-pyrazoles in rats

The objective of this study was to determine the effect of eight 5-hydroxy-5-trifluoromethyl-4,5-dihydro-1H-1-carboxyamidepyrazoles (TFDPs) on rat body temperature and baker’s yeast-induced fever. TFDPs or vehicle (5 percent Tween 80 in 0.9 percent NaCl, 5 mL/kg) were injected subcutaneously and rectal temperature was measured as a function of time in 28-day-old male Wistar rats (N = 5-12 per group). Antipyretic activity was determined in feverish animals injected with baker’s yeast (Saccharomyces cerevisiae suspension, 0.135 mg/kg, 10 mL/kg, ip). 3-Ethyl- and 3-propyl-TFDP (140 and 200 μmol/kg, respectively, 4 h after yeast injection) attenuated baker’s yeast-induced fever by 61 and 82 percent, respectively. These two effective antipyretics were selected for subsequent analysis of putative mechanisms of action. We then determined the effects on cyclooxygenase-1 and -2 (COX-1 and COX-2) activities on 1,1-diphenyl-2-picrylhydrazyl (DPPH) oxidation in vitro, on tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) levels and on leukocyte counts in the washes of peritoneal cavities of rats injected with baker’s yeast. While 3-ethyl- and 3-propyl-TFDP did not reduce baker’s yeast-induced increases of IL-1β or TNF-α levels, 3-ethyl-TFDP caused a 42 percent reduction in peritoneal leukocyte count. 3-Ethyl- and 3-propyl-TFDP did not alter COX-1 or COX-2 activities in vitro, but presented antioxidant activity in the DPPH assay with an IC50 of 39 mM (25-62) and 163 mM (136-196), respectively. The data indicate that mechanisms of action of these two novel antipyretic pyrazole derivatives do not involve the classic inhibition of the COX pathway or pyrogenic cytokine release.

Involvement of endogenous prostaglandin E2 in tubular epithelial regeneration through inhibition of apoptosis and epithelial-mesenchymal transition in cisplatin-induced rat renal lesions.

In the kidney, prostaglandin (PG) E2 is the main PG, playing important roles in maintaining homeostasis or development of pathological settings. Roles of PGE2 in renal lesions remain to be clarified. The expression patterns of PGE2 synthesis enzymes such as cyclooxygenase (COX)-1, COX-2 and microsomal PGE synthase (mPGES)-1, and PGE2 receptors (EP2 and EP4) were examined in cisplatin-induced rat renal failure. The immunoexpressions for COX-1, mPGES-1 and EP4 receptor were increased exclusively in the affected renal tubules, but those of COX-2 and EP2 receptor were not detected; increased expression of COX-1 was confirmed at mRNA level. Using rat renal epithelial cell line (NRK-52E), the effects of PGE2 on cell proliferation were investigated. The addition of PGE2 or 11-deoxy-PGE1 (EP4 receptor agonist) to NRK-52E increased the cell number, indicating the effects of PGE2 via EP4 receptor. Furthermore, 11-deoxy-PGE1-treated NRK-52E cells underwent the G0/G1 arrest and decreased apoptosis. NRK-52E treated with transforming growth factor (TGF)-beta1, an inducer of epithelial-mesenchymal transition (EMT), in the presence of 11-deoxy-PGE1 decreased the mRNA expression of alpha-smooth muscle actin (a marker of myofibroblasts). Collectively, the present study shows that COX-1 plays more important roles than dose COX-2 in cisplatin-induced rat renal failure; the product, PGE2, may regulate renal epithelial regeneration via EP4 receptor through inhibition of apoptosis and EMT.

Pro-ulcer effects of resveratrol in mice with indomethacin-induced gastric ulcers are reversed by L-arginine.

BACKGROUND AND PURPOSE: Although resveratrol is currently being evaluated in pre-clinical studies as a potential cancer chemopreventive agent and cardiovascular stress-releasing compound, treatment with resveratrol severely delays healing of pre-existing gastric ulcers. Resveratrol treatment can also induce endothelial NOS (eNOS) expression. Here, we have attempted to modulate NO production via eNOS in order to alleviate the pro-ulcer effects of resveratrol. EXPERIMENTAL APPROACH: Gastric ulcers were induced in mice with a single dose of indomethacin. The effects of pretreatment with l-arginine on the pro-ulcer effects of resveratrol in these mice were then assessed. We measured ulcer damage scores (DS), myeloperoxidase (MPO) activity, generation of prostaglandin E(2) (PGE(2)) and NO, along with a gene expression study. KEY RESULTS: Resveratrol significantly aggravated damage from indomethacin-induced gastric ulcers, and delayed healing, as shown by increased DS and MPO activity. The mRNA for cyclooxygenase (COX)-1, but not that for COX-2, was inhibited by resveratrol treatment, with reduced synthesis of PGE(2) by gastric tissue. However, resveratrol treatment induced eNOS gene expression and shifted the eNOS/iNOS balance. l-Arginine given before resveratrol in mice with indomethacin-induced ulcers significantly increased tissue NO synthesis and improved ulcer healing. CONCLUSIONS AND IMPLICATIONS: Exogenous l-arginine increased NO formation via raised levels of eNOS induced by resveratrol and protected against the pro-ulcer effects of resveratrol. Therefore, l-arginine might be useful for alleviation of the pro-ulcer side effects of resveratrol in patients.

Sex differences in platelet reactivity and response to low-dose aspirin therapy.

CONTEXT: Recent randomized trials suggest that women may not accrue the same cardioprotective benefits as men do from low-dose aspirin therapy used in primary prevention. Failure of aspirin to suppress platelet aggregation in women is one hypothesized mechanism. OBJECTIVE: To examine differential platelet reactivity to low-dose aspirin therapy by sex. DESIGN, SETTING, AND PARTICIPANTS: A clinical trial of aspirin at 81 mg/d for 14 days was conducted in 571 men and 711 women. Baseline and post-aspirin therapy measures included platelet aggregation to arachidonic acid, adenosine diphosphate, epinephrine, and platelet function analyzer closure time. MAIN OUTCOME MEASURE: Sex differences in cyclooxygenase 1 (COX-1) direct and indirect platelet activation pathways before and after administration of aspirin. RESULTS: In 10 of the 12 platelet agonist exposures, women's platelets were significantly more reactive at baseline. However, after aspirin therapy, the percent aggregation to arachidonic acid (the direct COX-1 pathway) decreased more in women than in men (P<.001) and demonstrated near total suppression of residual platelet reactivity in both men and women. In COX-1 indirect pathways, women experienced the same or more platelet inhibition than men in 8 of the 9 assays yet retained modestly greater platelet reactivity after aspirin therapy. In multivariable analysis, female sex significantly predicted aggregation to 2 muM and 10 muM of adenosine diphosphate (P = .02 and <.001, respectively) and collagen at 5 mug/mL (P<.001) independent of risk factors, age, race, menopausal status, and hormone therapy. CONCLUSIONS: Women experienced the same or greater decreases in platelet reactivity after aspirin therapy, retaining modestly more platelet reactivity compared with men. However, most women achieved total suppression of aggregation in the direct COX-1 pathway, the putative mechanism for aspirin's cardioprotection.