Metastasis and angiogenesis in cervical cancer: key aspects of purinergic signaling in platelets and possible therapeutic targets.

Cervical cancer ranks as the fourth most common and fatal cancer among women worldwide. Studies have demonstrated a strong association between purinergic platelet signaling and tumor progression in this type of cancer. The literature shows that neoplastic cells, when in the bloodstream, secrete adenosine triphosphate (ATP) and adenosine nucleotide diphosphate (ADP) that act on their corresponding platelet P2Y and P2X receptors. The interaction of these nucleotides with their receptors results in platelet activation and degranulation, ensuing several consequences, such as vascular endothelial growth factor (VEGF), platelet-derived growth factor, matrix metalloproteinases, ADP, and ATP. These molecules play essential roles in angiogenesis and tumor metastasis in cervical cancer. Several purinergic receptors are found in endothelial cells. Their activation, especially P2Y2, by the nucleotides released by platelets can induce relaxation of the endothelial barrier and consequent extravasation of tumor cells, promoting the development of metastases. Cancer cells that enter the bloodstream during the metastatic process are also subject to high shear stress and immune surveillance. In this context, activated platelets bind to circulating tumor cells and protect them against shear stress and the host's immune system, especially against natural killer cells, facilitating their spread throughout the body. Furthermore, activation of the P2Y12 receptor present on the platelet surface promotes the release of VEGF, the main inducer of angiogenesis in cervical cancer, in addition to increasing the concentration of several other pro-angiogenic molecules. Therefore, this review will address the role of platelet purinergic signaling in tumor progression of cervical cancer and propose possible therapeutic targets.

The anti-inflammatory effect of resistance training in hypertensive women: the role of purinergic signaling.

BACKGROUND AND METHODS: Essential arterial hypertension triggers a chronic inflammatory process that seems to be linked to purinergic signaling. Physical exercise exhibit anti-inflammatory properties and is able to modulates purinergic system. The aim of this study was to evaluate the effect of 6 months of resistance training on inflammatory markers, purinergic system components, hemodynamic and anthropometric parameters in hypertensive woman. METHODS: A total of 31 hypertensive group and 28 normotensive (control group) middle-aged sedentary women were submitted to 6 months of resistance training. All measurements and blood collection were carried out before (pretest), after 3 months and after 6 months (posttest) of training. Purinergic enzymes [nucleoside triphosphate diphosphohydrolase (NTPDase) and adenosine deaminase] were assessed in lymphocytes; IL-6, IL-10, ATP and C-reactive protein levels were measured in serum. RESULTS: Six months of resistance training was able to significantly reduce blood pressure (BP), IL-6, C-reactive protein, ATP levels as well as NTPDase and adenosine deaminase activities in hypertensive group. Physical training was also able to increase IL-10 levels in hypertensive group. A positive correlation was found between BP, enzyme activities and levels of ATP and IL-6. A negative correlation was found between BP and IL-10. Positive correlation was found between NTPDase and IL-6 levels (P < 0.05) as well as ATP levels and IL-6 levels. CONCLUSION: Our findings demonstrated the relationship between purinergic signaling and inflammation in hypertension and suggests that resistance training serve as tool to reduce inflammation in hypertensive woman by modulating purinergic system.

Exercise with blood flow restriction as a new tool for health improvement in hypertensive elderly women: the role of purinergic enzymes.

BACKGROUND: Purinergic signaling has been considered one of the mechanisms by which exercise exerts its antihypertensive effects; and research on the effects of blow flow restriction (BFR) exercise has increased as an alternative for elderly hypertensive patients. We analyzed the acute responses of NTPDase and adenosine deaminase (ADA) activities to low intensity aerobic exercise (LIAE) with BFR in lymphocytes of hypertensive elderly women. METHODS: Sixteen hypertensive elderly women performed three exercise protocols: LIAE; high intensity aerobic exercise (HIAE) and LIAE+BFR. Blood pressure, heart rate and blood collection were carried out before exercise, immediately after exercise and 30 min after exercise. NTPDase and ADA activities were measured in lymphocytes. RESULTS: Our results showed that LIAE+BFR triggered the same stimuli when compared to HIAE exercise regarding to NTPDases activities, suggesting that both protocols trigger an augment of these enzyme activities in response to: 1) increase in ATP release during exercise; and 2) need of adenosine generation to promotes anti-inflammatory responses in the recovery period. HIAE protocol was more effective than the others to trigger combined hypotensive and anti-inflammatory effects in the recovery period. CONCLUSIONS: This study showed that BFR is a good tool to promote anti-inflammatory effects similar (not equal) to HIAE. Moreover, LIAE+BFR promotes much more stimuli and adaptations related to immune functions than low intensity protocols, bringing more benefits for the hypertensive elderly population.

Involvement of the Cholinergic Parameters and Glial Cells in Learning Delay Induced by Glutaric Acid: Protection by N-Acetylcysteine.

Dysfunction of basal ganglia neurons is a characteristic of glutaric acidemia type I (GA-I), an autosomal recessive inherited neurometabolic disease characterized by deficiency of glutaryl-CoA dehydrogenase (GCDH) and accumulation of glutaric acid (GA). The affected patients present clinical manifestations such as motor dysfunction and memory impairment followed by extensive striatal neurodegeneration. Knowing that there is relevant striatal dysfunction in GA-I, the purpose of the present study was to verify the performance of young rats chronically injected with GA in working and procedural memory test, and whether N-acetylcysteine (NAC) would protect against impairment induced by GA. Rat pups were injected with GA (5 µmol g body weight-1, subcutaneously; twice per day; from the 5th to the 28th day of life) and were supplemented with NAC (150 mg/kg/day; intragastric gavage; for the same period). We found that GA injection caused delay procedural learning; increase of cytokine concentration, oxidative markers, and caspase levels; decrease of antioxidant defenses; and alteration of acetylcholinesterase (AChE) activity. Interestingly, we found an increase in glial cell immunoreactivity and decrease in the immunoreactivity of nuclear factor-erythroid 2-related factor 2 (Nrf2), nicotinic acetylcholine receptor subunit alpha 7 (α7nAChR), and neuronal nuclei (NeuN) in the striatum. Indeed, NAC administration improved the cognitive performance, ROS production, neuroinflammation, and caspase activation induced by GA. NAC did not prevent neuronal death, however protected against alterations induced by GA on Iba-1 and GFAP immunoreactivities and AChE activity. Then, this study suggests possible therapeutic strategies that could help in GA-I treatment and the importance of the striatum in the learning tasks.

Post-thyroidectomy hypothyroidism increases the expression and activity of ectonucleotidases in platelets: Possible involvement of reactive oxygen species.

Signaling mediated by purines is a widespread mechanism of cell-cell communication related to vasomotor responses and the control of platelet function in the vascular system. However, little is known about the involvement of this signaling as well as the role of reactive oxygen species (ROS) in the development of hypothyroidism. Therefore, the present study investigates changes in the purinergic system, including enzyme activities and expression in platelets, and oxidative profiles in patients with post-thyroidectomy hypothyroidism. The nucleoside triphosphate diphosphohydrolase 1 (NTPDase/CD39) expression in patients increased by 40%, and the adenosine triphosphate (ATP) or adenosine diphosphate (ADP) hydrolyzing activity increased by 82% and 70%, respectively. The activities of ecto-5´-nucleotidase and adenosine deaminase (ADA) also significantly enhanced (39% and 52%, respectively), which correlates with a 45% decrease in adenosine concentration. Furthermore, these patients demonstrated an increased production of ROS (42%), thiobarbituric acid reactive substances (TBARS) (115%), carbonyl protein (30%) and a decreased glutathione S-transferase (GST) activity (20%). This study demonstrates that hypothyroidism interferes with adenine nucleoside and nucleotide hydrolysis and this is correlated with oxidative stress, which might be responsible for the increase in ADA activity. This increase causes rapid adenosine deamination, which can generate a decrease in their concentration in the systemic circulation, which can be associated with the development of vascular complications.

Quercetin changes purinergic enzyme activities and oxidative profile in platelets of rats with hypothyroidism.

Diseases related to thyroid hormones have been extensively studied because affect a large number of individuals, and these hormones participate in the regulation of the whole organism homeostasis. However, little is known about the involvement of purinergic signaling related to oxidative stress in hypothyroidism and possible therapeutic adjuncts for treatment of this disorder. Thus, the present study investigates the effects of quercetin on NTPDase, 5'-nucleotidase and adenosine deaminase activities, platelet aggregation and oxidative profile in platelets of rats with methimazole (MMI)-induced hypothyroidism. Methimazole at a concentration of 20mg/100mL was administered for 90days. From the second month the animals received quercetin 10 or 25mg/kg for 60days. Results showed that: Ecto-5'-nucleotidase activity decreased in methimazole/water group and the treatment with quercetin 25mg/kg decreased NTPDase, 5'-nucleotidase and adenosine deaminase activities. Moreover, platelet aggregation increased in methimazole/water group. Lipid peroxidation increased while superoxide dismutase and catalase activities decreased, but, interestingly, the treatment with quercetin reversed these changes. These results demonstrated that quercetin modulates adenine nucleotide hydrolysis decreasing the ADP formation and adenosine deamination. At the same time quercetin improves the oxidative profile, as well as reduces platelet aggregation, which together with the modulation in the nucleotides levels can contribute to the prevention of platelet disorders.

Association between Periodontal Condition and Nutritional Status of Brazilian Adolescents: A Population-based Study.

BACKGROUND: Obesity is a serious problem of public health and affects all socio-economic groups, irrespective of age, sex or ethnicity. The aim of this study was to evaluate the association between periodontal condition and nutritional status of adolescents. METHODS: This was a cross-sectional study using a probability cluster sampling, and the sample was defined by statistical criterion, consisting of 559 students aged 15-19 yr enrolled in public schools of adolescents of Campina Grande, PB, Brazil in 2012. Socioeconomic characteristics were analyzed, as well as self-reported general and oral health, anthropometric data and periodontal condition (CPI and OHI-S). Descriptive and analytical analysis from bivariate and multivariate Poisson regression analysis with 5% significance level was performed. RESULTS: Of the 559 adolescents, 18.6% were overweight and 98.4% had some form of periodontal changes such as: bleeding (34.3%), calculus (38.8%), shallow pocket (22.9%) and deep pocket (2.3%). There was association between presence of periodontal changes with obesity (P<0.05; CI 95%: 0.99 [0.98 - 0.99]). CONCLUSION: The association between presence of periodontal changes and obesity status in adolescents was indicated.

Quercetin protects the impairment of memory and anxiogenic-like behavior in rats exposed to cadmium: Possible involvement of the acetylcholinesterase and Na(+),K(+)-ATPase activities.

The present study investigated the effects of quercetin in the impairment of memory and anxiogenic-like behavior induced by cadmium (Cd) exposure. We also investigated possible alterations in acetylcholinesterase (AChE), Na(+),K(+)-ATPase and δ-aminolevulinate dehydratase (δ-ALA-D) activities as well as in oxidative stress parameters in the CNS. Rats were exposed to Cd (2.5mg/kg) and quercetin (5, 25 or 50mg/kg) by gavage for 45days. Animals were divided into eight groups (n=10-14): saline/control, saline/Querc 5mg/kg, saline/Querc 25mg/kg, saline/Querc 50mg/kg, Cd/ethanol, Cd/Querc 5mg/kg, Cd/Querc 25mg/kg and Cd/Querc 50mg/kg. Results demonstrated that Cd impaired memory has an anxiogenic effect. Quercetin prevented these harmful effects induced by Cd. AChE activity decreased in the cerebral cortex and hippocampus and increased in the hypothalamus of Cd-exposed rats. The Na(+),K(+)-ATPase activity decreased in the cerebral cortex, hippocampus and hypothalamus of Cd-exposed rats. Quercetin prevented these effects in AChE and Na(+),K(+)-ATPase activities. Reactive oxygen species production, thiobarbituric acid reactive substance levels, protein carbonyl content and double-stranded DNA fractions increased in the cerebral cortex, hippocampus and hypothalamus of Cd-exposed rats. Quercetin totally or partially prevents these effects caused by Cd. Total thiols (T-SHs), reduced glutathione (GSH), and reductase glutathione (GR) activities decreased and glutathione S-transferase (GST) activity increased in Cd exposed rats. Co-treatment with quercetin prevented reduction in T-SH, GSH, and GR activities and the rise of GST activity. The present findings show that quercetin prevents alterations in oxidative stress parameters as well as AChE and Na(+),K(+)-ATPase activities, consequently preventing memory impairment and anxiogenic-like behavior displayed by Cd exposure. These results may contribute to a better understanding of the neuroprotective role of quercetin, emphasizing the influence of this flavonoid in the diet for human health, possibly preventing brain injury associated with Cd intoxication.

Dental caries and periodontal disease in Brazilian children and adolescents with cerebral palsy.

The aim of the present study was determine the prevalence and factors associated with dental caries and periodontal disease in Brazilian children and adolescents with cerebral palsy (CP). This is a cross-sectional study conducted with 80 patients ranging in age from 2 to 18 years old. Oral exams were conducted by an examiner with records of DMFT, dmft, Gingival Bleeding Index (GBI) and Community Periodontal Index (CPI). The statistical analysis used Poisson Regression with robust variance estimation (α = 0.05). The prevalence of dental caries was 59.3%, with DMFT and mean dmft of 1.71 ± 2.42 and 2.22 ± 3.23, respectively. The mean GBI was 22.44%, and in the CPI, the prevalence of gingival bleeding, calculus, shallow and deep pockets were 94.73%, 79.62%, 12.90% and 3.22%, respectively. The caregiver's educational level of less than eight years were associated with the dental caries experience (PR = 1.439; 95%CI = 1.09-1.89). The periodontal alterations were associated with female sex (PR = 0.82; 95%CI = 0.69-0.97), caregiver's educational level of less than eight years (PR = 1.15; 95%CI = 1.03-1.29), poor oral perception (PR = 0.89; 95%CI = 0.80-0.98), serious communication problem (PR = 0.87; 95%CI = 0.76-0.99) and athetoid type of CP (PR = 0.85; 95%CI = 0.75-0.97). The patients with CP presented high dental caries experience and periodontal alterations, which were associated with their demographic, socioeconomic, oral health perception and systemic information.

N-acetylcysteine prevents spatial memory impairment induced by chronic early postnatal glutaric acid and lipopolysaccharide in rat pups.

BACKGROUND AND AIMS: Glutaric aciduria type I (GA-I) is characterized by accumulation of glutaric acid (GA) and neurological symptoms, such as cognitive impairment. Although this disease is related to oxidative stress and inflammation, it is not known whether these processes facilitate the memory impairment. Our objective was to investigate the performance of rat pups chronically injected with GA and lipopolysaccharide (LPS) in spatial memory test, antioxidant defenses, cytokines levels, Na+, K+-ATPase activity, and hippocampal volume. We also evaluated the effect of N-acetylcysteine (NAC) on theses markers. METHODS: Rat pups were injected with GA (5 umol g of body weight-1, subcutaneously; twice per day; from 5th to 28th day of life), and were supplemented with NAC (150 mg/kg/day; intragastric gavage; for the same period). LPS (2 mg/kg; E.coli 055 B5) or vehicle (saline 0.9%) was injected intraperitoneally, once per day, from 25th to 28th day of life. Oxidative stress and inflammatory biomarkers as well as hippocampal volume were assessed. RESULTS: GA caused spatial learning deficit in the Barnes maze and LPS potentiated this effect. GA and LPS increased TNF-α and IL-1ß levels. The co-administration of these compounds potentiated the increase of IL-1ß levels but not TNF-α levels in the hippocampus. GA and LPS increased TBARS (thiobarbituric acid-reactive substance) content, reduced antioxidant defenses and inhibited Na+, K+-ATPase activity. GA and LPS co-administration did not have additive effect on oxidative stress markers and Na+, K+ pump. The hippocampal volume did not change after GA or LPS administration. NAC protected against impairment of spatial learning and increase of cytokines levels. NAC Also protected against inhibition of Na+,K+-ATPase activity and oxidative markers. CONCLUSIONS: These results suggest that inflammatory and oxidative markers may underlie at least in part of the neuropathology of GA-I in this model. Thus, NAC could represent a possible adjuvant therapy in treatment of children with GA-I.

Moderate red wine and grape juice consumption modulates the hydrolysis of the adenine nucleotides and decreases platelet aggregation in streptozotocin-induced diabetic rats.

This study investigated the ex vivo effects of the moderate red wine (RW) and grape juice (GJ) consumption, and the in vitro effects of the resveratrol, caffeic acid, gallic acid, quercetin, and rutin on NTPDase (nucleoside triphosphate diphosphohydrolase), ecto-nucleotide pyrophosphatase/phosphodiesterase (E-NPP), 5'-nucleotidase, and adenosine deaminase (ADA) activities in platelets and platelet aggregation from streptozotocin-induced diabetic rats. The animals were divided into six groups (n = 10): control/saline, control/GJ, control/RW, diabetic/saline, diabetic/GJ, and diabetic/RW. RW and GJ were administered for 45 days; after this period, the blood was collected for experimental determinations. Results showed that NTPDase, E-NPP, 5'-nucleotidase, and ADA activities as well as platelet aggregation were increased in the diabetic/saline group compared to the control/saline group. Treatment with RW and GJ increased ectonucleotidases activities and prevented the increase in the ADA activity in the diabetic/GJ and diabetic/RW groups. Platelet aggregation was also decreased by the treatment with RW and GJ in the diabetic/GJ and diabetic/RW groups. In the in vitro tests, resveratrol, caffeic acid, and gallic acid increased ATP, ADP, and AMP hydrolysis, while quercetin and rutin decreased the hydrolysis of these nucleotides in platelets of diabetic rats. The ADA activity and platelet aggregation were reduced in platelets of diabetic rats in the presence of all polyphenols tested in vitro. These findings suggest that RW, GJ, and all polyphenols tested were able to modulate the ectoenzymes activities. Moreover, a decrease in the platelet aggregation was observed and it could contribute to the prevention of platelet abnormality, and consequently vascular complications in diabetic state.