Effects of calcium supplementation on changes in the IL2, IL4, IL6, IL10 axes and oxidative stress in pregnant women at risk for pre-eclampsia.

BACKGROUND: Pregnant women with hypertensive disorders are at increased risk for inflammatory diseases and oxidative stress. The dilemma raised by the best dosage of calcium supplementation on these factors is evident. The aim of the current study was to examine the effects of calcium on biomarkers of the purinergic system, inflammation and oxidative stress, which are factors contributing to vascular damage in pregnant women at high risk of pre-eclampsia. METHODS: A prospective, double-blind and placebo-controlled study conducted with 101 women at risk of pre-eclampsia were randomized to take 500 mg calcium/day or 1,500 mg calcium/day or placebo for 6 weeks from the 20th gestational week until delivery. Fasting blood samples were collected at the beginning of the study and 6 weeks after the intervention. RESULTS: Taking calcium supplements (500 mg calcium/day) led to a significant increase in ATP hydrolysis (p < 0.05), NTPDase activity with increased hydrolysis of ADP and AMP nucleotides in platelets and lymphocytes. In the intragroup analysis IL-2, IL-6, IL-4 and interferon-É£ presented lower values in the calcium 1,500 mg/day group (p < 0.005). Oxidative stress was assessed by TBARS pro-oxidant marker, with an increase for the calcium groups when compared to the placebo group. The Vitamin C antioxidant marker presented a significant increase (p < 0.005) for the group that received high calcium doses. CONCLUSIONS: Calcium administration for 6 weeks had antioxidant action and positively modulated the purinergic system and inflammatory markers in pregnant women at risk of pre-eclampsia.

Evaluation of the effects of metformin on antioxidant biomarkers and mineral levels in patients with type II diabetes mellitus: A cross-sectional study.

Diabetes mellitus (DM) and arterial hypertension are considered serious public health problems. Several studies have shown that oxidative stress is usually related to the onset of DM and hypertension, as well their associated complications. Moreover, the levels of some minerals are closely related to the pathophysiology of these diseases. Thus, in this study we aimed to evaluate the effect of metformin on the redox profile and mineral levels in the serum of patients with DM type 2 and hypertension. We also tested the effect of metformin on the viability and redox profile of peripheral blood mononuclear cells (PBMCs) for 24 h. As expected, we found that patients with type 2 DM and hypertension + type 2 DM had higher fasting glucose and triglyceride levels. As groundbreaking research, we found that both patients DM type 2 and Hypertension + DM type 2 had reduced myeloperoxidase (MPO) activity. On the other hand, the levels of total thiols (PSH) and vitamin C were increased. There was no statistical significance for the alterations in mineral levels. In addition, metformin treatment had no cytotoxic effect on PBMCs. Similarly, in patients of both groups, MPO activity was reduced and PSH levels were increased in PBMCs. We have shown that metformin is a drug with a protective effect in patients with DM type 2 against oxidative stress by reducing MPO activity and improving the levels of PSH and antioxidant defenders such as vitamin C. The results of in vitro assays support the antioxidant effect of metformin. Furthermore, we suggest studies to assess the biochemical mechanisms of metformin and how it can be used in a pharmacological therapeutic perspective against oxidative damage.

The signaling effects of ATP on melanoma-like skin cancer.

Melanoma is a type of skin cancer originated by the malignant transformation of melanocytes. Increasing incidence and mortality require efforts focused on studies and research about this cancer. Its microenvironment is rich in extracellular ATP, but there are no studies evaluating the ectonucleotidases and ATP effects on tumor-derived melanoma cells with known amounts of ATP. This way, the objective of this work was to evaluate the purinergic signaling in the pathophysiology of in vivo melanoma and the in vitro effects of ATP signaling. We found increased and effective extracellular ATP hydrolysis in platelets and a significant decrease of extracellular ATP levels and adenosine hydrolysis. In addition, we cultured PBMCs of melanoma patients and used ATP salt with specific concentrations to evaluate its signaling effects. The enzymatic activity analysis revealed that even with higher ATP doses cells metabolize adenine nucleotides less efficiently, and present low ATP, ADP and AMP hydrolytic activity in CM compared to CT cells. In summary, we showed for the first time important data about the purinergic signaling in the pathophysiology of melanoma and ATP signaling exercising immunosuppressive effects. Therefore, as already shown for other tumors, the purinergic signaling should be considered a potential target for melanoma management and treatment and could offer novel therapeutic prospects.

1α, 25-Dihydroxyvitamin D3 alters ectonucleotidase expression and activity in human cutaneous melanoma cells.

PURPOSE: We hypothesized that vitamin D decreases rates of adenosine formation in human cutaneous melanoma cells through the inhibition of extracellular adenosine 5'-triphosphate breakdown, thereby affecting tumor cell viability. Therefore, the objective of this study was to explore the mechanisms of action of 1α, 25-dihydroxyvitamin D3 (1,25(OH)2 D3) on the activity and expression of ectonucleotidases in cutaneous melanoma cells. METHODS: A human melanoma cell line, SK-Mel-28, was treated with 1 to 50 nM of the active vitamin D metabolite (1,25(OH)2 D3) over 24 hours, followed by determination of NTPDase1/CD39 and ecto-5'-nucleotidase/CD73 activity and expression rates of the purinergic system-related NTPDASE1, NT5E and adenosine deaminase and vitamin D receptor. An 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay was used to evaluate cellular viability. RESULTS: 1,25(OH)2 D3 decreased adenosine monophosphate hydrolysis via ecto-5'-nucleotidase/CD73 and expression of CD73, but did not change NTPDase1/CD39 activity; it increased the CD39 expression. We also observed an increase of cell viability at 1 nM, but this viability decreased as the concentrations of vitamin D active metabolite increased to 50 nM. There were no differences in gene expression levels. CONCLUSION: To the best of our knowledge, we showed for the first time a mechanism of control of adenosine production via modulation of the purinergic system in cutaneous melanoma cells treated with the active metabolite of vitamin D. This study provides original information regarding mechanisms, in which vitamin D plays a key role in preventing tumor progression in human melanoma cells.

High-intensity intermittent exercise increases adenosine hydrolysis in platelets and lymphocytes and promotes platelet aggregation in futsal athletes.

Acute bouts of high-intensity intermittent exercise (HIIE) or sports are associated with changes in lymphocytes and platelet functions and we hypothesized that the purinergic system is involved with these alterations. We investigated the activity of ectonucleotidases in platelets and lymphocytes as well as the platelet aggregation of futsal players in response to an acute protocol of HIIE. Thus, 19 male semi-professional futsal players were submitted to 40 min of HIIE on a treadmill. Blood samples were collected three-time points: before exercise, immediately after, and 30 min after the end of the session. Platelet-rich plasma (PRP) and lymphocytes were isolated. ATP, ADP, AMP, and adenosine hydrolysis, NTPDase1 (CD39) expression as well as platelet aggregation were measured. Our results showed HIIE induced a decrease in ATP and ADP hydrolysis in platelets, an increase in adenosine hydrolysis and an increase in platelet aggregation immediately after exercise. After 30 min of recovery, enzymatic activity and platelet aggregation returned to baseline levels. In lymphocytes, adenosine hydrolysis was augmented immediately after exercise and remained increased even after 30 min of recovery. In conclusion, acute HIIE triggers a transient proaggregant status that is reverted after a 30 min of recovery. The effects of HIIE in lymphocytes remained after 30 min of recovery, indicating a pro-inflammatory response. This work elucidated some of the mechanisms by which purinergic system regulates lymphocytes and platelets activities related to HIIE, suggesting that the type of exercise may influence an increase in platelet aggregation even in trained individuals.