Vitamin D levels reverberate in monocytes modulation in hemodialysis patients

BACKGROUND

Patients with chronic kidney disease (CKD) have a severe vitamin D deficiency and increasing epidemiological data suggesting that this deficiency may play a role in overall morbidity and mortality associated with CKD. It is known that vitamin D regulates the immune system, however, in dialysis patients this deficiency and the modulation of proinflammatory cells is unclear. Among these, monocytes arouse interest considering they constitutively express vitamin D receptors.

AIM

This study aimed the evaluation of monocytic profile in CKD patients according to vitamin D levels.

METHODS

Patients in hemodialysis (HD) were divided into two groups, regarding vitamin D levels: Group 1, vitamin D <26 ng/ml (n = 15) and Group 2, vitamin D ≥26 ng/ml (n = 18). Whole blood was collected aiming evaluation of (a) monocytic populations through CD14 and CD16 expression, (b) reactive oxygen species (ROS) generation, and (c) apoptosis.

RESULTS

We observed that in Group 1, when compared to Group 2, there was a significant increase in intermediate monocytes (CD14⁺⁺ CD16 ⁺ ; 34.7 ± 31.6 vs. 12.1 ± 6.3; p = 0.006, respectively) and decrease in classical ones (CD14 ⁺⁺ CD16 ^- ; 45.3 ± 31.8 vs. 70.4 ± 25.1; p = 0.017, respectively). There was no difference between groups regarding nonclassical monocytes (CD14 ⁺ CD16 ⁺⁺ ), as well as to apoptosis and to ROS generation.

CONCLUSION

This study suggests that HD patients with lower vitamin D levels might have an intensified inflammatory outline as intermediate monocytes with an inflammatory pattern are increased in this population, when compared with patients with higher levels of vitamin D.

The lectin BJcuL induces apoptosis through TRAIL expression, caspase cascade activation and mitochondrial membrane permeability in a human colon adenocarcinoma cell line

It has been demonstrated that the cytotoxic effect of BJcuL, the lectin isolated from Bothrops jararacussu venom, on human gastric carcinoma is accompanied by the inhibition of extracellular matrix adhesion, cytoskeleton disassembly and apoptosis induction. The present study aimed to evaluate the apoptosis mechanisms triggered by the BJcuL interaction with specific glycans on the surface of HT29 human colon adenocarcinoma cells. The results demonstrated that BJcuL interacts with glycoligands targets on the cell, which were inhibited in the presence of d-galactose. It shows a dose-dependently cytotoxic effect that is inhibited in the presence of d-galactose. A dose-dependent cell aggregation decrease was also observed for the HT29 cells. Analysis of cell proliferation inhibition was assessed by anti-PCNA and demonstrated that lectin diminishes PCNA expression when compared with untreated cells. Differences in apoptotic marker expression estimated by immunohistochemistry revealed that the lectin promotes an increase in TRAIL expression, leading to an increase in the expression of FADD, caspase-8 and Bax. Besides the increased expression of apoptosis-related proteins, our results revealed that the lectin promotes a mitochondrial respiration decrease and a 75% increase in the amount of cytochrome c released. Together these results suggest that the cytotoxicity of BJcuL can sensitize pro-apoptotic proteins in the cytoplasm and mitochondria, leading to the apoptotic cascade.