Cholecalciferol Supplementation Did Not Change Interleukin-7 and B cell-Activating Factor Levels and CD95 Expression in B lymphocytes in Patients on Dialysis: A Randomized Pilot-Controlled Trial.

BACKGROUND: End-stage renal disease results in B cell lymphopenia and low levels of vitamin D. Since the link between vitamin D deficiency and B lymphocytes dysfunction are not clear in patients with end-stage renal disease, we suggest that vitamin D adequacy and factors related to the homeostasis of these cells should be investigated. B lymphocytes homeostasis is a process mainly regulated signals of grown and death as interleukin (IL)-7, B cell-activating factor (BAFF)/BAFF-receptor and CD95 expression. OBJECTIVE: As vitamin D serum levels were reduced in patients with end stage renal disease and it is associated with human B homeostasis, we evaluated the effect of cholecalciferol supplementation on dialysis. DESIGN: Randomized, double blind clinical trial in dialysis patients with 25OH Vitamin D deficiency for a period of 12 weeks. MAIN OUTCOME MEASURE: In a pilot study, we investigated the effect of cholecalciferol supplementation (100,000 UI once per week or placebo. In vitro, peripheral blood mononuclear cells isolated by Ficoll-Hypaque centrifugation from 12 healthy volunteers were incubated with healthy or uremic serum in the presence or absence of 25 (OH)DC with 5% CO. RESULTS: There was an increase in the serum 25(OH)D level in the cholecalciferol group. No differences were found in BAFF and IL7 levels and CD95 and BAFF-R expression in B lymphocytes from patients on dialysis after cholecalciferol supplementation. Uremic serum induced an increase in the IL-7, BAFF, BAFF-R and CD95 expression compared with the control. However, we observed no effect of incubation of 25(OH)D3 and 1,25(OH)2D3 on the expression of IL-7, BAFF, BAFF-R and CD95 when incubated in the presence of normal or uremic serum. CONCLUSION: Our results suggest that vitamin D is not involved in mechanisms of regulation of differentiation and survival in B lymphocytes. In conclusion, further studies are needed to explore the effects of vitamin D on B lymphocytes to better evaluate the possible impact of vitamin D on humoral response in the CKD population.

Photobiomodulation modulates the resolution of inflammation during acute lung injury induced by sepsis.

Sepsis is a big health problem and one of the most common causes of acute lung injury (ALI) leading to high mortality. Pro-resolving mediators play an important role in abrogating the inflammation and promoting tissue homeostasis restoration. ALI treatment is still a clinical health problem, so new therapies are needed. Here, we evaluated the effect of photobiomodulation treatment on the resolution process of ALI induced by lipopolysaccharide (LPS). Male Balb/c mice were submitted to LPS (ip) or vehicle and irradiated or not with light emitting diode (LED) 2 and 6 h after LPS or vehicle injection, and the parameters were investigated 3 and 7 days after the injections. Our results showed that after 3 days of LED treatment the blood and bronchoalveolar lavage (BAL) cells as well as interleukins (IL) including IL-6 and IL-17 were reduced. No differences were observed in the bone marrow cells, tracheal reactivity, and lipoxin A4 and resolvin E2. Indeed, after 7 days of LED treatment the bone marrow cells, lymphocytes, and lipoxin A4 were increased, while IL-6, IL-17, and IL-10 were decreased. No differences were observed in the blood cells and tracheal reactivity. Thus, our results showed that LED treatment attenuated ALI induced by sepsis by modulating the cell mobilization from their reserve compartments. In addition, we also showed later effects of the LED up to 7 days after the treatment. This study proposes photobiomodulation as therapeutic adjuvant to treat ALI.

Flow Cytometry of CD14, VDR, Cyp27 and Cyp24 and TLR4 in U937 Cells.

Chronic Kidney Disease (CKD) patients present a micro inflammation state due to failure renal function. The calcitriol has been described as an anti-inflammatory factor that might modulates the inflammatory response in CKD patients. However, these patients have deficiency of Calcitriol due to failure renal function. But, synthesis of this vitamin has been reported in extra renal production, as in monocytes. In this context, it has been reported that the supplementation with 25 vitamin D (calcidiol or inactive form of vitamin D) induces monocytes to downregulate inflammation, due to the intracellular 1α-hidroxilase that converts calcidiol to calcitriol in these cells. Besides some reports used RT-qPCR, Western Blot or immunofluorescence techniques to investigate the expression of inflammatory and vitamin D machinery biomarkers in several disease, in the present study we used flow cytometry technique to evaluate the effect of 25 vitamin D on CD14, Toll-like receptor 4 (TLR4), vitamin D receptor (VDR), 1-α hydroxylase (CYP27), 24 hydroxylase (CYP24) in monocytes lineage (U937). The U937 culture was incubated with healthy or CKD serum and treatment with/without 25-vitamin D (50 ng/ml for 24 h) to evaluate CD14, TRL4, VDR, CYP27 and CYP24 expression. This protocol showed the advantage to investigate the effect of treatment with 25 vitamin D on the intracellular and cell membrane biomarkers expression quickly and simultaneously. In addition, this technique is not laborious, but easy to perform and to interpret compared to RT-qPCR, western blot or immunofluorescence.

25-vitamin D reduces inflammation in uremic environment.

Chronic kidney disease (CKD) is characterized by loss of renal function and a consequent increase of serum uremic toxins, which contribute to inflammation status. Deficiency of 25-vitamin D, often found in patients with CKD, has been included as an inflammatory factor since it might modulate the immune system. The aim of this study was to investigate the role of 25-vitamin D on inflammatory pathways in healthy and uremic environment. Toll-like receptor 4 (TLR4), oxidative stress (ROS), vitamin D receptor (VDR), 1-α hydroxylase (CYP27), 24 hydroxylase, cathelicidin, and MCP-1 were evaluated in monocytes exposed to a uremic serum pool compared with healthy pool. The human monocytes lineage (U937) was incubated with or without 25-vitamin D (50 ng/ml for 24 hours). TRL4, VDR, CYP27, CYP24, and ROS were evaluated by flow cytometry. We used ELISA to measure IL-6, TNF-α, IL-10, cathelicidin, and MCP-1 in the cell culture supernatant. We observed a higher expression of TRL-4, IL-6, TNF-α, IL-10, cathelicidin and MCP-1 in monocytes incubated with uremic serum when compared with serum from healthy individuals. Supplementation of 25-vitamin D was able to reduce the expression of TRL4, cathelicidin, and MCP-1 in the uremic environment. There was no difference in the expression of VDR, CYP27 and CYP24 intracellular enzymes. This in vitro study showed that the uremic pool activates inflammatory response in monocytes, which was reversed by 25-vitamin D supplementation; this finding suggests that 25-vitamin D has an anti-inflammatory role in the uremic environment.

In vitro effect of uremic serum on barrier function and inflammation in human colonocytes.

INTRODUCTION: In chronic kidney disease (CKD), it has been suggested that alterations within the gut are associated with an inflammatory state and uremic toxicity. Studies suggest that uremia may impair the function of the intestinal barrier via the promotion of increased intestinal permeability. To understand the mechanisms that are involved in intestinal barrier damage in the setting of uremia, we evaluated the in vitro effect of uremic serum on transepithelial electrical resistance (TER), inflammation, and apoptosis in intestinal epithelial cells (T84). METHODS: Pools of serum from healthy individuals, patients not on dialysis, and patients on hemodialysis (Pre-HD and Post-HD) were prepared. T84 cells were incubated for 24 h in medium, of which 10% consisted of the pooled serum from each group. After incubation, the TER was measured and the following parameters were determined by flow cytometry: expression of toll-like receptors (TLRs), production of reactive oxygen species (ROS), and apoptosis. The level of IL-6 in the culture supernatant was determined by ELISA. RESULTS: No difference was observed among the groups with respect to TER, apoptosis, and ROS or the expression of TLR-2, TLR-4, and TLR-9. IL-6 secretion was higher (p < 0.001) in cells that were incubated with pre- and post-HD serum. CONCLUSION: The results that were obtained from this model suggest that uremic serum per se does not seem to impair the integrity of intestinal epithelial cells. The increased IL-6 secretion by cells that were incubated with HD serum suggests a potential effect of uremia in the intestinal inflammatory response.

Frequency of TGF- ß and IFN- γ genotype as risk factors for acute kidney injury and death in intensive care unit patients.

Genetic variations in TGF-ß and IFN-γ may interfere with proinflammatory cytokine production and, consequently, may be involved with inflammatory diseases, as acute kidney injury (AKI). We considered that genetic polymorphisms of these cytokines may have a crucial role in the outcome of critically ill patients. To investigate whether the genetic polymorphisms of rs1800470 (codon 10 T/C), rs1800471 (codon 25 C/G) from the TGF-ß, and rs2430561 (+874 T/A) from IFN-γ may be a risk factor for ICU patients to the development of AKI and/or death. In a prospective nested case-control study, were included 139 ICU patients who developed AKI, 164 ICU patients without AKI, and 244 healthy individuals. We observed a higher frequency to T/A genotype for IFN-γ (intermediate producer phenotype) and higher frequency of TT GG and TC GG genotype (high producer) for TGF-ß polymorphism in overall population. However, these polymorphisms have not been shown as a predictor of risk for AKI and death. We found an increased prevalence of high and intermediate producer phenotypes from TGF-ß and IFN-γ, respectively, in patients in ICU setting. However, the studied genetic polymorphism of the TGF-ß and IFN-γ was not associated as a risk factor for AKI or death in our population.

In vitro effect of uremic serum on barrier function and inflammation in human colonocytes / Efeito in vitro do soro urêmico sobre a função de barreira e inflamação em colonócitos humanos

ABSTRACT Introduction: In chronic kidney disease (CKD), it has been suggested that alterations within the gut are associated with an inflammatory state and uremic toxicity. Studies suggest that uremia may impair the function of the intestinal barrier via the promotion of increased intestinal permeability. To understand the mechanisms that are involved in intestinal barrier damage in the setting of uremia, we evaluated the in vitro effect of uremic serum on transepithelial electrical resistance (TER), inflammation, and apoptosis in intestinal epithelial cells (T84). Methods: Pools of serum from healthy individuals, patients not on dialysis, and patients on hemodialysis (Pre-HD and Post-HD) were prepared. T84 cells were incubated for 24 h in medium, of which 10% consisted of the pooled serum from each group. After incubation, the TER was measured and the following parameters were determined by flow cytometry: expression of toll-like receptors (TLRs), production of reactive oxygen species (ROS), and apoptosis. The level of IL-6 in the culture supernatant was determined by ELISA. Results: No difference was observed among the groups with respect to TER, apoptosis, and ROS or the expression of TLR-2, TLR-4, and TLR-9. IL-6 secretion was higher (p < 0.001) in cells that were incubated with pre- and post-HD serum. Conclusion: The results that were obtained from this model suggest that uremic serum per se does not seem to impair the integrity of intestinal epithelial cells. The increased IL-6 secretion by cells that were incubated with HD serum suggests a potential effect of uremia in the intestinal inflammatory response.

RESUMO Introdução: Tem sido sugerido que na doença renal crônica (DRC) a uremia pode causar alterações intestinais, tais como modificações na microbiota e danos à barreira intestinal, e que estas possíveis alterações podem ter uma relação importante com o estado inflamatório e a toxicidade urêmica apresentadas por pacientes com DRC. Objetivos: Avaliar o efeito in vitro do soro urêmico sobre a permeabilidade da monocamada de células epiteliais do intestino, inflamação e apoptose. Métodos: Pools de soro foram preparados a partir de soros de indivíduos saudáveis, pacientes em tratamento conservador e em hemodiálise (Pré e Pós-HD). As células T84 foram incubadas por 24 horas com os diferentes pools. Em seguida a TER foi medida e as células foram submetidas às seguintes análises: apoptose, produção de espécies reativas de oxigênio (EROs) e expressão de receptores toll-like (TLR) por citometria de fluxo e detecção de IL-6 no sobrenadante da cultura por ELISA. Resultados: Não foram encontradas diferenças, entre os grupos, com relação a TER, apoptose, EROs e expressão de TLR-2, TLR-4 e TLR-9. Já a secreção de IL-6 foi maior (p < 0,001) pelas células incubadas com soro pré-HD e pós-HD. Conclusão: Os resultados obtidos a partir deste modelo sugerem que a uremia per se parece não comprometer a integridade das células epiteliais do intestino. O aumento da secreção de IL-6 pelas células incubadas com soro HD (pré e pós) sugere um potencial efeito da uremia sobre a resposta inflamatória intestinal.