The relationship between deiodinase activity and inflammatory responses under the stimulation of uremic toxins

Effects of Selenium and/or N-Acetyl-Cysteine Supplementation on Nonthyroidal Illness Syndrome in Hemodialysis Patients: A Factorial Randomized Controlled Trial

INTRODUCTION

Nonthyroidal illness syndrome (NTIS) is common in hemodialysis patients (HPs). However, limited clinical trials have been conducted in this field. Therefore, the aim of this study was to investigate the effect of Se and/or N-acetyl-cysteine (NAC) on NTIS parameters in HPs.

METHODS

In this factorial randomized controlled trial, 68 HPs were divided into four groups: group A received placebo of Se and NAC, group B received 600 μg per day of NAC and placebo of Se, group C received 200 μg of Se per day and placebo of NAC and group D received 200 μg of selenium and 600 μg of NAC per day for 12 weeks. Blood samples were taken at baseline and after 12 weeks to assess free tri-iodothyronine (FT3), free thyroxine (FT4), thyroid stimulating hormone (TSH), and reverse T3 (rT3) concentrations.

RESULTS

Our finding demonstrated that rT3 levels were decreased in B, C, and D groups and increased nearly to baseline levels in the A group after 12 weeks, with a marked difference between the groups (p < 0.001) based on ANOVA. Although there were no significant differences in FT3 (p = 0.39), FT4 (p = 0.76), and TSH (p = 0.71) between the groups at the end of the trial.

CONCLUSION

This trial showed that Se and/or NAC exert beneficial effects on rT3 levels in HPs. However, long-term clinical trials with a larger sample size using more appropriate biomarkers are recommended to evaluate the efficacy and safety of Se and/or NAC in HPs.

Selenium as a Bioactive Micronutrient in the Human Diet and Its Cancer Chemopreventive Activity

This review answers the question of why selenium is such an important trace element in the human diet. Daily dietary intake of selenium and its content in various food products is discussed in this paper, as well as the effects of its deficiency and excess in the body. Moreover, the biological activity of selenium, which it performs mainly through selenoproteins, is discussed. These specific proteins are responsible for thyroid hormone management, fertility, the aging process, and immunity, but their key role is to maintain a redox balance in cells. Furthermore, taking into account world news and the current SARS-CoV-2 virus pandemic, the impact of selenium on the course of COVID-19 is also discussed. Another worldwide problem is the number of new cancer cases and cancer-related mortality. Thus, the last part of the article discusses the impact of selenium on cancer risk based on clinical trials (including NPC and SELECT), systematic reviews, and meta-analyses. Additionally, this review discusses the possible mechanisms of selenium action that prevent cancer development.

Correlations between related-purine derivatives and renal disorders in patients with psoriasis vulgaris

Recent data suggest that severe psoriasis is an independent risk factor for chronic renal disease. In the present study, we investigated the role of related-purine derivatives as predictors of renal dysfunctions in patients with psoriasis. A prospective study was conducted on a group of 45 patients with psoriasis vulgaris and 45 control cases, monitored over a 5-year period. Alterations of renal function, albumin/creatinine ratio (ACR, mg/g) and UA/creatinine ratio (UACR, mg/mg) were determined in spontaneous urine samples. The status of related-purine derivatives was evaluated by quantification of uric acid (UA, mg/dl), adenosine deaminase (ADA, UI/mg protein), xanthine oxidase (XO, UI/mg protein) and 8-hydroxy-deoxy-guanosine levels (8-OHdG, ng/ml) in serum samples. Compared to the controls, in patients with psoriasis there was an increase in related-purine derivatives levels, which was demonstrated by the elevated serum levels of UA (5.1±0.4 vs. 5.4±1.0, P=0.066), ADA (0.14±0.08 vs. 0.29±0.12, P=0.052), XO (0.22±0.11 vs. 0.42±0.21, P=0.011) and 8-OHdG (3.1±0.05 vs. 8.3±4.7, P=0.002). The serum levels of related-purine derivatives were associated with the severity of psoriasis. In addition, there was a link between the serum levels of related-purine derivatives and markers of renal impairment. There were positive correlations between 8-OHdG and ACR (r=0.452, P=0.028) and between ADA, XO, UA, 8-OHdG and UACR (r=0.297 and P=0.032, r=0.301 and P=0.002, r=0.431 and P=0.027, r=0.508 and P=0.002) and negative correlations between UA, 8-OHdG and the estimated glomerular filtration rate (r=-0.301 and P=0.036, r=-0.384 and P=0.002). Thus, severe psoriasis is a risk factor for the development of renal disease.

miR-29a-3p/T-bet Regulatory Circuit Is Altered in T Cells of Patients With Hashimoto's Thyroiditis

OBJECTIVE

Hashimoto's thyroiditis (HT) is a common autoimmune thyroid disorder that frequently evolves from asymptomatic, T-cell mediated chronic inflammation toward overt hypothyroidism. Previously, we have demonstrated a role for T-bet, a T helper 1/CD8⁺ T cell transcription factor (TF), and FoxP3, a regulatory T cell TF, in disease progression and severity, but the basis behind their altered mRNA expression remains unknown. In this study, we aimed to leverage the role for microRNAs, representing negative transcriptional regulators, across the spectrum of HT clinical presentations using the same, well-characterized RNA sample cohort.

METHOD

Ten hypothyroid, untreated patients (hypoHT), 10 hypothyroid cases rendered euthyroid by l-thyroxine therapy (substHT), 11 spontaneously euthyroid HT subjects (euHT), and 10 healthy controls (ctrl) were probed for three candidate immunoregulatory miRNA (miR-9-5p, miR-29a-3p, and miR-210-3p) using quantitative real-time PCR measurements. Data were normalized to U6snRNA and fold difference in expression calculated by the efficiency corrected 2^-ΔΔCt model.

RESULTS

Compared to healthy controls, peripheral blood (PB) T cells of HT patients exhibited significantly diminished miR-29a-3p expression levels [median expression levels (IQR), HT vs CTRL, 0.62 (0.44-1.01) vs 1.373 (0.63-2.7), P = 0.046], and a similar, but not significant decline in miR-210-3p abundance [HT vs CTRL, 0.64 (0.39-1.31) vs 1.2 (0.5-2.56), P = 0.24, Wilcoxon test]. A significant inverse correlation was observed between the two differentially expressed transcripts, T-bet mRNA and miR-29a-3p. Moreover, altered miR-29a-3p/T-bet expression in T cells of untreated HT patients was related to low serum FT4, high serum thyrotropin, and decreased thyroid volumes. Of note, miR-210-3p expression was positively correlated to HIF1α, and inversely to FoxP3 mRNA levels, but no evidence of differential expression for any of these miRNA-mRNA pairs was observed. Finally, miR-9-5p expression levels were no different in HT vs control comparisons, or related to clinicopathological features.

CONCLUSION

T cell miR-29a-3p is downregulated in HT patients and associated with clinical and biochemical parameters of progressive thyroid injury, plausibly subsequent to altered control of T-bet expression in PB T cells. As such miR-29a-3p/T-bet axis should be further explored as a biomarker or as a plausible target for therapeutic interventions in HT.

The cyclic AMP signaling pathway: Exploring targets for successful drug discovery (Review)

During development of disease, complex intracellular signaling pathways regulate an intricate series of events, including resistance to external toxins, the secretion of cytokines and the production of pathological phenomena. Adenosine 3′,5′-cyclic monophosphate (cAMP) is a nucleotide that acts as a key second messenger in numerous signal transduction pathways. cAMP regulates various cellular functions, including cell growth and differentiation, gene transcription and protein expression. This review aimed to provide an understanding of the effects of the cAMP signaling pathway and the associated factors on disease occurrence and development by examining the information from a new perspective. These novel insights aimed to promote the development of novel therapeutic approaches and aid in the development of new drugs.

Antioxidant therapy improves non-thyroidal illness syndrome in uremic rats

BACKGROUND

The roles of antioxidant therapy on non-thyroidal illness syndrome (NTIS) in uremic rats is still unclear.

MATERIALS AND METHODS

Twenty-four Sprague-Dawley (SD) rats were randomly divided into blank, 5/6 nephrectomy (Nx), pyrrolidine dithiocarbamate (PDTC, 10 mg/100 g), sodium bicarbonate (SB, 0.1 g/100 g), N-acetylcysteine (NAC, 80 mg/100 g) and thyroid hormones (TH, levothyroxine 2 μg/100 g) groups. The serum levels of malondialdehyde (MDA), superoxide dismutase (SOD), advanced oxidation protein products (AOPP), interleukin (IL)-1β, free triiodothyronine (FT3), and thyroid stimulating hormone (TSH) were detected in the sixth week. The expressions of IL-1β and deiodinase type 1 (DIO1) were assessed by western blotting. The nuclear factor kappa B (NF-κB) inflammatory signal pathway was confirmed by electrophoretic mobility shift assay (EMSA).

RESULTS

Compared with 5/6 Nx group, PDTC and NAC significantly reduced the levels (p < 0.01, respectively) of serum MDA, AOPP, TSH, and elevated levels of serum SOD (p < 0.01, respectively) and FT3 (p = 0.016 and p < 0.01). Neither had significant effects on serum IL-1β content (p = 0.612 and p = 0.582). PDTC and NAC markedly decreased the protein expression of IL-1β (p < 0.01) and increased the protein expression of DIO1 (p < 0.01), respectively. Both had been considerably blunted NF-κB activity (p < 0.01).

CONCLUSIONS

In uremic rat model, PDTC and NAC can effectively improve oxidative stress level and NTIS. In terms of improving oxidative stress level, NAC is probably superior to PDTC.

Gene-specific regulation of hepatic selenoprotein expression by interleukin-6

Sepsis is a severe inflammatory disease resulting in excessive production of pro-inflammatory cytokines including interleukin-6 (IL-6), causing oxidative stress, tissue damage and organ dysfunction. Health benefits have been observed upon selenium (Se) supplementation in severe sepsis. Selenium is incorporated into selenoproteins implicated in anti-oxidative defence, thyroid hormone metabolism and immunoregulation. Selenium metabolism is controlled by hepatocytes synthesizing and secreting the Se transporter selenoprotein P (SePP). The circulating SePP declines in sepsis causing low serum Se levels. Dysregulation of the hepatic selenoenzyme deiodinase type 1 (DIO1) potentially contributes to the low T3 (thyroid hormone) syndrome observed in severe diseases. We hypothesized that IL-6 affects hepatic selenoprotein biosynthesis directly. Testing human hepatocytes in culture, IL-6 reduced the concentrations of SePP mRNA and secreted SePP in a dose-dependent manner. In parallel, expression of DIO1 declined at the mRNA, protein and enzyme activity level. The effects of IL-6 on glutathione peroxidase (GPX) expression were isozyme-specific; GPX1 remained unaffected, while transcript concentrations of GPX2 increased and those of GPX4 decreased. This pattern of IL-6-dependent effects was mirrored in reporter gene experiments with SePP, DIO1, GPX1, and GPX2 promoter constructs pointing to direct transcriptional effects of IL-6. The redirection of hepatic selenoprotein biosynthesis by IL-6 may represent a central regulatory circuit responsible for the decline of serum Se and low T3 concentrations in sepsis. Accordingly, therapeutic IL-6 targeting may be effective for improving the Se and thyroid hormone status, adjuvant Se supplementation success and survival in sepsis.

The cardiovascular disease risks of nonthyroidal illness syndrome and inflammatory responses on patients with chronic kidney disease: from the association to clinical prognosis

BACKGROUND

Previous data have suggested the potential risk of low serum-free triiodothyronine (FT3) on the cardiovascular disease (CVD) events in patients with end-stage renal disease (ESRD). However, the roles of FT3 and interleukin-6 (IL-6) in the developing of CVD events in patients with chronic kidney disease (CKD) have not been investigated.

PATIENTS AND METHODS

A total of 176 consecutive patients with CKD underwent thyroid function, IL-6, and echocardiography evaluation. They were divided into two subgroups: group I, 77 patients with IL-6 >200 ng/L, and group II, 99 patients with IL-6 <200 ng/L. The total patients were also divided into two subgroups according to their serum FT3: group A, 83 patients with FT3 <4.0 pmol/L, and group B, 93 patients with FT3 >4.0 pmol/L.

RESULTS

Serum FT3 (β = -0.21, P < 0.01), IL-6 (β = 0.48, P < 0.01), and glutathione peroxidase (GSH-Px, β = -0.58, P < 0.01) were found independently associated with left ventricular mass index (LVMI). Patients with higher IL-6 had significantly higher CVD incidence than those with IL-6 <200 ng/L (HR 1.98, P = 0.014); Patients with lower FT3 had significantly higher CVD incidence than those with FT3 >4.0 pmol/L (HR 1.81, P = 0.038), when extensive demographics, comorbidities and laboratory adjustments were made.

CONCLUSIONS

Serum levels of FT3 and IL-6 were associated with the LVMI and previous CVD events; lower FT3 and higher IL-6 were strong predictors of subsequent CVD events in patients with CKD.