MicroRNAs as Regulators of Phagocytosis.

MicroRNAs (miRNAs) are short non-coding RNAs that regulate gene expression and thus act as important regulators of cellular phenotype and function. As their expression may be dysregulated in numerous diseases, they are of interest as biomarkers. What is more, attempts of modulation of some microRNAs for therapeutic reasons have been undertaken. In this review, we discuss the current knowledge regarding the influence of microRNAs on phagocytosis, which may be exerted on different levels, such as through macrophages polarization, phagosome maturation, reactive oxygen species production and cytokines synthesis. This phenomenon plays an important role in numerous pathological conditions.

The Impact of Cytokines on Neutrophils' Phagocytosis and NET Formation during Sepsis-A Review.

Sepsis is an overwhelming inflammatory response to infection, resulting in multiple-organ injury. Neutrophils are crucial immune cells involved in innate response to pathogens and their migration and effector functions, such as phagocytosis and neutrophil extracellular trap (NET) formation, are dependent on cytokine presence and their concentration. In the course of sepsis, recruitment and migration of neutrophils to infectious foci gradually becomes impaired, thus leading to loss of a crucial arm of the innate immune response to infection. Our review briefly describes the sepsis course, the importance of neutrophils during sepsis, and explains dependence between cytokines and their activation. Moreover, we, for the first time, summarize the impact of cytokines on phagocytosis and NET formation. We highlight and discuss the importance of cytokines in modulation of both processes and emphasize the direction of further investigations.

MiR-181a-5p Regulates NIS Expression in Papillary Thyroid Carcinoma.

NIS is a potent iodide transporter encoded by the SLC5A5 gene. Its expression is reduced in papillary thyroid carcinoma (PTC). In this study we analyzed the impact of miR-181a-5p on NIS expression in the context of PTC. We used real-time PCR to analyze the expression of SLC5A5 and miR-181a-5p in 49 PTC/normal tissue pairs. Luciferase assays and mutagenesis were performed to confirm direct binding of miR-181a-5p to the 3'UTR of SLC5A5 and identify the binding site. The impact of modulation of miR-181a-5p using appropriate plasmids on endogenous NIS and radioactive iodine accumulation was verified. We confirmed downregulation of SLC5A5 and concomitant upregulation of miR-181a-5p in PTC. Broadly used algorithms did not predict the binding site of miR-181a-5p in 3'UTR of SLC5A5, but we identified and confirmed the binding site through mutagenesis using luciferase assays. In MCF7 and HEK293-flhNIS cell lines, transfection with mir-181a-expressing plasmid decreased endogenous SLC5A5, whereas silencing of miR-181a-5p increased it. We observed similar tendencies in protein expression and radioactive iodine accumulation. This study shows for the first time that miR-181a-5p directly regulates SLC5A5 expression in the context of PTC and may decrease efficacy of radioiodine treatment. Accordingly, miR-181a-5p may serve as an emerging target to enhance the efficacy of radioactive iodine therapy.

Phagocytosis, Degranulation and Extracellular Traps Release by Neutrophils-The Current Knowledge, Pharmacological Modulation and Future Prospects.

Neutrophils are crucial elements of innate immune system, which assure host defense via a range of effector functions, such as phagocytosis, degranulation, and NET formation. The latest literature clearly indicates that modulation of effector functions of neutrophils may affect the treatment efficacy. Pharmacological modulation may affect molecular mechanisms activating or suppressing phagocytosis, degranulation or NET formation. In this review, we describe the role of neutrophils in physiology and in the course of bacterial and viral infections, illustrating the versatility and plasticity of those cells. This review also focus on the action of plant extracts, plant-derived compounds and synthetic drugs on effector functions of neutrophils. These recent advances in the knowledge can help to devise novel therapeutic approaches via pharmacological modulation of the described processes.

A Novel Germline c.1267T>A MEN1 Mutation in MEN1 Family-from Phenotype to Gene and Back.

Primary hyperparathyroidism is a relatively common endocrine disorder, which may be hereditary. This report describes clinical, biochemical, radiographic, and genetic findings, the latter obtained using next generation sequencing (NGS), in three consanguineous patients. Gene panels in NGS consisted of 5 or 70 genes, including MEN1 and RET. The first patient suffered from recurrent primary hyperparathyroidism. Primary hyperparathyroidism and pituitary microadenomas were afterwards diagnosed in two of her daughters. No clinical nor radiological features of gastroenteropancreatic neuroendocrine tumors were found. All three family members were heterozygous for MEN1 NM_130799: c.1267T>A transversion, which is predicted to result in substitution of tryptophan with arginine in position 423. Additionally, the first patient was also a carrier of RET NM_020975: c.1946C>T missense mutation, which was not present in two other family members. We describe a family with a novel heterozygous mutation (NM_130799: c.1267T>A) in MEN1 gene and postulate that it leads to MEN1 syndrome. The study underlies the importance of genetic testing in primary hyperparathyroidism in personalizing patients' care.

Alantolactone Enhances the Phagocytic Properties of Human Macrophages and Modulates Their Proinflammatory Functions.

AIM OF THE STUDY: Phagocytosis is a crucial element of innate immune defense involved in bacterial killing. The aim of our study was to evaluate the influence of alantolactone on phagocytosis and cytokines release by THP1-derived macrophages. We assessed whether antimicrobial compound alantolactone (a sesquiterpene lactone present in Inula helenium L.) is able to stimulate immune functions of macrophages by increase of S. aureus uptake, phagosome acidification and further stimulation of phago-lysosomes formation. Simultaneously, we tested influence of alantolactone on cytokines/chemokines production and p65 NF-κB concentration. The activity of alantolactone was compared with clarithromycin at concentration 20 µM. METHODS: The cytotoxicity of alantolactone as well as S. aureus uptake, pH of phagosomes and phago-lysosomes fusion were analysed with flow cytometry. Reactive oxygen species and superoxide production were evaluated spectrophotometrically. The efficiency of phagocytosis was evaluated via quantifying viable bacteria (CFU). The effect on p65 protein concentration and cytokine production by macrophages were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: Alantolactone enhanced phagocytosis via increase of S. aureus uptake, acidification of phagosomes, and later stimulation of phago-lysosomes fusion. Alantolactone treatment resulted in ROS and superoxide production decrease. Furthermore, alantolactone inhibited production of pro-inflammatory cytokines TNF-α, IL-1ß, IL-6, and IL-8 as well as decreased p65 concentration, the subunit responsible for NF-κB activation and cytokine production and simultaneously stimulated release of anti-inflammatory mediators (IL-10 and TGF-ß). CONCLUSION: Results of our study indicate that alantolactone enhances clearance of S. aureus, and simultaneously modulates immune response, preventing collateral damage of the surrounding tissues. Considering the importance of phagocytosis in the pathogen killing, alantolactone may have a great potential as the supportive treatment of S. aureus infections. Further in vivo studies are warranted to confirm this hypothesis.

Grindelia squarrosa Extract and Grindelic Acid Modulate Pro-inflammatory Functions of Respiratory Epithelium and Human Macrophages.

Aim of the study: Both nasal and bronchial epithelial cells have evolved sophisticated mechanisms involved in cellular response to bacterial infection. Recognition of pathogens by TLR receptors activate the NF-κB transcription factor, and lead to production of wide spectrum of cytokines (TNF-α, IL-1ß, IL-6 and IL-8). Released by epithelium proinflammatory cytokines intensify migration of macrophages to damaged tissues and modulate their pro-inflammatory functions. Based on traditional use of G. squarrosa aerial parts we hypothesized that successful treatment of cold-related diseases may arise from modulation of the pro-inflammatory functions of respiratory epithelium and human monocytes/macrophages. The biological activity of G. squarrosa extract and grindelic acid were compared with clarithromycin and budesonide used as positive controls. Methods: The expression of surface receptors (TLR-4, IL-10) and expression of adhesive molecules (ICAM-1, VCAM-1, E-selectin) was analyzed with flow cytometry. The macrophage attachment to the epithelial cells was assessed fluorimetrically. The p65 NF-κB concentration and cytokine production was measured spectrophotometrically using enzyme-linked immunosorbent assay. Antibacterial activity was examined by the standard disc-diffusion method and serial dilution method according to CLSI guidelines. Results: G. squarrosa extract and grindelic acid had no antimicrobial effect. However, we noticed significant modulation of pro-inflammatory functions of LPS-stimulated nasal and bronchial epithelium. G. squarrosa extract treatment resulted in decrease of TLR-4 expression and p65 NF-κB concentration and inhibition of cytokines synthesis (IL-8, TNF-α, IL-1ß and IL-6) in both cellular models. Additionally, G. squarrosa extract slightly modulated ICAM-1 expression affecting on attachment of macrophages to epithelium. Only G. squarrosa extract was able to stimulate the anti-inflammatory functions of macrophages by inducing TGF-ß release and IL-10 receptor surface expression. Grindelic acid, identified as a dominant compound in the plant extract, modulated pro-inflammatory functions of epithelium and macrophages slightly. Conclusion: The obtained results support traditional use of Grindelia squarrosa preparations for a treatment cold-associated diseases symptoms. In our opinion, the observed biological effect of extract may be a consequence of synergistic effect of all compounds present in the extract.

Inula helenium and Grindelia squarrosa as a source of compounds with anti-inflammatory activity in human neutrophils and cultured human respiratory epithelium.

ETHNOPHARMACOLOGICAL RELEVANCE: During the epidemic season, over 90% of acute wheezing disease is associated with bronchial inflammation. Both neutrophil- and eosinophil-mediated inflammation have been involved in the pathophysiology of acute bronchitis, but neutrophil cell recruitment has been shown to be dominant. The ongoing inflammation increases the chemotaxis of neutrophils to inflamed site providing to their overaccumulation. The pharmacological reduction of neutrophil migration can be limited by suppression of major chemo-attractants and cytokines (IL-8, IL-1ß and TNF-α) release and downregulation of adhesive molecules. AIM OF THE STUDY: During a screening of plants traditionally used in respiratory tracts diseases (e.g. cough, rhinitis, bronchitis, throat infection, fever, influenza) in Europe, we have selected roots of Inula helenium and aerial parts of Grindelia squarrosa as a potential source of compounds limiting neutrophil migration. MATERIALS AND METHODS: The effect on IL-8, IL-1ß and TNF-α release by neutrophils and respiratory epithelium cell line (A549) was measured by enzyme-linked immunosorbent assay (ELISA). The surface expression of adhesive molecules was analyzed with flow cytometry, and the neutrophil attachment to the epithelial cells was assessed fluorimetrically. RESULTS: We confirmed the ability of selected extracts and compounds to suppress neutrophil binding to the epithelium surface via downregulation of ß2 integrin. Alantolactone and grindelic acid have shown significant suppression of IL-8, TNF-α and IL-1ß release comparable with budesonide, used as a positive control. CONCLUSIONS: The present study demonstrated that Inula helenium and Grindelia squarrosa, which have been traditionally used in Europe as medicinal plants, are a valuable source of active compounds with anti-inflammatory activity. Our observations justify the traditional use of I. helenium and G. squarrosa for a treatment of inflammation-based diseases in respiratory tract.

The rs2910164 Genetic Variant of miR-146a-3p Is Associated with Increased Overall Mortality in Patients with Follicular Variant Papillary Thyroid Carcinoma.

Aberrant expression of the sodium-iodide symporter (NIS) and the resistance to post-operative radioactive iodide treatment is a crucial cause of higher mortality of some thyroid cancer patients. In this study, we analyzed the impact of miR-146a on the expression and function of NIS and on the overall survival of thyroid cancer patients. The study included 2441 patients (2163 women; 278 men); including 359 cases with follicular variant of papillary thyroid carcinoma (fvPTC). miR:NIS interactions were analyzed in cell lines using in vivo binding and inhibition assays and radioactive iodine uptake assays. Tumor/blood DNA was used for rs2910164 genotyping. Overall survival was assessed retrospectively. In the results, we showed that miR-146a-3p directly binds to and inhibits NIS. Inhibition of miR-146a-3p restores the expression and function of NIS, increasing radioactive iodine uptake. Rs2910164 functional variant within miR-146a-3p is associated with increased overall mortality among fvPTC female patients. The deaths per 1000 person-years were 29.7 in CC carriers vs. 5.08 in GG/GC-carriers (HR = 6.21, p = 0.006). Higher mortality of CC vs. GG/GC carriers was also observed in patients with lower clinical stage (HR = 22.72, p < 0.001), smaller tumor size (pT1/pT2) (HR = 25.05, p < 0.001), lack of extrathyroidal invasion (HR = 9.03, p = 0.02), lack of nodular invasion (HR = 7.84, p = 0.002), lack of metastases (HR = 6.5, p = 0.005) and older (age at diagnosis >50 years) (HR = 7.8, p = 0.002). MiR-146a-3p underwent somatic mutations in 16.1% of analyzed specimens, mainly towards the deleterious C allele. In this report we propose a novel molecular marker of the clinical outcome of fvPTC patients. Rs2910164 increases the overall mortality with inhibition of NIS and disruption of radioiodine uptake as a possible mechanism.

Association between GWAS-Derived rs966423 Genetic Variant and Overall Mortality in Patients with Differentiated Thyroid Cancer.

PURPOSE: Five germline genetic variants (rs116909374, rs965513, rs944289, rs966423, and rs2439302) have been associated in genome-wide association studies (GWAS) with increased risk of differentiated thyroid cancer (DTC), but their role in mortality of patients has not been established. Also, no preoperative marker of the clinical outcome of thyroid cancer had yet been identified. The aim of the study was to investigate the relationship between the variants and overall mortality in patients with DTC. EXPERIMENTAL DESIGN: Retrospective study of 1,836 patients (1,643 women, 193 men) with median age at diagnosis of 49 years and overall median follow-up time of 8.7 years after initial treatment at a single comprehensive cancer center between 1990 and 2013. RESULTS: Among 5 variants, rs966423 was associated with increased mortality, which was 6.4% (33 of 518) versus 3.7% (47 of 1,259) in TT carriers versus CC/CT carriers (P = 0.017). The HR of TT versus TC/CC carriers was 1.6 [95% confidence interval (CI), 1.02-2.49; P = 0.038] after adjustment for age at diagnosis and sex. Importantly, the association of rs966423 with mortality remained valid when clinicopathologic risk factors were included in the model (HR, 1.89; 95% CI, 1.14-3.13; P = 0.014). Higher rs966423-associated patient mortality of TT versus CC/CT carriers was also observed in interaction with angioinvasion (adjusted HR, 3.48; 95% CI, 1.67-7.22; P < 0.001), lymph node metastasis (adjusted HR, 3.47; 95% CI, 1.16-10.4; P = 0.018), extrathyroidal invasion (adjusted HR, 2.07; 95% CI, 1.15-3.73; P = 0.013). CONCLUSIONS: The presence of the rs966423-TT genotype was associated with a significant increase in overall mortality of patients with DTC. Contrary to BRAF mutation and other somatic changes, the status of germline rs966423 is known before the treatment and might be used in the management of mortality risk by means of modification of therapy.

Next generation sequencing reveals microRNA isoforms in liver cirrhosis and hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) represents the major histological subtype of liver cancer. Tumorigenic changes in hepatic cells potentially result from aberrant expression of microRNAs (miRNAs). Individual microRNA gene may give rise to miRNAs of different length, named isomiRNAs that proved to be functionally relevant. Since microRNA length heterogeneity in hepatic tissue has not been described before, we employed next-generation sequencing to comprehensively analyze microRNA transcriptome in HCC tumors (n=24) and unaffected tissue adjacent to tumors (n=24), including samples with (n=15) and without cirrhosis (n=9). We detected 374 microRNAs expressed in liver, including miR-122-5p that constituted over 39% of the hepatic miRnome. Among the liver expressed miRs, the levels of 64 significantly differed between tumor and control samples (FDR<0.05, fold change>2). Top deregulated miRNAs included miR-1269a (T/N=22.95), miR-3144-3p (T/N=5.24), miR-183-5p (T/N=4.63), miR-10b-5p (T/N=3.87), miR-490-3p (T/N=0.13), miR-199a-5p (T/N=0.17), miR-199a-3p/miR-199b-3p (T/N=0.19), miR-214-5p (T/N=0.20) and miR-214-3p (T/N=0.21). Almost all miRNA genes produced several mature molecules differing in length (isomiRNAs). The reference sequence was not the most prevalent in 38.6% and completely absent in 10.5% of isomiRNAs. Over 26.1% of miRNAs produced isoforms carrying≥2 alternative seed regions, of which 35.5% constituted novel, previously unknown seeds. This fact sheds new light on the percentage of the human genome regulated by microRNAs and their variants. Among the most deregulated miRNAs, miR-199a-3p/miR-199b-3p (T/N fold change=0.18, FDR=0.005) was expressed in 9 isoforms with 3 different seeds, concertedly leading to upregulation of TGF-beta signaling pathway (OR=1.99; p=0.004). In conclusion, the study reveals the comprehensive miRNome of hepatic tissue and provides new tools for investigation of microRNA-dependent pathways in cirrhotic liver and hepatocellular carcinoma. This article is part of a Directed Issue entitled: Rare Cancers.

Ultra-rare mutation in long-range enhancer predisposes to thyroid carcinoma with high penetrance.

Thyroid cancer shows high heritability but causative genes remain largely unknown. According to a common hypothesis the genetic predisposition to thyroid cancer is highly heterogeneous; being in part due to many different rare alleles. Here we used linkage analysis and targeted deep sequencing to detect a novel single-nucleotide mutation in chromosome 4q32 (4q32A>C) in a large pedigree displaying non-medullary thyroid carcinoma (NMTC). This mutation is generally ultra-rare; it was not found in 38 NMTC families, in 2676 sporadic NMTC cases or 2470 controls. The mutation is located in a long-range enhancer element whose ability to bind the transcription factors POU2F and YY1 is significantly impaired, with decreased activity in the presence of the C- allele compared with the wild type A-allele. An enhancer RNA (eRNA) is transcribed in thyroid tissue from this region and is greatly downregulated in NMTC tumors. We suggest that this is an example of an ultra-rare mutation predisposing to thyroid cancer with high penetrance.

Cumulative risk impact of five genetic variants associated with papillary thyroid carcinoma.

BACKGROUND: Two recent genome-wide association studies (GWASs) identified five single nucleotide polymorphisms (SNPs; rs965513, rs944289, rs966423, rs2439302, and rs116909374) associated with papillary thyroid carcinoma (PTC). Each variant showed highly significant but moderate to low disease risk. Here we assessed the cumulative risk and predictive value of the five SNPs. METHODS: We genotyped two cohorts of individuals, 747 PTC cases and 1047 controls from Ohio and 1795 PTC cases and 2090 controls from Poland. Cumulative genetic risk scores were calculated using unweighted and weighted approaches. RESULTS: All five SNPs showed significant association with PTC. The average cumulative risk score in cases was significantly higher than in controls (p<2.2×10(-16)). Each additional risk allele increased the risk of having PTC by 1.51 [95% confidence interval (CI) 1.4, 1.64] in Ohio and by 1.35 [95% CI 1.27, 1.44] in Poland. An analysis was performed weighing risk alleles by effect size and assigning individuals to three weighted risk score groups, low (≤2), medium (2-5), and high (>5). Individuals in the high group were significantly more susceptible to PTC compared with individuals in the low group with an odds ratio of 8.7 [95% CI 5.8, 13.3] in Ohio and 4.24 [95% CI 3.10, 5.84] in Poland. Almost identical results were obtained when follicular variant PTCs and microPTCs were omitted. These five SNPs explained 11% of the familial risk of thyroid cancer in the Ohio cohort and 6% in the Polish cohort. CONCLUSION: As the genetic risk score increases, the risk of having PTC increases. However, the predictive power of the cumulative effect of these five variants is only moderately high and clinical use may not be feasible until more variants are detected.