Category: neursciene research

That miR-21 controls LPS actions has been shown. Sheedy et al have shown that miR-21 inhibits the production of IL-6 and enhances IL-10 levels by controlling both NFκB p65 levels and the proinflammatory molecule tumor suppressor programmed cell death 4, an inhibitor of IL-10 production. These findings are not in perfect agreement with ours, since we found that miR-21 -/- elicited macrophages show enhanced IL-6 and IL-10 levels, whereas Sheedy et al. show that miR-21 mimic enhances IL-6 and decrease IL-10 levels. The reason for this discrepancy is uncertain, but there are several differences in the respective experiments. Sheedy et al studied miR-21 effects in a macrophage cell line and bone marrow derived macrophages; whereas, we performed our experiments in thioglycollate-elicited macrophages, which exhibit an inflammatory phenotype. Also, we investigated the role of miR-21 in basal/homeostatic expression of these cytokines, and Sheedy et al determined the production of IL-16 and IL-10 in LPS-stimulated cells. Whether thioglycollate-elicited miR-21 deficient macrophages respond to LPS in the same manner as cell lines or bone marrow macrophages remains to be determined. Our results are in agreement with Shi et al. who showed in a model of colitis that M1-like cytokines such as TNF-αand MIP-2 are decreased in miR-21 deficient mice. Clearly, the elucidation of such cell-specific functions of miR-21 should help in the development of effective miR-based therapeutic strategies. Here, we investigated the role of the cAMP inducer PGE2 in the expression of miR-21 in macrophages. Our data show that PGE2 challenge decreased miR-21 expression, and incubation of macrophages with the downstream effectors PKA or the Epac agonist also decreased miR-21 levels. Whether the cAMP/PKA/Epac axis influences global microRNA expression and their effects in macrophage biology remains to be determined. These data lead us to speculate that miR-21 acts as a brake on PGE2 effects, and PGE2-mediated miR-21 inhibition is part of an inhibitory loop ASP1517 involved in macrophage M2 polarization by the PGE2/PKA/Epac axis. The molecular mechanisms involved in miR-21 and PGE2-induced M2 macrophages were studied. Initially, we tested whether miR-21 inhibition influenced EP 1–4 mRNA expression, but we did not observe any differences in the expression of these receptors between WT and miR-21 -/- cells or WT cells treated with miR-21 mimic. We also did not observe any change in the expression of the CREB. We next investigated which transcription factors and effectors were involved in enhanced expression of M2 genes. While STAT6 is activated by IL-4 and IL-13, and has been suggested to be the master regulator of M2 differentiation, STAT1 and NFκB are thought to be essential for M1 generation. We did not observe a change in the expression of STAT6 and phosphorylation in miR-21-/- macrophages, which led us to study the expression of other STAT proteins in miR-21 deficient cells, and to ask whether PGE2 further influenced the expression of these proteins.

Finally, S100A9 protein acts as an independent predictor when compared to standard biomarkers. Previously restricted to the simple identification of protein sample, the recent progresses in mass spectrometry allow the quantification of MLN4924 proteins within complex matrices. The so-called “label free” approach enables protein relative quantification in several samples based on the comparison of intensities of peptide ion currents observed during LC separations. This challenging technology is accurate and robust enough to estimate protein ratios after adequate statistical processing. Although initiated to draw a global picture, this work was focused on two proteins of interest, namely S100A8 and S100A9 proteins. These two proteins are constitutively expressed in neutrophils and monocytes but also in macrophages during acute or chronic inflammation. They are associated with various infectious or inflammatory diseases. Recently, some studies have shown that biological therapies modulate the expression of S100 proteins. Indeed, the expression of several genes, including those coding for S100A12 and S100A8 proteins was lower in PBMCs after treatment with etanercept or adalimumab. Besides, the level of soluble calprotectin was shown to decrease and to be associated to ultrasonographic synovitis scores in RA patients treated by adalimumab. Thus, calprotectin might be of additional value in the assessment of RA patients under biologic treatment. However, even though levels of S100 proteins appear to be influenced by TBAs, their theranostic value has never been demonstrated until now. So far, these proteins have only been identified as diagnostic and prognostic markers of RA. Furthermore, these proteins are found at high concentrations in the serum of RA patients. A high correlation is observed between flares and elevated concentration of these proteins, making the latter interesting inflammatory markers, reflecting the disease activity. Here, proteomic investigations were firstly performed with PBMCs because these cells and several cytokines produced by them have a pivotal role in RA pathogenesis and are targeted by ETA. Specifically, in the context of RA, PBMCs constitute an advantageous surrogate tissue as they allow for screening in any subject, whereas synovium is only accessible through an invasive procedure. Additionally, proteomic investigations on PBMCs benefit from a reduced dynamic range of protein concentration compared to serum. The results of this first part of the study demonstrated a similar over-expression of S100A8 and S100A9 proteins in the cellular PBMC proteome, where they might appear as a heterodimeric complex. Thereafter, we investigated the “theranostic” potential of S100 proteins in sera from R and NR patients to ETA/MTX combination. In contrast to PBMC investigations, this study only revealed a significant overexpression of the S100A9 protein in R patients, confirmed by ELISA absolute quantification. Conversely, ELISA revealed a similar expression of S100A8 and calprotectin in both R and NR groups.

However, it has not been clearly demonstrated whether these soluble cell surface PF-04217903 receptors in the plasma are actually originated from the tumor cells. In one study sAXL was detected in the tumor exudates of xenograft mice ; however, the authors used an antibody that detected both murine and human AXL. Hence, the origin of sAXL was not addressed. Furthermore, it has been argued that the increased levels of sAXL seen in the patients did not originate from the tumor cells. The claim was solely based on the lack of correlation between the tumor size and serum levels of AXL in renal cancer patients. In our study the levels of sAXL seem to be correlated with the level of AXL in MPNST cells. In all four MPNST cell lines as well as in the NHSC, the release of sAXL was maintained at constant rate over time in serum free media. As expected, the release of sAXL was the lowest in S462 and NHSC corresponding to the relatively low levels of cellular AXL.. Further, knockdown of AXL reduced the levels of sAXL to the same extend as the reduction of AXL mRNA and protein levels. Furthermore, human sAXL can be detected in the plasma from xenograft mice. Treatment with photodynamic Lipo-ce6 reduced the tumor size and the sAXL levels accordingly. Taken together these findings argue that the sAXL in the plasma originates from the tumor cells, and it might be useful to evaluate sAXL as tumor burden marker in NF1 patients. The role of AXL in the MPNST cells is still unclear. In our study, silencing the expression of AXL did not affect cell proliferation or the subcutaneous tumor growth, but resulted in a slight but significant down regulation of cell migration. In epithelial ovarian cancer, AXL was over-expressed in the advanced metastatic tumors compared to the low grade tumors. The authors noticed reduced tumor growth after intraperitoneal injections of the tumor cells and an adenovirus carrying sAXL was able to reduce the growth of these xenograft tumors. In addition, GAS6-AXL signaling has recently been shown to increase Schwannoma cell matrix adhesion and survival, further arguing for an involvement of AXL in Schwann cell tumorigenesis. Interestingly, the levels of sAXL seem to be more evenly distributed in the female patients compared to the male patients. In the male dermal neurofibroma patients, one patient stood out with 49 ng/ml sAXL compared to the other 16 patients that had between 11.5–20.6 ng/ml. This patient had extreme numbers of neurofibromas, including spinal tumors along all major nerves. Hence, a high sAXL level in this patient supports the general idea of sAXL as tumor burden marker. Within the dermal neurofibroma group, the four male patients with more than 100 dermal neurofibromas, had significant higher sAXL levels than the ten male patients with less than 30 dermal neurofibromas. As a group these high dermal tumor burden patients had comparable levels to the male plexiform patients. In contrast, some of the mild female NF1 patients and even some of the female controls had high levels of sAXL.

In the context of cancer, miRNAs in serum from patients with breast cancer and diffuse large-B-cell lymphoma have been shown to be stable and highly predictive of malignancy and survival. These reports suggest significant roles for extracellular miRNAs, in addition to those of tissue miRNAs, in regulating many physiological processes. As this field develops, these miRNAs may become diagnostic and therapeutic targets in clinically relevant situations. These reports promoted us to speculate that miRNAs may be present and stable in human bile, just as they are in other bodily fluids, and that bile-borne miRNAs could be used as novel biomarkers for BTC. The major components of human bile are bile acid, cholesterol, bilirubin, bicarbonates, electrolytes, and water. Bile is produced by hepatocytes in the liver and flows via the bile duct into the duodenum, where it assists in lipid digestion and absorption. Like blood, bile can be collected from patients who undergo diagnostic and/or therapeutic bile drainage. One can therefore understand the utility of a BTC biomarker in bile and/or serum. A bile biomarker could expedite the diagnosis of BTC by prompting further histological examinations such as bile cytology, brush cytology, and forceps biopsy of the bile duct. In this study, we first examined whether miRNAs exist and can be detected in human bile by small RNA library sequencing. Next, we determined whether the expression of specific miRNAs in bile differs between patients with cancer and those without cancer using high-throughput real-time PCR-based miRNA expression microarrays. Finally, we assessed the potential of bile miRNAs as novel biomarkers for BTC. Here, we report on the presence and stability of bile miRNAs, their relative expression levels, as measured by high-throughput real-time PCR, and differences in the miRNA profiles between bile samples from patients with benign and malignant biliary tract disease. After confirming the existence of miRNAs in bile using specific miRNA primers, we performed a more comprehensive analysis using miRNA microarrays, which allowed us to test for the presence of 667 miRNA species. Although this is a small study, we have confidence that our concept of using miRNAs to distinguish benign/malignant biliary tract diseases will be validated as more large-scale studies are conducted in the future. In addition to proposing the diagnostic use of bile miRNAs, we have developed reliable methods for extracting and evaluating miRNAs that are compatible with clinical CHIR-99021 msds testing.

Abolition of the miRNA pathway in the Nav1.8 population of nociceptive neurons attenuated inflammatory pain. We postulated that altered miRNA levels after peripheral nerve Dasatinib 302962-49-8 injury can contribute to growth programs that promote axonal regeneration. Here we show that an axotomyregulated miRNA, miR-21, promotes neurite growth from injured adult DRG neurons by targeting the Sprouty2 protein. Our results uncover a role for miRNAs in regulating axonal regeneration following peripheral nerve injury. Sciatic nerve injury activates transcription factors such as c-Jun, ATF3 and Stat3, which in turn modulate gene expression and stimulate axon growth to reconnect with peripheral targets. Here we investigated if sciatic nerve injury induced changes in small noncoding RNAs that can regulate gene expression at the post-transcriptional level. Using a microarray screen we identified 8 miRNAs that were regulated after axotomy. We further show that miR-21 enhanced neurite outgrowth in adult rat DRG neurons. This, to our knowledge, is the first time a regenerative role for miR-21 in neurons has been demonstrated. Of the 8 miRNAs that were regulated after axotomy, only miR431 and miR-138 have been shown to be expressed in the central nervous system. miR-223 appears to be predominantly present in hematopoietic cells but interestingly has been shown to be highly expressed in neutrophils that are present in the spinal cord during the early phase of spinal cord injury. miR-431 was found to be present in embryonic and postnatal mouse brains but levels were lower in adult mouse brains. miR-383 is expressed in germ cells and has been shown to target interferon regulatoryfactor 1, a transcription factor that controls expression of genes related to inflammation and injury. IRF-1 expression is increased in neurons following ischaemic injury and it is plausible that decreased miR-383 in the DRG following axotomy can modulate signalling cascades through IRF-1. miR-138 is interesting as it is highly enriched in the synapse and negatively regulates dendritic spine size by targeting the depalmitoylation enzyme acyl protein thioesterase 1. Interestingly in the same paper, miR-21 also exhibited significant increased expression in rat synaptosomes compared to whole forebrain extract. miR-21 is a commonly dysregulated miRNA in many forms of cancer and cardiovascular disease however its function in the nervous system has not been examined. We showed that miR-21 was significantly increased in the DRG 2 days after axotomy, and that this increase was sustained up to 28 days post-injury.