Janus Kinase Signal Research Articles

Deficiency in STAT1 Signaling Predisposes Gut Inflammation and Prompts Colorectal Cancer Development.

Signal transducer and activator of transcription 1 (STAT1) is part of the Janus kinase (JAK/STAT) signaling pathway that controls critical events in intestinal immune function related to innate and adaptive immunity. Recent studies have implicated STAT1 in tumor–stroma interactions, and its expression and activity are perturbed during colon cancer. However, the role of STAT1 during the initiation of inflammation-associated cancer is not clearly understood. To determine the role of STAT1 in colitis-associated colorectal cancer (CAC), we analyzed the tumor development and kinetics of cell recruitment in wild-type WT or STAT1−/− mice treated with azoxymethane (AOM) and dextran sodium sulfate (DSS). Following CAC induction, STAT1−/− mice displayed an accelerated appearance of inflammation and tumor formation, and increased damage and scores on the disease activity index (DAI) as early as 20 days after AOM-DSS exposure compared to their WT counterparts. STAT1−/− mice showed elevated colonic epithelial cell proliferation in early stages of injury-induced tumor formation and decreased apoptosis in advanced tumors with over-expression of the anti-apoptotic protein Bcl2 at the colon. STAT1−/− mice showed increased accumulation of Ly6G+Ly6C−CD11b+ cells in the spleen at 20 days of CAC development with concomitant increases in the production of IL-17A, IL-17F, and IL-22 cytokines compared to WT mice. Our findings suggest that STAT1 plays a role as a tumor suppressor molecule in inflammation-associated carcinogenesis, particularly during the very early stages of CAC initiation, modulating immune responses as well as controlling mechanisms such as apoptosis and cell proliferation.

Targeted regulationof STAT3 by miR-29a in mediating Taxol resistance of nasopharyngeal carcinoma cell line CNE-1.

STAT3 is an important molecule in Janus kinase (JAK) signal transducer and activator of transcription (STAT) signal pathway, and facilitates expression of various oncogenic genes such as Bcl-2, thus is correlated with tumor onset, progression and drug resistance. MiR-29a down-regulation is associated with the pathogenesis of nasopharyngeal carcinoma. Bioinformatics analysis demonstrated a complementary binding between miR-29a and 3'-UTR of STAT3. This study aims to investigate the role of miR-29a in regulating STAT3, as well as in Taxol resistance of nasopharyngeal carcinoma CNE-1 cells. Dual luciferase reporter gene assay showed a regulatory relationship between miR-29a and STAT3. Rhodamine 123 repository in CNE-1 and CNE1/Taxol drug resistant cells was measured together with the expression of miR-29a, STAT3, and p-STAT3. Flow cytometry was used to measure cell apoptosis and PCNA expression under Taxol treatment. CNE-1/Taxol cells were treated with miR-29a mimic and or si-STAT3, followed by measuring the expression of miR-29a, STAT3, and p-STAT3 and cell apoptosis. CCK-8 assay was performed to evaluate cell proliferation. MiR-29a inhibited STAT3 expression. Significantly lower Rhodamine 123 repository, miR-29a expression and apoptosis and higher expression of STAT3, p-STAT3 and PCNA were observed in CNE-2/ Taxol cells than those in CNE-1 cells. Transfection of miR-29a mimic and/or si-STAT3 decreased STAT3, p-STAT3 and PCNA expression, inhibited proliferation and promoted cell apoptosis. MiR-29a down-regulation is correlated with drug resistance of nasopharyngeal carcinoma cell line CNE-1 and MiR-29a up-regulation decreases Taxol resistance of nasopharyngeal carcinoma CNE-1 cells possibly via inhibiting STAT3 and Bcl-2 expression.

CUX1-ALK, a Novel ALK Rearrangement That Responds to Crizotinib in Non–Small Cell Lung Cancer

IntroductionLung cancer is the leading cause of cancer-related deaths worldwide. ALK receptor tyrosine kinase gene (ALK) rearrangement has been identified in 3% to 5% of patients with NSCLC. The most common ALK rearrangement is echinoderm microtubule associated protein like 4 (EML4)-ALK, with several variants that can be targeted by the tyrosine kinase inhibitor crizotinib. MethodsIn this study using comprehensive next-generation sequencing targeting 416 pan-cancer genes and introns of 16 genes frequently rearranged in cancer, we identified a novel cut-like homeobox 1 gene (CUX1)-ALK fusion gene in a patient with lung adenocarcinoma. The exact CUX1-ALK fusion transcript was determined by RNA sequencing and confirmed by reverse-transcriptase polymerase chain reaction. The oncogenic ability of CUX1-ALK fusion gene was further validated in cells of the line 293T for the activation of anaplastic lymphoma kinase (ALK) self-phosphorylation and downstream signaling pathways. ResultsAfter detection of the CUX1-ALK fusion gene, RNA sequencing analysis of formalin-fixed paraffin-embedded sections from the primary tumor specimen was applied to reveal a 97-nucleotide fragment from CUX1 intron 8 inserted before the nucleotide 53 position in ALK exon 20. Expression of the cut-like homeobox 1–ALK fusion protein in 293T cells confirmed the self-phosphorylation of the fusion protein and the activation of ALK downstream signaling pathways, including the mitogen-activated protein kinase, Janus kinase–signal transducer and activator of transcription, and phosphoinositide 3-kinase/AKT signaling pathways, which could all be inhibited by the addition of crizotinib. Furthermore, the patient showed a superior response to crizotinib, with a progression-free survival of 20 months. ConclusionsThis study provides the novel finding of a CUX1-ALK fusion gene from a patient with NSCLC that could provide personalized treatment solutions for the maximum benefit to patients with NSCLC.

Adoptive Transfer of Interleukin-21-stimulated Human CD8+ T Memory Stem Cells Efficiently Inhibits Tumor Growth.

Memory stem T (TSCM) cells, a new subset of memory T cells with self-renewal and multipotent capacities, are considered as a promising candidates for adoptive cellular therapy. However, the low proportion of human TSCM cells in total CD8+ T cells limits their utility. Here, we aimed to induce human CD8+ TSCM cells by stimulating naive precursors with interleukin-21 (IL-21). We found that IL-21 promoted the generation of TSCM cells, described as CD45RA+CD45RO−CD62L+CCR7+CD122+CD95+ cells, with a higher efficiency than that observed with other common γ-chain cytokines. Upon adoptive transfer into an A375 melanoma mouse model, these lymphocytes mediated much stronger antitumor responses. Further mechanistic analysis revealed that IL-21 activated the Janus kinase signal transducer and activator of transcription 3 pathway by upregulating signal transducer and activator of transcription 3 phosphorylation and consequently promoting the expression of T-bet and suppressor of cytokine signaling 1, but decreasing the expression of eomesodermin and GATA binding protein 3. Our findings provide novel insights into the generation of human CD8+ TSCM cells and reveal a novel potential clinical application of IL-21.

Systemic inhibition of Janus kinase induces browning of white adipose tissue and ameliorates obesity-related metabolic disorders

Browning of white adipose tissue is a promising strategy to tackle obesity. Recently, Janus kinase (JAK) inhibition was shown to induce white-to-brown metabolic conversion of adipocytes in vitro; however effects of JAK inhibition on browning and systemic metabolic health in vivo remain to be elucidated. Here, we report that systemic administration of JAK inhibitor (JAKi) ameliorated obesity-related metabolic disorders. Administration of JAKi in mice fed a high-fat diet increased UCP-1 and PRDM16 expression in white adipose tissue, indicating the browning of white adipocyte. Food intake was increased in JAKi-treated mice, while the body weight and adiposity was similar between the JAKi- and vehicle-treated mice. In consistent with the browning, thermogenic capacity was enhanced in mice treated with JAKi. Chronic inflammation in white adipose tissue was not ameliorated by JAKi-treatment. Nevertheless, insulin sensitivity was well preserved in JAKi-treated mice comparing with that in vehicle-treated mice. Serum levels of triglyceride and free fatty acid were significantly reduced by JAKi-treatment, which is accompanied by ameliorated hepatosteatosis. Our data demonstrate that systemic administration of JAKi has beneficial effects in preserving metabolic health, and thus inhibition of JAK signaling has therapeutic potential for the treatment of obesity and its-related metabolic disorders.

Oclacitinib em processos dermatológicos da medicina veterinária – revisão de literatura

The Janus kinase signal transducer and activator of transcription (JAK-STAT) pathway is utilized by cytokines, including interleukins (ILs), interferons (IFNs), and other molecules to transmit signal from the cell membrane to the nucleus. Inflammatory cytokines rely on JAK-STAT signaling, which is indispensable for immune and hematopoietic function. JAK inhibitors were developed for the treatment of a variety of inflammatory, immune-mediated, and hematopoietic disorders in humans. Evidence suggests that JAK inhibitors are efficacious in the treatment of atopic dermatitis, alopecia areata, psoriasis, and vitiligo. The first generation of JAK inhibitors included tofacitinib, ruxolitinib, baricitinib, and oclacitinib. Oclacitinib is used exclusively in veterinary medicine, and recent studies have shown that this drug has a rapid effect on pruritus and lesion reduction in dogs with atopic dermatitis. This article aimed to review this new class of drugs, focusing on the use of oclacitinib in veterinary medicine.

Increased neutrophil extracellular trap formation promotes thrombosis in myeloproliferative neoplasms.

Thrombosis is a major cause of morbidity and mortality in Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs), clonal disorders of hematopoiesis characterized by activated Janus kinase (JAK)-signal transducer and activator of transcription (STAT) signaling. Neutrophil extracellular trap (NET) formation, a component of innate immunity, has been linked to thrombosis. We demonstrate that neutrophils from patients with MPNs are primed for NET formation, an effect blunted by pharmacological inhibition of JAK signaling. Mice with conditional knock-in of Jak2V617F, the most common molecular driver of MPN, have an increased propensity for NET formation and thrombosis. Inhibition of JAK-STAT signaling with the clinically available JAK2 inhibitor ruxolitinib abrogated NET formation and reduced thrombosis in a deep vein stenosis murine model. We further show that expression of PAD4, a protein required for NET formation, is increased in JAK2V617F-expressing neutrophils and that PAD4 is required for Jak2V617F-driven NET formation and thrombosis in vivo. Finally, in a population study of more than 10,000 individuals without a known myeloid disorder, JAK2V617F-positive clonal hematopoiesis was associated with an increased incidence of thrombosis. In aggregate, our results link JAK2V617F expression to NET formation and thrombosis and suggest that JAK2 inhibition may reduce thrombosis in MPNs through cell-intrinsic effects on neutrophil function.

Low-Grade Dysplastic Nodules Revealed as the Tipping Point during Multistep Hepatocarcinogenesis by Dynamic Network Biomarkers.

Hepatocellular carcinoma (HCC) is a complex disease with a multi-step carcinogenic process from preneoplastic lesions, including cirrhosis, low-grade dysplastic nodules (LGDNs), and high-grade dysplastic nodules (HGDNs) to HCC. There is only an elemental understanding of its molecular pathogenesis, for which a key problem is to identify when and how the critical transition happens during the HCC initiation period at a molecular level. In this work, for the first time, we revealed that LGDNs is the tipping point (i.e., pre-HCC state rather than HCC state) of hepatocarcinogenesis based on a series of gene expression profiles by a new mathematical model termed dynamic network biomarkers (DNB)—a group of dominant genes or molecules for the transition. Different from the conventional biomarkers based on the differential expressions of the observed genes (or molecules) for diagnosing a disease state, the DNB model exploits collective fluctuations and correlations of the observed genes, thereby predicting the imminent disease state or diagnosing the critical state. Our results show that DNB composed of 59 genes signals the tipping point of HCC (i.e., LGDNs). On the other hand, there are a large number of differentially expressed genes between cirrhosis and HGDNs, which highlighted the stark differences or drastic changes before and after the tipping point or LGDNs, implying the 59 DNB members serving as the early-warning signals of the upcoming drastic deterioration for HCC. We further identified the biological pathways responsible for this transition, such as the type I interferon signaling pathway, Janus kinase–signal transducers and activators of transcription (JAK–STAT) signaling pathway, transforming growth factor (TGF)-β signaling pathway, retinoic acid-inducible gene I (RIG-I)-like receptor signaling pathway, cell adhesion molecules, and cell cycle. In particular, pathways related to immune system reactions and cell adhesion were downregulated, and pathways related to cell growth and death were upregulated. Furthermore, DNB was validated as an effective predictor of prognosis for HCV-induced HCC patients by survival analysis on independent data, suggesting a potential clinical application of DNB. This work provides biological insights into the dynamic regulations of the critical transitions during multistep hepatocarcinogenesis.

Newer treatments of psoriasis regarding IL-23 inhibitors, phosphodiesterase 4 inhibitors, and Janus kinase inhibitors.

The rapid progress of genetic engineering furthermore opens up new prospects in the therapy of this difficult-to-treat disease. IL-23 inhibitors, phosphodiesterase 4 (PDE4) inhibitors, and Janus kinase (JAK) inhibitors are currently encouraging further research. Two drugs which are IL-23 inhibitors are now in phase III of clinical trials. The aim of the action of both drugs is selective IL-23 inhibition by targeting the p19 subunit. Guselkumab is a fully human monoclonal antibody. Tildrakizumab is a humanized monoclonal antibody, which also belongs to IgG class and is targeted to subunit p19 of interleukin 23 (IL-23). Phosphodiesterase inhibitors exert an anti-inflammatory action and their most common group is the PDE4 family. PDE4 inhibits cAMP, which reduces the inflammatory response of the pathway of Th helper lymphocytes, Th17, and type 1 interferon which modulates the production of anti-inflammatory cytokines such as IL-10 interleukins. The Janus kinase (JAK) signaling pathway plays an important role in the immunopathogenesis of psoriasis. Tofacitinib suppresses the expression of IL-23, IL-17A, IL-17F, and IL-22 receptors during the stimulation of lymphocytes. Ruxolitinib is a selective inhibitor of JAK1 and JAK2 kinases and the JAK-STAT signaling pathway. This article is a review of the aforementioned drugs as described in the latest available literature.

MicroRNA‑24‑1‑5p promotes malignant melanoma cell autophagy and apoptosis via regulating ubiquitin D.

The present study aimed to investigate the key roles and possible regulatory mechanism of microRNA (miR)‑24‑1‑5p in regulating the autophagy, and apoptosis of malignant melanoma cells. The expression levels of miR‑24‑1‑5p in malignant melanoma tissues were determined. Human melanoma A375 cells were transfected with miR‑24‑1‑5p mimic and control. The effects of miR‑24‑1‑5p overexpression on regulating the expressions of autophagy‑related proteins [microtubule‑associated protein1A/1B‑light chain 3 (LC3)‑II, LC3‑I and Beclin‑1] and apoptosis‑related proteins [apoptosis regulator Bcl‑2 (Bcl‑2) and (BCL2 like 1) Bcl‑xL] were investigated. The percentage of apoptotic cells in different transfected cells was detected. In addition, luciferase reporter assays were performed to confirm whether ubiquitin D (UBD) was a target of miR‑24‑1‑5p. The effects of UBD silencing on autophagy and apoptosis were also investigated. The expression levels of janus kinase (JNK), phosphorylated (P)‑JNK, Jun proto‑oncogene AP‑1 transcription factor subunit (c‑Jun) and p‑c‑Jun were determined following the overexpression of miR‑24‑1‑5p, and UBD. In comparison with adjacent normal tissues, miR‑24‑1‑5p was significantly downregulated in malignant melanoma tissues. Overexpression of miR‑24‑1‑5p significantly increased the levels of LC3‑II/I ratio and Beclin‑1 expression, and decreased the expression levels of Bcl‑2 and Bcl‑xL. Flow cytometry also showed that miR‑24‑1‑5p overexpression promoted cell apoptosis. Moreover, UBD was confirmed as a direct target of miR‑24‑1‑5p. Silencing of UBD promoted melanoma cell autophagy and apoptosis via regulating the expression levels of related proteins. Besides, the levels of the p‑JNK/JNK and p‑c‑Jun/Jun ratios were significantly increased following miR‑24‑1‑5p overexpression, which were reversed following co‑overexpression of miR‑24‑1‑5p, and UBD. Overexpression of miR‑24‑1‑5p may target UBD, and subsequently promote the autophagy and apoptosis of malignant melanoma cells through activation of the JNK signaling pathway.

Inhibition of autophagy attenuated curcumol-induced apoptosis in MG-63 human osteosarcoma cells via Janus kinase signaling pathway.

The present study aimed to investigate whether autophagy was triggered by curcumol and to explore the association between autophagy and apoptosis of MG-63 cells and the underlying mechanism. MG-63 cells were cultured in vitro. An MTT assay was performed to evaluate the proliferation inhibition of the MG-63 osteosarcoma cell line by curcumol. Fluorescein isothiocyanate-Annexin V/propidium iodide staining flow cytometry was performed to analyze the apoptotic rate of cells. The morphological alterations of cell nuclei were evaluated by Hoechst 33258 viable cell staining. The effects of autophagy in cells was investigated by green fluorescent protein (GFP)-light chain 3 (LC3) transfection and using a fluorescence microscope. The expression levels of LC3II, LC3I and cleaved caspase-3 and Janus kinase (JNK) signaling pathway activation were determined by western blot analysis. Cell proliferation was inhibited by curcumol in a dose- and time-dependent manner. Curcumol induced apoptosis by the caspase-dependent signaling pathway in MG-63 cells. The present study demonstrated that curcumol could induce autophagy of MG-63 cells, which was evaluated by transmission electron microscopy. Compared with the curcumol treatment alone group, the GFP-LC3-transfected green fluorescence plasmids and the LC3II/LC3I levels in cells of the curcumol and chloroquine (CQ) treatment group were upregulated, and the apoptotic ratio was downregulated following pretreatment with autophagy inhibitor CQ for 1 h. Furthermore, curcumol treatment induced phosphorylation of the JNK signaling pathway. Of note, pretreatment with the JNK inhibitor, SP600125, decreased the rates of autophagy and apoptosis, suggesting a crucial role served by the JNK signaling pathway in the activation of autophagy by curcumol. Taken together, the results of the present study suggested that activation of the JNK signaling pathway was involved in curcumol-induced autophagy. Curcumol is a novel drug for chemotherapeutic combination therapy. Curcumol demonstrated potential antitumor activities in MG-63 cells and may be used as a novel effective reagent in the treatment of osteosarcoma.

The retinol-binding protein receptor STRA6 regulates diurnal insulin responses

It has long been appreciated that insulin action is closely tied to circadian rhythms. However, the mechanisms that dictate diurnal insulin sensitivity in metabolic tissues are not well understood. Retinol-binding protein 4 (RBP4) has been implicated as a driver of insulin resistance in rodents and humans, and it has become an attractive drug target in type II diabetes. RBP4 is synthesized primarily in the liver where it binds retinol and transports it to tissues throughout the body. The retinol-RBP4 complex (holo-RBP) can be recognized by a cell-surface receptor known as stimulated by retinoic acid 6 (STRA6), which transports retinol into cells. Coupled to retinol transport, holo-RBP can activate STRA6-driven Janus kinase (JAK) signaling and downstream induction of signal transducer and activator of transcription (STAT) target genes. STRA6 signaling in white adipose tissue has been shown to inhibit insulin receptor responses. Here, we examined diurnal rhythmicity of the RBP4/STRA6 signaling axis and investigated whether STRA6 is necessary for diurnal variations in insulin sensitivity. We show that adipose tissue STRA6 undergoes circadian patterning driven in part by the nuclear transcription factor REV-ERBα. Furthermore, STRA6 is necessary for diurnal rhythmicity of insulin action and JAK/STAT signaling in adipose tissue. These findings establish that holo-RBP and its receptor STRA6 are potent regulators of diurnal insulin responses and suggest that the holo-RBP/STRA6 signaling axis may represent a novel therapeutic target in type II diabetes.

Evaluation of novel SNPs and haplotypes within the <i>ATBF1</i> gene and their effects on economically important production traits in cattle

Abstract. AT motif binding factor 1 (ATBF1) gene can promote the expression level of the growth hormone 1 (GH1) gene by binding to the enhancers of the POU1F1 and PROP1 genes; thus, it affects the growth and development of livestock. Considering that the ATBF1 gene also has a close relationship with the Janus kinase–signal transductor and activator of transcription (JAK–STAT) pathway, the objective of this work was to identify novel single-nucleotide polymorphism (SNP) variations and their association with growth traits in native Chinese cattle breeds. Five novel SNPs within the ATBF1 gene were found in 644 Qinchuan and Jinnan cattle for first time using 25 pairs of screening and genotyping primers. The five novel SNPs were named as AC_000175:g.140344C>G (SNP1), g.146573T>C (SNP2), g.205468C>T (SNP3), g.205575A>G (SNP4) and g.297690C<T (SNP5). Among them, SNP1 and SNP2 were synonymous coding SNPs, while SNP5 was a missense coding SNP, and the other SNPs were intronic. Haplotype analysis found 18 haplotypes in the two breeds, and three and five closely linked loci were revealed in Qinchuan and Jinnan breeds, respectively. Association analysis revealed that SNP1 was significantly associated with the height across the hip in Qinchuan cattle. SNP2 was found to be significantly related to chest circumference and body side length traits in Jinnan cattle. SNP3 was found to have significant associations with four growth traits in Qinchuan cattle. Moreover, the different combined genotypes, SNP1–SNP3, SNP1–SNP4 and SNP2–SNP5 were significantly associated with the growth traits in cattle. These findings indicated that the bovine ATBF1 gene had marked effects on growth traits, and the growth-trait-related loci can be used as DNA markers for maker-assisted selection (MAS) breeding programs in cattle.

Downregulation of BRAF-activated non-coding RNA suppresses the proliferation, migration and invasion, and induces apoptosis of hepatocellular carcinoma cells.

The long non-coding RNA BRAF-activated non-coding RNA (BANCR) has been reported to serve essential roles in the progress of a various cancer types. The purpose of the present study was to investigate the effect of lncRNA BANCR in HCC cells. The expression of BANCR in the HCC cell line Huh7 and a normal liver cell line were determined using reverse transcription-quantitative polymerase chain reaction. The expression of BANCR in Huh7 cells was downregulated by short hairpin (sh)RNA. Subsequently, the proliferation, apoptosis, migration and invasion rates were determined, along with the activity of MAPK/ERK kinase (MEK) and mitogen-activated protein kinase signaling pathways. The results revealed that BANCR was overexpressed in Huh7 cells when compared with normal liver cells. The downregulation of BANCR significantly inhibited the proliferation and colony formation ability, and induced cell cycle arrest and apoptosis of Huh7 cells. The migration and invasion of Huh7 cells were also suppressed in BANCR shRNA-transfected cells. The downregulation of BANCR significantly inhibited the activity of MEK, extracellular signal-regulated kinase and janus kinase signaling pathways. Collectively, these findings demonstrated that the lncRNA BANCR is oncogenic in Huh7 cells, and may be a promising molecular target for HCC therapy.

Atopic dermatitis treatment: Current state of the art and emerging therapies.

Atopic dermatitis (AD) can be debilitating and often requires the use of combination topical and systemic therapy to achieve adequate disease control. A non-systematic review was performed of current state of the art and emerging therapies for AD. There are a number of topical agents approved by the U.S. Food and Drug Administration (FDA) for the treatment of AD and multiple nonapproved systemic agents that are used off label for the treatment of AD. All of these have limitations of efficacy and/or safety, which leads to a number of unmet disease-treatment needs. Recent insight has identified a number of novel pathways as treatment targets for AD, including the T-helper type 2 cytokines, interleukins (IL) 4, IL-13, IL-33, phosphodiesterase E 4, and Janus kinase signaling. Dupilumab is a monoclonal antibody that inhibits interleukin 4 and 13 signaling and was recently approved by the FDA for the treatment of moderate-severe AD in adults. There are a number of current treatment approaches and emerging therapies for AD.

Magnesium Reduces Hepatic Lipid Accumulation in Yellow Catfish (Pelteobagrus fulvidraco) and Modulates Lipogenesis and Lipolysis via PPARA, JAK-STAT, and AMPK Pathways in Hepatocytes

BackgroundMagnesium influences hepatic lipid deposition in vertebrates, but the underlying mechanism is unknown. ObjectiveWe used yellow catfish and their isolated hepatocytes to test the hypothesis that magnesium influences lipid deposition by modulating lipogenesis and lipolysis. MethodsJuvenile yellow catfish (mean ± SEM weight: 3.43 ± 0.02 g, 3 mo old, mixed sex) were fed a 0.14- (low), 0.87- (intermediate) or 2.11- (high) g Mg/kg diet for 56 d. Primary hepatocytes were incubated for 48 h in control or MgSO4-containing medium with or without 2-h pretreatment with an inhibitor (AG490, GW6471, or Compound C). Growth performance, cell viability, triglyceride (TG) concentrations, and expression of enzymes and genes involved in lipid metabolism were measured. ResultsCompared with fish fed low magnesium, those fed intermediate or high magnesium had lower hepatic lipids (18%, 22%) and 6-phosphogluconate dehydrogenase (6PGD; 3.7%, 3.8%) and malic enzyme (ME; 35%, 48%) activities and greater mRNA levels of the lipolytic genes adipose triacylglyceride lipase (atgl; 82% and 1.7-fold) and peroxisome proliferator-activated receptor (ppara; 18% and 1.0-fold), respectively (P < 0.05). Relative mRNA levels of AMP-activated protein kinase (ampk) a1, ampka2, ampkb1, ampkb2, ampkg1a, ampkg1b, Janus kinase (jak) 2a, jak2b, and signal transducers and activators of transcription (stat) 3 in fish fed high magnesium were higher (24% to 3.1-fold, P < 0.05) than in those fed low or intermediate magnesium. Compared with cells incubated with MgSO4 alone, those incubated with MgSO4 and pretreated with AG490, GW6471, or Compound C had greater TG concentrations (42%, 31%, or 56%), g6pd (98%, 59%, or 51%), 6pgd (68%, 73%, or 32%) mRNA expression, and activities of G6PD (35%, 45%, or 16%) and ME (1.5-fold, 1.3-fold, or 13%), and reduced upregulation (61%, 25%, or 45%) of the lipolytic gene, atgl (P < 0.05). ConclusionsMagnesium reduced hepatic lipid accumulation in yellow catfish and the variation might be attributed to inhibited lipogenesis and increased lipolysis. PPARA, JAK-STAT, and AMPK pathways mediated the magnesium-induced changes in lipid deposition and metabolism. These results offer new insight into magnesium nutrition in vertebrates.

Sensory neurons co-opt classical immune signaling pathways to mediate chronic itch

Abstract Mammals have evolved neurophysiologic reflexes such as scratching to expel invading pathogens and noxious environmental factors. It is also well established that these responses are associated with chronic inflammatory diseases such as atopic dermatitis. However, the mechanisms by which inflammatory pathways promote sensations such as itch remain poorly understood. Here, we show that the type 2 cytokines interleukin (IL)-4 and IL-13 directly stimulate sensory neurons and that chronic itch is dependent on neuronal IL-4Rα, the shared receptor subunit for IL-4 and IL-13. Based on our understanding of IL-4Rα signaling in immune cells, we hypothesized that downstream Janus kinase (JAK) signaling in sensory neurons would be a critical mediator of itch. Indeed, we find that both systemic JAK inhibition and interruption of JAK signaling in the nervous system can dramatically reduce itch. Further, sensory neuron-specific genetic deletion of JAK1 results in robust abatement of chronic itch in mice. Finally, in proof-of-concept translational studies, patients with recalcitrant chronic itch improved rapidly and dramatically in response to JAK inhibition. Thus, signaling mechanisms previously ascribed to the immune system may represent novel targets within the sensory nervous system for the treatment of pathologic sensory responses. Collectively, these studies reveal an evolutionarily conserved paradigm in which the sensory nervous system employs classical immune signaling pathways to influence mammalian behavior.

Effect of SOCS1 silencing on proliferation and apoptosis of melanoma cells: An in vivo and in vitro study.

This study aimed to investigate the effect of SOCS1 silencing on the proliferation and apoptosis of melanoma cells by in vivo and in vitro studies. Immunohistochemical staining was used to detect SOCS1 expression in melanoma tissues and pigmented nevi. Quantitative real-time polymerase chain reaction and western blotting were applied to detect the messenger RNA and protein expressions of SOCS1 in primary human melanocytes and malignant melanoma cell lines (A375, SK-MEL-5, M14, and MV3). Melanoma cells were assigned into mock, negative small interfering RNA, and SOCS1-small interfering RNA groups. The proliferation, cell cycle and apoptosis, and messenger RNA expression of SOCS1 in MV3 and A375 cells were detected using MTT assay, flow cytometry, and quantitative real-time polymerase chain reaction, respectively. The expressions of SOCS1 protein, extracellular signal-regulated kinase, and janus kinase signal transduction and activators of transcription signaling pathways-related proteins were detected using western blotting. After the establishment of subcutaneous xenograft tumor models in nude mice, the latent period, size, volume and growth speed of xenograft tumors in the mock, negative small interfering RNA, and SOCS1-small interfering RNA groups were examined and compared. The results indicated that positive expression rate of SOCS1 was higher in malignant melanoma tissues than in pigmented nevi. MV3 cells had the highest messenger RNA and protein expressions of SOCS1, followed by A357 cells. Compared with the mock and negative small interfering RNA groups, SOCS1-small interfering RNA group showed lower cell viability, elevated cell apoptosis, more cells in G0/G1 phase and less cells in S and G2/M phases, and decreased messenger RNA and protein expressions of SOCS1, p-ERK1/2, p-JAK2, p-STAT1, and p-STAT3. Compared with the mock and negative small interfering RNA groups, the SOCS1-small interfering RNA group showed longer latent period of tumor, smaller tumor size and volume, and smoother tumor growth curve. To conclude, SOCS1 silencing can inhibit proliferation and induce apoptosis of MV3 and A357 melanoma cells in vivo and in vitro by inhibiting extracellular signal-regulated kinase and janus kinase signal transduction and activators of transcription signaling pathways.

Tofacitinib attenuates arthritis manifestations and reduces the pathogenic CD4 T cells in adjuvant arthritis rats

Rheumatoid arthritis (RA) is an autoimmune disease characterized by pronounced inflammation and leukocyte infiltration in affected joints.Tofacitinib is new agent, a selective inhibitor of Janus kinase (JAK) signaling pathways mediated by JAK1 and JAK3 and inhibits the key transcription factors STAT1 and STAT3.We investigated the action mechanisms of tofacitinib in rats with adjuvant-induced-arthritis (AIA). AIA-rats were treated orally with tofacitinib or with methotrexate. Arthritis severity and serum C-reactive protein (CRP) levels were evaluated, splenic cells were examined by flow cytometry and cytokines were analyzed by real-time PCR.Tofacitinib markedly reduced the clinical status of treated rats in comparison to control group. Reduced joints inflammation and down-regulated serum CRP levels reflected the clinical manifestations of the treated rats. Tofacitinib down-regulated significantly the frequency of CD4+IFN-γ+ T cells and reduced IL-1β mRNA expression levels in the spleen of the treated rats.These results show that tofacitinib attenuated arthritis severity, modified splenic populations and cytokine imbalance.

Tumor Necrosis Factor Inhibits Spread of Hepatitis C Virus Among Liver Cells, Independent From Interferons

Tumor necrosis factor (TNF) is an inflammatory cytokine expressed by human fetal liver cells (HFLCs) after infection with cell culture-derived hepatitis C virus (HCV). TNF has been reported to increase entry of HCV pseudoparticles into hepatoma cells and inhibit signaling by interferon alpha (IFNα), but have no effect on HCV-RNA replication. We investigated the effects of TNF on HCV infection of and spread among Huh-7 hepatoma cells and primary HFLCs. Human hepatoma (Huh-7 and Huh-7.5) and primary HFLCs were incubated with TNF and/or recombinant IFNA2A, IFNB, IFNL1, and IFNL2 before or during HCV infection. We used 2 fully infectious HCV chimeric viruses of genotype 2A in these studies: J6/JFH (clone 2) and Jc1(p7-nsGluc2A) (Jc1G), which encodes a secreted luciferase reporter. We measured HCV replication, entry, spread, production, and release in hepatoma cells and HFLCs. TNF inhibited completion of the HCV infectious cycle in hepatoma cells and HFLCs in a dose-dependent and time-dependent manner. This inhibition required TNF binding to its receptor. Inhibition was independent of IFNα, IFNβ, IFNL1, IFNL2, or Janus kinase signaling via signal transducer and activator of transcription. TNF reduced production of infectious viral particles by Huh-7 and HFLC, and thereby reduced the number of infected cells and focus size. TNF had little effect on HCV replicons and increased entry of HCV pseudoparticles. When cells were incubated with TNF before infection, the subsequent antiviral effects of IFNs were increased. In a cell culture system, we found TNF to have antiviral effects independently of, as well as in combination with, IFNs. TNF inhibits HCV infection despite increased HCV envelope glycoprotein-mediated infection of liver cells. These findings contradict those from other studies, which have reported that TNF blocks signal transduction in response to IFNs. The destructive inflammatory effects of TNF must be considered along with its antiviral effects.