A two-amino-acid substitution in the transcription factor RORγt disrupts its function in TH17 differentiation but not in thymocyte development.

The transcription factor RORγt regulates differentiation of the TH17 subset of helper T cells, thymic T cell development and lymph-node genesis. Although elimination of RORγt prevents TH17 cell-mediated experimental autoimmune encephalomyelitis (EAE), it also disrupts thymocyte development, which could lead to lethal thymic lymphoma. Here we identified a two-amino-acid substitution in RORγt (RORγtM) that 'preferentially' disrupted TH17 differentiation but not thymocyte development. Mice expressing RORγtM were resistant to EAE associated with defective TH17 differentiation but maintained normal thymocyte development and normal lymph-node genesis, except for Peyer's patches. RORγtM showed less ubiquitination at Lys69 that was selectively required for TH17 differentiation but not T cell development. This study will inform the development of treatments that selectively target TH17 cell-mediated autoimmunity but do not affect thymocyte development or induce lymphoma.

Correction: Oncogenic Herpesvirus KSHV Hijacks BMP-Smad1-Id Signaling to Promote Tumorigenesis.

[This corrects the article DOI: 10.1371/journal.ppat.1004253.].

Exploring the Role of Clustered Mutations in Carcinogenesis and Their Potential Clinical Implications in Cancer.

Abnormal cell proliferation and growth leading to cancer primarily result from cumulative genome mutations. Single gene mutations alone do not fully explain cancer onset and progression; instead, clustered mutations-simultaneous occurrences of multiple mutations-are considered to be pivotal in cancer development and advancement. These mutations can affect different genes and pathways, resulting in cells undergoing malignant transformation with multiple functional abnormalities. Clustered mutations influence cancer growth rates, metastatic potential, and drug treatment sensitivity. This summary highlights the various types and characteristics of clustered mutations to understand their associations with carcinogenesis and discusses their potential clinical significance in cancer. As a unique mutation type, clustered mutations may involve genomic instability, DNA repair mechanism defects, and environmental exposures, potentially correlating with responsiveness to immunotherapy. Understanding the characteristics and underlying processes of clustered mutations enhances our comprehension of carcinogenesis and cancer progression, providing new diagnostic and therapeutic approaches for cancer.

Orchestrating Cellular Balance: ncRNAs and RNA Interactions at the Dominant of Autophagy Regulation in Cancer.

Autophagy, a complex and highly regulated cellular process, is critical for the maintenance of cellular homeostasis by lysosomal degradation of cellular debris, intracellular pathogens, and dysfunctional organelles. It has become an interesting and attractive topic in cancer because of its dual role as a tumor suppressor and cell survival mechanism. As a highly conserved pathway, autophagy is strictly regulated by diverse non-coding RNAs (ncRNAs), ranging from short and flexible miRNAs to lncRNAs and even circRNAs, which largely contribute to autophagy regulatory networks via complex RNA interactions. The potential roles of RNA interactions during autophagy, especially in cancer procession and further anticancer treatment, will aid our understanding of related RNAs in autophagy in tumorigenesis and cancer treatment. Herein, we mainly summarized autophagy-related mRNAs and ncRNAs, also providing RNA-RNA interactions and their potential roles in cancer prognosis, which may deepen our understanding of the relationships between various RNAs during autophagy and provide new insights into autophagy-related therapeutic strategies in personalized medicine.

USP19 Suppresses Th17-Driven Pathogenesis in Autoimmunity.

Th17 cells have emerged as a chief pathogenic cell type in murine models of autoimmunity and human autoimmune diseases. Th17 cells are markedly plastic in their pathogenic potential, as they can adopt pro- or anti-inflammatory programming under distinct conditions. The specific mechanism underlying the plasticity of Th17 pathogenesis remains elusive. In this study, we found that Th17 lineage-specific transcription factor RORγt directly bound to the promoters of genes engaged in the ubiquitination pathway and thus upregulated their expression in pathogenic Th17 cells. We observed that ubiquitination activity correlated with Th17-related pathology in the context of autoimmunity. Consistent with this finding, the deubiquitinase USP19 was shown to suppress pathogenic Th17 differentiation in vitro and Th17-mediated pathogenesis in vivo. Mechanistically, USP19 removed the K63-linked ubiquitin chain from RORγt lysine 313, which is essential for recruiting the coactivator SRC3. Collectively, our findings indicate that USP19 selectively suppresses the pathogenic potential of Th17 cells and offer novel strategies for treating autoimmune diseases.

SRC3 Is a Cofactor for RORγt in Th17 Differentiation but Not Thymocyte Development.

SRC3, a highly conserved member of the steroid receptor coactivator (SRC) family, is recruited by transcription factors to regulate cellular function. Previously, we demonstrated that SRC1, another highly conserved member of the SRC family, interacts with RORγt to regulate Th17 differentiation. However, the relationship between SRC1 and SRC3 in the regulation of Th17 cell function remains unknown. In this study, we demonstrate that mouse SRC3 interacts with RORγt in Th17 cells but not in thymocytes. In addition, Src3-/- mice exhibited defective Th17 differentiation and induction of experimental autoimmune encephalomyelitis but normal thymocyte development. Furthermore, a K313 to arginine mutation of RORγt (RORγt-K313R), which disrupts the interaction of RORγt with SRC3 but not with SRC1, impairs Th17 differentiation but not thymocyte development. These data suggest that SRC3 works with SRC1 to regulate RORγt-dependent Th17 differentiation but is not essential for RORγt-dependent thymocyte development.

SRC1 promotes Th17 differentiation by overriding Foxp3 suppression to stimulate RORγt activity in a PKC-θ-dependent manner.

Th17 cells are major players in multiple autoimmune diseases and are developmentally contingent on reciprocal functionality between the transcription factor Retineic acid receptor-related orphan nuclear receptor gamma (RORγt) and Forkhead box protein P3 (Foxp3). Here we deciphered a previously unappreciated role of Steroid receptor coactivator 1 (SRC1) in defining the lineage decision for the development of Th17 versus induced T-regulatory (iTreg) cells. We demonstrate that SRC1 functions as a critical coactivator for RORγt in vivo to promote the functional dominance of RORγt over Foxp3 and thus establishing an unopposed Th17 differentiation program. In the absence of SRC1, T cell polarization resulted in decreased IL-17+ and increased Foxp3+ cells during both in vitro differentiation and in vivo development of experimental autoimmune encephalomyelitis. Mechanistically, T cell receptor (TCR) signaling molecule protein kinase C theta (PKC-θ)-mediated phosphorylation of SRC1 is important for inducing enhanced RORγt-SRC1 interaction, stable DNA binding, and resultant IL-17A transcription. Furthermore, phospho-SRC1-mediated recruitment of CARM1 induced prominent asymmetric dimethylation of H3R17 while preventing repressive H3K9 trimethylation and hence further modifying the IL-17 locus for optimal transcription. Moreover, binding of phospho-SRC1 to RORγt displaced bound Foxp3, leading to prompt degradation of the dissociated Foxp3 via a ubiquitin-proteosomal pathway and hence reversing the inhibitory action of Foxp3 on RORγt activity. Thus, SRC1 acts as a crucial molecular mediator to integrate positive PKC-θ-dependent TCR signals to induce peak RORγt activity and establish phenotypic dominance of Th17 over the iTreg pathway.

Isoliquiritin promote angiogenesis by recruiting macrophages to improve the healing of zebrafish wounds.

Licorice is a widely used herbal medicine for the treatment of various diseases in southern Europe and parts of Asia. It has been reported that the isoliquiritin (ISL) from Glycyrrhiza root has the activity of promoting angiogenesis. The purpose of this study was to investigate the effect of ISL on the wound healing activity of zebrafish and its mechanism. 6-month-old zebrafish were injured in the skin (2 mm in diameter) and then treated with ISL. By measuring wound size and by histological examination, we found that ISL improved wound healing. In addition, 4-day-old zebrafish embryos of double transgenic line [Tg(fli-1:EGFP)]/[Tg(mpeg:mCherry)] were suffered from tissue traumas and then treated with ISL. Through fluorescent microscopy, we found that ISL promoted macrophage recruitment and angiogenesis in the wound area. Through qPCR analysis, we found that ISL up-regulated the expression of genes related to inflammation and angiogenesis in zebrafish embryos. These results showed that ISL could promote inflammatory response and angiogenesis, which played key roles in promoting wound healing. Therefore, ISL can be used as a promising candidate to promote wound healing.

TCF-1 Inhibits IL-17 Gene Expression To Restrain Th17 Immunity in a Stage-Specific Manner.

T cell factor 1 (TCF-1) is expressed in both developing and mature T cells and has been shown to restrain mature T cell-mediated Th17 responses by inhibiting IL-17 expression. However, it is not clear when TCF-1 is required in vivo to restrain the magnitude of peripheral Th17 responses and what the molecular mechanisms responsible for TCF-1-regulated IL-17 gene expression are. In this study, we showed that conditional deletion of TCF-1 at the early but not later CD4+CD8+ double-positive stage in mice enhanced Th17 differentiation and aggravated experimental autoimmune encephalomyelitis, which correlates with abnormally high IL-17 expression. Expression of TCF-1 in TCF-1-deficient thymocytes but not TCF-1-deficient Th17 cells inhibited IL-17 expression. TCF-1 binds to IL-17 promoter regions, and deletion of two TCF-1 binding sites relieves TCF-1-mediated inhibition of IL-17 promoter activity. Lastly, wild-type TCF-1, but not a TCF-1 mutant that has no intrinsic histone deacetylase activity, was able to inhibit IL-17 expression in TCF-1 deficient mouse thymocytes. Thus, our study demonstrates the requirement of TCF-1 in vivo at stages earlier than double-positive cells to restrain peripheral Th17 immunity by directly binding and inhibiting IL-17 promoter in its intrinsic histone deacetylase-dependent manner.

PRMT1 Plays a Critical Role in Th17 Differentiation by Regulating Reciprocal Recruitment of STAT3 and STAT5.

Th17 cells are a class of Th cells that secrete IL-17 and mediate pathogenic immunity responsible for autoimmunity including experimental autoimmune encephalomyelitis, a murine model of multiple sclerosis. Retinoic acid-related orphan receptor γ t (RORγt) is the critical transcription factor that controls the differentiation of Th17 cells. However, little is known about the transcriptional cofactors for RORγt in the regulation of Th17 differentiation. In this study, we demonstrate that protein arginine N-methyltransferase 1 (PRMT1) associates with RORγt and regulates mouse Th17 differentiation. Overexpression of PRMT1 promoted Th17 differentiation, whereas inactivation or knockdown of PRMT1 decreased Th17 differentiation while expanding Foxp3+ regulatory T cells. Consistently, pharmacological inhibition of PRMT1 impaired the generation of Th17 cells and prevented induction of experimental autoimmune encephalomyelitis in mice. Mechanistically, PRMT1-dependent modification of asymmetric histone 4 arginine 3 dimethylation is required to stabilize the stimulatory STAT3 to displace the inhibitory STAT5 at IL-17 locus, resulting in the activation of IL-17 gene. Furthermore, PRMT1-facilitated recruitment of STAT3 overcame the inhibition of Th17 differentiation exerted by IL-2-induced STAT5 activation. PRMT1 thus regulates Th17 differentiation by controlling the reciprocal recruitment of STAT3 and STAT5. Our study thus reveals PRMT1 as a novel target for alleviating Th17-mediated autoimmunity by decreasing RORγt-dependent generation of pathogenic Th17 cells.

Inter-clinician eConsults without programmatic incentives or requirements: a qualitative study of primary care provider perspectives.

BACKGROUND: Inter-clinician electronic consultation (eConsult) programmes are becoming more widespread in the USA as health care systems seek innovative ways of improving specialty access. Existing studies examine models with programmatic incentives or requirements for primary care providers (PCPs) to participate. OBJECTIVE: We aimed to examine PCP perspectives on eConsults in a system with no programmatic incentive or requirement for PCPs to use eConsults. METHODS: We conducted seven focus groups with 41 PCPs at a safety-net community teaching health care system in Eastern Massachusetts, USA. RESULTS: Focus groups revealed that eConsults improved PCP experience by enabling patient-centred care and enhanced PCP education. However, increased workload and variations in communication patterns added challenges for PCPs. Patients were perceived as receiving timelier and more convenient care. Timelier care combined with direct documentation in the patient record was perceived as improving patient safety. Although cost implications were less clear, PCPs perceived costs as being lowered through fewer unnecessary visits and laboratories. CONCLUSIONS: Our findings suggest that eConsult systems with no programmatic incentives or requirements for PCPs have the potential to improve care.

Visual Saliency Detection for Over-Temperature Regions in 3D Space via Dual-Source Images.

To allow mobile robots to visually observe the temperature of equipment in complex industrial environments and work on temperature anomalies in time, it is necessary to accurately find the coordinates of temperature anomalies and obtain information on the surrounding obstacles. This paper proposes a visual saliency detection method for hypertemperature in three-dimensional space through dual-source images. The key novelty of this method is that it can achieve accurate salient object detection without relying on high-performance hardware equipment. First, the redundant point clouds are removed through adaptive sampling to reduce the computational memory. Second, the original images are merged with infrared images and the dense point clouds are surface-mapped to visually display the temperature of the reconstructed surface and use infrared imaging characteristics to detect the plane coordinates of temperature anomalies. Finally, transformation mapping is coordinated according to the pose relationship to obtain the spatial position. Experimental results show that this method not only displays the temperature of the device directly but also accurately obtains the spatial coordinates of the heat source without relying on a high-performance computing platform.

Regulation of Th17 Differentiation by IKKα-Dependent and -Independent Phosphorylation of RORγt.

Transcription factor retinoid acid-related orphan receptor (ROR)γt transcriptionally regulates the genes required for differentiation of Th17 cells that mediate both protective and pathogenic immunity. However, little is known about the function of posttranslational modifications in the regulation of RORγt activity. Mass spectrometric analysis of immunoprecipitated RORγt from Th17 cells identified multiple phosphorylation sites. Systematic mutation analysis of the identified phosphorylation sites found that phosphorylation of S376 enhances whereas phosphorylation of S484 inhibits Th17 differentiation. IκB kinase (IKK)α binds and phosphorylates RORγt at S376 but not S484. Knockdown of IKKα, dominant-negative IKKα, and RORγt mutants incapable of interacting with IKKα all decrease Th17 differentiation. Furthermore, nonphosophorylatable RORγt mutant (S376A) impairs whereas phosphomimetic mutant (S376E) stimulates Th17 differentiation independent of IKKα. Therefore, IKKα-dependent phosphorylation of S376 stimulated whereas IKKα-independent phosphorylation of S484 inhibited RORγt function in Th17 differentiation.

Fine-Tuning of the Kaposi's Sarcoma-Associated Herpesvirus Life Cycle in Neighboring Cells through the RTA-JAG1-Notch Pathway.

Kaposi's sarcoma (KS)-associated herpesvirus (KSHV) is an oncogenic pathogen that displays latent and lytic life cycles. In KS lesions, infiltrated immune cells, secreted viral and/or cellular cytokines, and hypoxia orchestrate a chronic pro-lytic microenvironment that can promote KSHV reactivation. However, only a small subset of viruses spontaneously undergoes lytic replication in this pro-lytic microenvironment while the majority remains in latency. Here, we show that the expression of the Notch ligand JAG1 is induced by KSHV-encoded replication and transcription activator (RTA) during reactivation. JAG1 up-regulation activates Notch signaling in neighboring cells and prevents viral lytic replication. The suppression of JAG1 and Notch1 with inhibitors or small interfering RNA promotes lytic replication in the presence of RTA induction or under conditions of hypoxia. The underlying mechanism involves the Notch downstream effector hairy and enhancer of split 1 (Hes1), which directly binds lytic gene promoters and attenuates viral lytic gene expression. RTA interacts with lymphoid enhancer-binding factor 1 (LEF1), disrupts LEF1/Groucho/TLE suppressive complexes and releases LEF1 to activate JAG1 expression. Taken together, our results suggest that cells with viral lytic replication can inhibit KSHV reactivation in neighboring cells through an RTA-JAG1-Notch pathway. These data provide insight into the mechanism by which the virus maintains the balance between lytic and latent infection in the pro-lytic tumor microenvironment.

Ubiquitination of RORγt at Lysine 446 Limits Th17 Differentiation by Controlling Coactivator Recruitment.

The transcription factor retinoid acid-related orphan receptor γ t (RORγt) directs the differentiation of Th17 cells. Th17 cells mediate pathological immune responses responsible for autoimmune diseases, including psoriasis and multiple sclerosis. Previous studies focused on RORγt target genes and their function in Th17 differentiation. In this study, we assessed posttranscriptional regulation of RORγt and identified a functional ubiquitination site, K446. Mutation of K446 to arginine to prevent ubiquitination greatly enhanced recruitment of steroid receptor coactivator 1 (SRC1), a coactivator critical for RORγt activity. Correspondingly, the K446 to arginine mutation potentiated Th17 differentiation. We also showed that ubiquitin-specific protease (USP)15 interacted with RORγt, removed ubiquitin from K446, and stimulated RORγt activity by enhancing coactivator SRC1 recruitment. Knockdown of USP15 or expression of inactive USP15 impaired Th17 differentiation, suggesting a positive role for USP15-mediated deubiquitination of RORγt in Th17 differentiation. Therefore, ubiquitination of K446 limits RORγt-mediated Th17 differentiation by inhibiting the recruitment of coactivator SRC1. Our study will inform the development of treatments that target RORγt ubiquitination pathways to limit Th17-mediated autoimmunity.

Oncogenic herpesvirus KSHV Hijacks BMP-Smad1-Id signaling to promote tumorigenesis.

Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiological agent of Kaposi's sarcoma (KS), a malignancy commonly found in AIDS patients. Whether KS is a true neoplasm or hyperplasia has been a subject of intensive debate until recently when KSHV is unequivocally shown to efficiently infect, immortalize and transform rat primary mesenchymal precursor cells (MM). Moreover, KSHV-transformed MM cells (KMM) efficiently induce tumors with hallmark features of KS when inoculated into nude mice. Here, we showed Smad1 as a novel binding protein of KSHV latency-associated nuclear antigen (LANA). LANA interacted with and sustained BMP-activated p-Smad1 in the nucleus and enhanced its loading on the Id promoters. As a result, Ids were significantly up-regulated in KMM cells and abundantly expressed in human KS lesions. Strikingly, genetic and chemical inhibition of the BMP-Smad1-Id pathway blocked the oncogenic phenotype of KSHV-transformed cells in vitro and in vivo. These findings illustrate a novel mechanism by which a tumor virus hijacks and converts a developmental pathway into an indispensable oncogenic pathway for tumorigenesis. Importantly, our results demonstrate the efficacy of targeting the BMP-Smad1-Id pathway for inhibiting the growth of KSHV-induced tumors, and therefore identify the BMP pathway as a promising therapeutic target for KS.

Low iodine diet in differentiated thyroid cancer: a review.

Radioactive iodine (RAI) ablation is a beneficial, adjuvant therapy for the management of differentiated thyroid cancer (DTC) after thyroidectomy. The goal of RAI is to destroy remnant thyroid and microscopic cancerous tissue. Radioactive iodine uptake is enhanced by elevating TSH levels and initiating a low iodine diet (LID) prior to ablation. An ideal LID should preferably not exceed 50 mcg/day of dietary iodine for 1-2 weeks, although the duration may be shortened to a week with a structured patient education programme. A pre-ablation spot urinary iodine concentration (UIC) of <100 mcg/l and/or a urinary iodine to creatinine ratio (UICR) of <100 mcg/gCr would support an adequate LID preparation. Hyponatraemia, most likely due to iatrogenic hypothyroidism, is a potential side effect associated with LID and occurs during and a few days after the LID. Although the overall incidence of hyponatraemia is low, patients at high risk (older age, female sex, use of thiazide diuretics) may benefit from serum sodium monitoring. The existing evidence on the impact of LID on RAI ablation has been largely inconsistent due to retrospective study designs and the lack of an objective measurement of urinary iodine levels. Future large prospective randomized control trials are needed to elucidate and confirm the crucial role of LID in achieving successful RAI ablation and greater disease-free survival in DTC.

Mycophenolic Acid-Induced Developmental Defects in Zebrafish Embryos.

With the increasing use of mycophenolic acid (MPA) in solid organ transplantation, some clinical studies indicate that it is also a human teratogen. However, it is unknown by which mechanism MPA acts as a teratogen. Mycophenolic acid was a selective blocker of de novo purine synthesis, and its immunosuppressive effect is mediated by the inhibition of inosine monophosphate dehydrogenase, which could be a target for MPA-induced toxicity as well. The aim of our study was to examine the direct influence of MPA exposure on zebrafish (Danio rerio) embryos. Morphological defects including tail curvature and severe pericardial edema in zebrafish embryos caused by MPA (3.7-11.1 µmol/L) were found in a dose-dependent manner. The teratogenic index (25% lethal concentration value (LC25)/no observed adverse effect level ratio) was 16, which indicated MPA as a teratogen. Quantitative polymerase chain reaction analysis revealed that the expression level of impdh1b and impdh2 was significantly reduced by MPA treatment at 8 µmol/L (equals to LC25 level). All the toxic effects could be partially reversed by the addition of 33.3 µmol/L guanosine. Our results indicated that MPA impairs the development of zebrafish embryos via inhibition of impdh activity, which subsequently caused a guanosine nucleotide depletion in vivo.

NF-κB activation coordinated by IKKß and IKKε enables latent infection of Kaposi's sarcoma-associated herpesvirus.

All herpesviruses share a remarkable propensity to establish latent infection. Human Kaposi's sarcoma-associated herpesvirus (KSHV) effectively enters latency after de novo infection, suggesting that KSHV has evolved with strategies to facilitate latent infection. NF-κB activation is imperative for latent infection of gammaherpesviruses. However, how NF-κB is activated during de novo herpesvirus infection is not fully understood. Here, we report that KSHV infection activates the inhibitor of κB kinase ß (IKKß) and the IKK-related kinase epsilon (IKKε) to enable host NF-κB activation and KSHV latent infection. Specifically, KSHV infection activated IKKß and IKKε that were crucial for latent infection. Knockdown of IKKß and IKKε caused aberrant lytic gene expression and impaired KSHV latent infection. Biochemical and genetic experiments identified RelA as a key player downstream of IKKß and IKKε. Remarkably, IKKß and IKKε were essential for phosphorylation of S(536) and S(468) of RelA, respectively. Phosphorylation of RelA S(536) was required for phosphorylation of S(468), which activated NF-κB and promoted KSHV latent infection. Expression of the phosphorylation-resistant RelA S(536)A increased KSHV lytic gene expression and impaired latent infection. Our findings uncover a scheme wherein NF-κB activation is coordinated by IKKß and IKKε, which sequentially phosphorylate RelA in a site-specific manner to enable latent infection after KSHV de novo infection.