Jun Li
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Publication
Journal: Journal of Immunology
April/27/2006
Abstract
Translocation of bacteria across the intestinal barrier is important in the pathogenesis of systemic sepsis, although the mechanisms by which bacterial translocation occurs remain largely unknown. We hypothesized that bacterial translocation across the intact barrier occurs after internalization of the bacteria by enterocytes in a process resembling phagocytosis and that TLR4 is required for this process. We now show that FcgammaRIIa-transfected enterocytes can internalize IgG-opsonized erythrocytes into actin-rich cups, confirming that these enterocytes have the molecular machinery required for phagocytosis. We further show that enterocytes can internalize Escherichia coli into phagosomes, that the bacteria remain viable intracellularly, and that TLR4 is required for this process to occur. TLR4 signaling was found to be necessary and sufficient for phagocytosis by epithelial cells, because IEC-6 intestinal epithelial cells were able to internalize LPS-coated, but not uncoated, latex particles and because MD2/TLR4-transfected human endothelial kidney (HEK)-293 cells acquired the capacity to internalize E. coli, whereas nontransfected HEK-293 cells and HEK-293 cells transfected with dominant-negative TLR4 bearing a P712H mutation did not. LPS did not induce membrane ruffling or macropinocytosis in enterocytes, excluding their role in bacterial internalization. Strikingly, the internalization of Gram-negative bacteria into enterocytes in vivo and the translocation of bacteria across the intestinal epithelium to mesenteric lymph nodes were significantly greater in wild-type mice as compared with mice having mutations in TLR4. These data suggest a novel mechanism by which bacterial translocation occurs and suggest a critical role for TLR4 in the phagocytosis of bacteria by enterocytes in this process.
Publication
Journal: Nature Methods
December/25/2013
Publication
Journal: Genes and Development
February/25/2009
Abstract
Intermittent administration of PTH stimulates bone formation, but the precise mechanisms responsible for PTH responses in osteoblasts are only incompletely understood. Here we show that binding of PTH to its receptor PTH1R induced association of LRP6, a coreceptor of Wnt, with PTH1R. The formation of the ternary complex containing PTH, PTH1R, and LRP6 promoted rapid phosphorylation of LRP6, which resulted in the recruitment of axin to LRP6, and stabilization of beta-catenin. Activation of PKA is essential for PTH-induced beta-catenin stabilization, but not for Wnt signaling. In vivo studies confirmed that PTH treatment led to phosphorylation of LRP6 and an increase in amount of beta-catenin in osteoblasts with a concurrent increase in bone formation in rat. Thus, LRP6 coreceptor is a key element of the PTH signaling that regulates osteoblast activity.
Publication
Journal: Genome Biology
September/28/2010
Abstract
After mapping, RNA-Seq data can be summarized by a sequence of read counts commonly modeled as Poisson variables with constant rates along each transcript, which actually fit data poorly. We suggest using variable rates for different positions, and propose two models to predict these rates based on local sequences. These models explain more than 50% of the variations and can lead to improved estimates of gene and isoform expressions for both Illumina and Applied Biosystems data.
Publication
Journal: Biostatistics
November/4/2012
Abstract
We discuss the identification of genes that are associated with an outcome in RNA sequencing and other sequence-based comparative genomic experiments. RNA-sequencing data take the form of counts, so models based on the Gaussian distribution are unsuitable. Moreover, normalization is challenging because different sequencing experiments may generate quite different total numbers of reads. To overcome these difficulties, we use a log-linear model with a new approach to normalization. We derive a novel procedure to estimate the false discovery rate (FDR). Our method can be applied to data with quantitative, two-class, or multiple-class outcomes, and the computation is fast even for large data sets. We study the accuracy of our approaches for significance calculation and FDR estimation, and we demonstrate that our method has potential advantages over existing methods that are based on a Poisson or negative binomial model. In summary, this work provides a pipeline for the significance analysis of sequencing data.
Publication
Journal: Acta Pharmacologica Sinica
August/30/2015
Abstract
Androgens and androgen receptors (AR) play a pivotal role in expression of the male phenotype. Several diseases, such as androgen insensitivity syndrome (AIS) and prostate cancer, are associated with alterations in AR functions. Indeed, androgen blockade by drugs that prevent the production of androgens and/or block the action of the AR inhibits prostate cancer growth. However, resistance to these drugs often occurs after 2-3 years as the patients develop castration-resistant prostate cancer (CRPC). In CRPC, a functional AR remains a key regulator. Early studies focused on the functional domains of the AR and its crucial role in the pathology. The elucidation of the structures of the AR DNA binding domain (DBD) and ligand binding domain (LBD) provides a new framework for understanding the functions of this receptor and leads to the development of rational drug design for the treatment of prostate cancer. An overview of androgen receptor structure and activity, its actions in prostate cancer, and how structural information and high-throughput screening have been or can be used for drug discovery are provided herein.
Publication
Journal: Cancer Letters
April/26/2016
Abstract
Multidrug resistance (MDR) is a serious phenomenon employed by cancer cells which hampers the success of cancer pharmacotherapy. One of the common mechanisms of MDR is the overexpression of ATP-binding cassette (ABC) efflux transporters in cancer cells such as P-glycoprotein (P-gp/ABCB1), multidrug resistance-associated protein 2 (MRP2/ABCC2), and breast cancer resistance protein (BCRP/ABCG2) that limits the prolonged and effective use of chemotherapeutic drugs. Researchers have found that developing inhibitors of ABC efflux transporters as chemosensitizers could overcome MDR. But the clinical trials have shown that most of these chemosensitizers are merely toxic and only show limited or no benefits to cancer patients, thus new inhibitors are being explored. Recent findings also suggest that efflux pumps of the ABC transporter family are subject to epigenetic gene regulation. In this review, we summarize recent findings of the role of ABC efflux transporters in MDR.
Publication
Journal: Nature Communications
March/31/2014
Abstract
Sorghum is a food and feed cereal crop adapted to heat and drought and a staple for 500 million of the world's poorest people. Its small diploid genome and phenotypic diversity make it an ideal C4 grass model as a complement to C3 rice. Here we present high coverage (16-45 × ) resequenced genomes of 44 sorghum lines representing the primary gene pool and spanning dimensions of geographic origin, end-use and taxonomic group. We also report the first resequenced genome of S. propinquum, identifying 8 M high-quality SNPs, 1.9 M indels and specific gene loss and gain events in S. bicolor. We observe strong racial structure and a complex domestication history involving at least two distinct domestication events. These assembled genomes enable the leveraging of existing cereal functional genomics data against the novel diversity available in sorghum, providing an unmatched resource for the genetic improvement of sorghum and other grass species.
Publication
Journal: Nature Protocols
October/25/2015
Abstract
Targeted genome editing nucleases, such as zinc-finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs), are powerful tools for understanding gene function and for developing valuable new traits in plants. The clustered regularly interspersed short palindromic repeats (CRISPR)/Cas system has recently emerged as an alternative nuclease-based method for efficient and versatile genome engineering. In this system, only the 20-nt targeting sequence within the single-guide RNA (sgRNA) needs to be changed to target different genes. The simplicity of the cloning strategy and the few limitations on potential target sites make the CRISPR/Cas system very appealing. Here we describe a stepwise protocol for the selection of target sites, as well as the design, construction, verification and use of sgRNAs for sequence-specific CRISPR/Cas-mediated mutagenesis and gene targeting in rice and wheat. The CRISPR/Cas system provides a straightforward method for rapid gene targeting within 1-2 weeks in protoplasts, and mutated rice plants can be generated within 13-17 weeks.
Publication
Journal: Clinical Microbiology Reviews
April/13/2003
Abstract
Echinococcosis is a cosmopolitan zoonosis caused by adult or larval stages of cestodes belonging to the genus Echinococcus (family Taeniidae). The two major species of medical and public health importance are Echinococcus granulosus and E. multilocularis, which cause cystic echinococcosis (CE) and alveolar echinococcosis (AE), respectively. Both CE and AE are both serious diseases, the latter especially so, with a high fatality rate and poor prognosis if managed inappropriately. This review discusses new concepts and approaches in the immunology and diagnosis of CE, but comparative reference has also been made to AE infection and to earlier pivotal studies of both diseases. The review considers immunity to infection in the intermediate and definitive hosts, innate resistance, evasion of the immune system, and vaccination of intermediate and definitive hosts, and it particularly emphasizes procedures for diagnosis of CE and AE, including the value of immunodiagnostic approaches. There is also discussion of the new advances in recombinant and related DNA technologies, especially application of PCR, that are providing powerful tools in the fields of vaccinology and molecular diagnosis of echinococcosis.
Publication
Journal: Nature Immunology
December/10/2006
Abstract
The present paradigm dictates that phagocytosis is accomplished mainly by 'professional' phagocytes (such as macrophages and monocytes), whereas B cells lack phagocytic capabilities. Here we demonstrate that B cells from teleost fish have potent in vitro and in vivo phagocytic activities. Particle uptake by B cells induced activation of 'downstream' degradative pathways, leading to 'phagolysosome' formation and intracellular killing of ingested microbes. Those results indicate a previously unknown function for B cells in the innate immunity of these primitive animals. A considerable proportion of Xenopus laevis B cells were also phagocytic. Our findings support the idea that B cells evolved from an ancestral phagocytic cell type and provide an evolutionary framework for understanding the close relationship between mammalian B lymphocytes and macrophages.
Publication
Journal: Nature Communications
October/25/2015
Abstract
Prognostic genes are key molecules informative for cancer prognosis and treatment. Previous studies have focused on the properties of individual prognostic genes, but have lacked a global view of their system-level properties. Here we examined their properties in gene co-expression networks for four cancer types using data from 'The Cancer Genome Atlas'. We found that prognostic mRNA genes tend not to be hub genes (genes with an extremely high connectivity), and this pattern is unique to the corresponding cancer-type-specific network. In contrast, the prognostic genes are enriched in modules (a group of highly interconnected genes), especially in module genes conserved across different cancer co-expression networks. The target genes of prognostic miRNA genes show similar patterns. We identified the modules enriched in various prognostic genes, some of which show cross-tumour conservation. Given the cancer types surveyed, our study presents a view of emergent properties of prognostic genes.
Publication
Journal: Nature Genetics
March/25/2013
Abstract
Central corneal thickness (CCT) is associated with eye conditions including keratoconus and glaucoma. We performed a meta-analysis on >20,000 individuals in European and Asian populations that identified 16 new loci associated with CCT at genome-wide significance (P < 5 × 10(-8)). We further showed that 2 CCT-associated loci, FOXO1 and FNDC3B, conferred relatively large risks for keratoconus in 2 cohorts with 874 cases and 6,085 controls (rs2721051 near FOXO1 had odds ratio (OR) = 1.62, 95% confidence interval (CI) = 1.4-1.88, P = 2.7 × 10(-10), and rs4894535 in FNDC3B had OR = 1.47, 95% CI = 1.29-1.68, P = 4.9 × 10(-9)). FNDC3B was also associated with primary open-angle glaucoma (P = 5.6 × 10(-4); tested in 3 cohorts with 2,979 cases and 7,399 controls). Further analyses implicate the collagen and extracellular matrix pathways in the regulation of CCT.
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Publication
Journal: Journal of Immunology
December/21/2009
Abstract
Molecular danger signals attract neutrophilic granulocytes (polymorphonuclear leukocytes (PMNs)) to sites of infection. The G protein-coupled receptor (GPR) 43 recognizes propionate and butyrate and is abundantly expressed on PMNs. The functional role of GPR43 activation for in vivo orchestration of immune response is unclear. We examined dextrane sodium sulfate (DSS)-induced acute and chronic intestinal inflammatory response in wild-type and Gpr43-deficient mice. The severity of colonic inflammation was assessed by clinical signs, histological scoring, and cytokine production. Chemotaxis of wild-type and Gpr43-deficient PMNs was assessed through transwell cell chemotactic assay. A reduced invasion of PMNs and increased mortality due to septic complications were observed in acute DSS colitis. In chronic DSS colitis, Gpr43(-/-) animals showed diminished PMN intestinal migration, but protection against inflammatory tissue destruction. No significant difference in PMN migration and cytokine secretion was detected in a sterile inflammatory model. Ex vivo experiments show that GPR43-induced migration is dependent on activation of the protein kinase p38alpha, and that this signal acts in cooperation with the chemotactic cytokine keratinocyte chemoattractant. Interestingly, shedding of L-selectin in response to propionate and butyrate was compromised in Gpr43(-/-) mice. These results indicate a critical role for GPR43-mediated recruitment of PMNs in containing intestinal bacterial translocation, yet also emphasize the bipotential role of PMNs in mediating tissue destruction in chronic intestinal inflammation.
Publication
Journal: FASEB Journal
October/4/2006
Abstract
Embryonic stem (ES) cells possess the ability to renew themselves while maintaining the capacity to differentiate into virtually all cell types of the body. Current evidence suggests that ES cells maintain their pluripotent state by expressing a battery of transcription factors including Oct4 and Nanog. However, little is known about how ES cells maintain the expression of these pluripotent factors in ES cells. Here we present evidence that Oct4, Nanog, and FoxD3 form a negative feedback loop to maintain their expression in pluripotent ES cells. First, Oct4 maintains Nanog activity by directly activating its promoter at sub-steady-state concentration but repressing it at or above steady-state levels. On the other hand, FoxD3 behaves as a positive activator of Nanog to counter the repressive effect of Oct4. The expression of Oct4 is activated by FoxD3 and Nanog but repressed by Oct4 itself, thus, exerting an important negative feedback loop to limit its own activity. Indeed, overexpression of either FoxD3 or Nanog in ES cells failed to increase the concentration of Oct4 beyond the steady-state concentration, whereas knocking down either FoxD3 or Nanog reduces the expression of Oct4 in ES cells. Finally, overexpression of Oct4 or Nanog failed to compensate the loss of Nanog or Oct4, respectively, suggesting that both are required for ES self-renewal and pluripotency. Our results suggest the FoxD3-Nanog-Oct4 loop anchors an interdependent network of transcription factors that regulate stem cell pluripotency.
Publication
Journal: Journal of Virology
March/30/2008
Abstract
Coronaviruses (CoVs) can infect humans and multiple species of animals, causing a wide spectrum of diseases. The coronavirus main protease (M(pro)), which plays a pivotal role in viral gene expression and replication through the proteolytic processing of replicase polyproteins, is an attractive target for anti-CoV drug design. In this study, the crystal structures of infectious bronchitis virus (IBV) M(pro) and a severe acute respiratory syndrome CoV (SARS-CoV) M(pro) mutant (H41A), in complex with an N-terminal autocleavage substrate, were individually determined to elucidate the structural flexibility and substrate binding of M(pro). A monomeric form of IBV M(pro) was identified for the first time in CoV M(pro) structures. A comparison of these two structures to other available M(pro) structures provides new insights for the design of substrate-based inhibitors targeting CoV M(pro)s. Furthermore, a Michael acceptor inhibitor (named N3) was cocrystallized with IBV M(pro) and was found to demonstrate in vitro inactivation of IBV M(pro) and potent antiviral activity against IBV in chicken embryos. This provides a feasible animal model for designing wide-spectrum inhibitors against CoV-associated diseases. The structure-based optimization of N3 has yielded two more efficacious lead compounds, N27 and H16, with potent inhibition against SARS-CoV M(pro).
Publication
Journal: The Lancet Neurology
July/29/2008
Abstract
West Nile virus is a mosquito-borne flavivirus originally isolated in 1937 from the blood of a febrile woman in the West Nile province of Uganda. The virus is widely distributed in Africa, Europe, Australia, and Asia, and, since 1999, it has spread rapidly throughout the western hemisphere, including the USA, Canada, Mexico, and the Caribbean and into parts of Central and South America. Before 1994, outbreaks of West Nile virus were sporadic and occurred primarily in the Mediterranean region, Africa, and east Europe. Since 1994, outbreaks have occurred with a higher incidence of severe human disease, particularly affecting the nervous system. In North America, the virus has caused meningitis, encephalitis, and poliomyelitis, resulting in significant morbidity and mortality. The goal of this Review is to highlight recent advances in our understanding of West Nile virus virology, ecology, clinical disease, diagnosis, and development of potential vaccines and antiviral therapies.
Publication
Journal: MMWR. Surveillance summaries : Morbidity and mortality weekly report. Surveillance summaries / CDC
February/23/2012
Abstract
OBJECTIVE
Approximately 12 million people are living with cancer in the United States. Limited information is available on national and state assessments of health behaviors among cancer survivors. Using data from the Behavioral Risk Factor Surveillance System (BRFSS), this report provides a descriptive state-level assessment of demographic characteristics and health behaviors among cancer survivors aged ≥18 years.
METHODS
2009
METHODS
BRFSS is an ongoing, state-based, random-digit-dialed telephone survey of the noninstitutionalized U.S. population aged ≥18 years. BRFSS collects information on health risk behaviors and use of preventive health services related to leading causes of death and morbidity. In 2009, BRFSS added questions about previous cancer diagnoses to the core module. The 2009 BRFSS also included an optional cancer survivorship module that assessed cancer treatment history and health insurance coverage for cancer survivors. In 2009, all 50 states, the District of Columbia, Guam, Puerto Rico, and the U.S. Virgin Islands administered the core cancer survivorship questions, and 10 states administered the optional supplemental cancer survivorship module. Five states added questions on mammography and Papanicolaou (Pap) test use, eight states included questions on colorectal screening, and five states included questions on prostate cancer screening.
RESULTS
An estimated 7.2% of the U.S. general population aged ≥18 years reported having received a previous cancer diagnosis (excluding nonmelanoma skin cancer). A total of 78.8% of cancer survivors were aged ≥50 years, and 39.2% had received a diagnosis of cancer >10 years previously. A total of 57.8% reported receiving an influenza vaccination during the previous year, and 48.3% reported ever receiving a pneumococcal vaccination. At the time of the interview, 6.8% of cancer survivors had no health insurance, and 12% had been denied health insurance, life insurance, or both because of their cancer diagnosis. The prevalence of cardiovascular disease was higher among male cancer survivors (23.4%) than female cancer survivors (14.3%), as was the prevalence of diabetes (19.6% and 14.7%, respectively). Overall, approximately 15.1% of cancer survivors were current cigarette smokers, 27.5% were obese, and 31.5% had not engaged in any leisure-time physical activity during the past 30 days. Demographic characteristics and health behaviors among cancer survivors varied substantially by state.
CONCLUSIONS
Health behaviors and preventive health care practices among cancer survivors vary by state and demographic characteristics. A large proportion of cancer survivors have comorbid conditions, currently smoke, do not participate in any leisure-time physical activity, and are obese. In addition, many are not receiving recommended preventive care, including cancer screening and influenza and pneumococcal vaccinations.
CONCLUSIONS
Health-care providers and patients should be aware of the importance of preventive care, smoking cessation, regular physical activity, and maintaining a healthy weight for cancer survivors. The findings in this report can help public health practitioners, researchers, and comprehensive cancer control programs evaluate the effectiveness of program activities for cancer survivors, assess the needs of cancer survivors at the state level, and allocate appropriate resources to address those needs.
Publication
Journal: Cancer Cell
January/17/2016
Abstract
Adenosine-to-inosine (A-to-I) RNA editing is a widespread post-transcriptional mechanism, but its genomic landscape and clinical relevance in cancer have not been investigated systematically. We characterized the global A-to-I RNA editing profiles of 6,236 patient samples of 17 cancer types from The Cancer Genome Atlas and revealed a striking diversity of altered RNA-editing patterns in tumors relative to normal tissues. We identified an appreciable number of clinically relevant editing events, many of which are in noncoding regions. We experimentally demonstrated the effects of several cross-tumor nonsynonymous RNA editing events on cell viability and provide the evidence that RNA editing could selectively affect drug sensitivity. These results highlight RNA editing as an exciting theme for investigating cancer mechanisms, biomarkers, and treatments.
Publication
Journal: Nature
October/28/2013
Abstract
Folate receptors (FRα, FRβ and FRγ) are cysteine-rich cell-surface glycoproteins that bind folate with high affinity to mediate cellular uptake of folate. Although expressed at very low levels in most tissues, folate receptors, especially FRα, are expressed at high levels in numerous cancers to meet the folate demand of rapidly dividing cells under low folate conditions. The folate dependency of many tumours has been therapeutically and diagnostically exploited by administration of anti-FRα antibodies, high-affinity antifolates, folate-based imaging agents and folate-conjugated drugs and toxins. To understand how folate binds its receptors, we determined the crystal structure of human FRα in complex with folic acid at 2.8 Å resolution. FRα has a globular structure stabilized by eight disulphide bonds and contains a deep open folate-binding pocket comprised of residues that are conserved in all receptor subtypes. The folate pteroate moiety is buried inside the receptor, whereas its glutamate moiety is solvent-exposed and sticks out of the pocket entrance, allowing it to be conjugated to drugs without adversely affecting FRα binding. The extensive interactions between the receptor and ligand readily explain the high folate-binding affinity of folate receptors and provide a template for designing more specific drugs targeting the folate receptor system.
Publication
Journal: Cell
October/22/2002
Abstract
Hop is a small, divergent homeodomain protein that lacks certain conserved residues required for DNA binding. Hop gene expression initiates early in cardiogenesis and continues in cardiomyocytes throughout embryonic and postnatal development. Genetic and biochemical data indicate that Hop functions directly downstream of Nkx2-5. Inactivation of Hop in mice by homologous recombination results in a partially penetrant embryonic lethal phenotype with severe developmental cardiac defects involving the myocardium. Inhibition of Hop activity in zebrafish embryos likewise disrupts cardiac development and results in severely impaired cardiac function. Hop physically interacts with serum response factor (SRF) and inhibits activation of SRF-dependent transcription by inhibiting SRF binding to DNA. Hop encodes an unusual homeodomain protein that modulates SRF-dependent cardiac-specific gene expression and cardiac development.
Publication
Journal: Accounts of Chemical Research
April/7/2014
Abstract
Supported metal nanostructures are the most widely used type of heterogeneous catalyst in industrial processes. The size of metal particles is a key factor in determining the performance of such catalysts. In particular, because low-coordinated metal atoms often function as the catalytically active sites, the specific activity per metal atom usually increases with decreasing size of the metal particles. However, the surface free energy of metals increases significantly with decreasing particle size, promoting aggregation of small clusters. Using an appropriate support material that strongly interacts with the metal species prevents this aggregation, creating stable, finely dispersed metal clusters with a high catalytic activity, an approach industry has used for a long time. Nevertheless, practical supported metal catalysts are inhomogeneous and usually consist of a mixture of sizes from nanoparticles to subnanometer clusters. Such heterogeneity not only reduces the metal atom efficiency but also frequently leads to undesired side reactions. It also makes it extremely difficult, if not impossible, to uniquely identify and control the active sites of interest. The ultimate small-size limit for metal particles is the single-atom catalyst (SAC), which contains isolated metal atoms singly dispersed on supports. SACs maximize the efficiency of metal atom use, which is particularly important for supported noble metal catalysts. Moreover, with well-defined and uniform single-atom dispersion, SACs offer great potential for achieving high activity and selectivity. In this Account, we highlight recent advances in preparation, characterization, and catalytic performance of SACs, with a focus on single atoms anchored to metal oxides, metal surfaces, and graphene. We discuss experimental and theoretical studies for a variety of reactions, including oxidation, water gas shift, and hydrogenation. We describe advances in understanding the spatial arrangements and electronic properties of single atoms, as well as their interactions with the support. Single metal atoms on support surfaces provide a unique opportunity to tune active sites and optimize the activity, selectivity, and stability of heterogeneous catalysts, offering the potential for applications in a variety of industrial chemical reactions.
Publication
Journal: Carcinogenesis
July/31/2013
Abstract
Invasion of hepatocellular carcinoma (HCC) cells is a leading cause of intrahepatic dissemination and metastasis. Autophagy is considered to be an important mediator in the invasion of cancer cells. However, the precise contribution of autophagy to cancer cell invasion and underlying mechanisms remain unclear. Autophagy was induced in HepG2 and BEL7402 cells by starvation in Hank's balanced salt solution. Induction of autophagy inhibited the expression of epithelial markers and induced expression of mesenchymal markers as well as matrix metalloproteinase-9 stimulating cell invasion. Starvation-induced autophagy promoted the expression of epithelial-mesenchymal transition (EMT) markers and invasion in HepG2 and BEL7402 cells through a transforming growth factor-beta (TGF-β)/Smad3 signaling-dependent manner. The small interfering RNAs (siRNAs) for Atg3 or Atg7 and chloroquine inhibited autophagy of HepG2 and BEL7402 cells during starvation, resulting in suppression of EMT and diminished invasiveness of HCC cells. Administration of SIS3 also attenuated EMT and invasion of HepG2 and BEL7402 cells during starvation. Recombinant TGF-β1 was capable of rescuing EMT and invasion that was inhibited by siRNA for Atg3 and 7 in HepG2 and BEL7402 cells under starvation. These findings suggest that autophagy is critical for the invasion of HCC cells through the induction of EMT and that activation of TGF-β/Smad3-dependent signaling plays a key role in regulating autophagy-induced EMT. Inhibition of autophagy may represent a novel target for therapeutic interventions.
Publication
Journal: Journal of Immunology
June/30/2010
Abstract
Inhibiting signal transduction induced by inflammatory cytokines offers a new approach for the treatment of autoimmune diseases such as rheumatoid arthritis. Kinase inhibitors have shown promising oral disease-modifying antirheumatic drug potential with efficacy similar to anti-TNF biologics. Direct and indirect inhibition of the JAKs, with small molecule inhibitors like CP-690,550 and INCB018424 or neutralizing Abs, such as the anti-IL6 receptor Ab tocilizumab, have demonstrated rapid and sustained improvement in clinical measures of disease, consistent with their respective preclinical experiments. Therefore, it is of interest to identify optimized JAK inhibitors with unique profiles to maximize therapeutic opportunities. INCB028050 is a selective orally bioavailable JAK1/JAK2 inhibitor with nanomolar potency against JAK1 (5.9 nM) and JAK2 (5.7 nM). INCB028050 inhibits intracellular signaling of multiple proinflammatory cytokines including IL-6 and IL-23 at concentrations <50 nM. Significant efficacy, as assessed by improvements in clinical, histologic and radiographic signs of disease, was achieved in the rat adjuvant arthritis model with doses of INCB028050 providing partial and/or periodic inhibition of JAK1/JAK2 and no inhibition of JAK3. Diminution of inflammatory Th1 and Th17 associated cytokine mRNA levels was observed in the draining lymph nodes of treated rats. INCB028050 was also effective in multiple murine models of arthritis, with no evidence of suppression of humoral immunity or adverse hematologic effects. These data suggest that fractional inhibition of JAK1 and JAK2 is sufficient for significant activity in autoimmune disease models. Clinical evaluation of INCB028050 in RA is ongoing.
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