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Fang Yu

Bio: Fang Yu is an academic researcher from University of Nebraska Medical Center. The author has contributed to research in topics: Pancreatic cancer & Cancer. The author has an hindex of 32, co-authored 115 publications receiving 3566 citations.


Papers
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Journal ArticleDOI
TL;DR: To examine the degree to which shared risk factors explain the relationship of periodontitis to rheumatoid arthritis (RA) and to determine the associations of PD and Porphyromonas gingivalis with pathologic and clinical features of RA.
Abstract: Periodontitis (PD) has emerged as a risk factor in a number of health conditions including rheumatoid arthritis (RA) (1). Sharing both morphologic and histopathologic similarities with RA (2), PD is an inflammatory disease initiated by bacterial infection resulting in soft and hard tissue destruction and ultimately leading to tooth loss. In addition to shared inflammatory pathways, PD and RA share risk factors for susceptibility and progression, most notably cigarette smoking and, possibly, shared epitope-containing HLA-DRB1 alleles, the latter associated with localized aggressive periodontitis (3–10). Although a causal link between these conditions has not been established, several reports have demonstrated an increased PD prevalence in RA patients compared to controls (11–18). Growing evidence suggests that pathogens associated with PD could play a role in RA propagation. Chief among the organisms of interest is Porphyromonas gingivalis (P. gingivalis) (19). P. gingivalis is the only known pathogen expressing peptidylarginine deiminase (PPAD). Similar to its human counterpart, P. gingivalis-expressed PAD catalyzes the citrullination of arginine-containing peptides. This is noteworthy because citrullinated antigens are thought to drive adaptive immune responses that are nearly exclusive to RA. The potential role of P. gingivalis in RA pathogenesis has been borne out in epidemiologic investigations. Concentrations of circulating antibody to P. gingivalis have been demonstrated to be associated with the expression of anti-citrullinated peptide antibody (ACPA) (20–22). More recently, our group has shown that antibody to P. gingivalis is associated with the presence of RA-related autoantibody (a combination of rheumatoid factor [RF] and/or ACPA) among individuals at increased risk for disease but who have not yet developed RA symptoms (23), underscoring the potential role of this pathogen in RA development. As part of the present study, we conducted a large case-control investigation to examine the relationship of PD with established RA. We sought to examine the degree to which this relationship is impacted by shared genetic and/or environmental factors. We also sought to elucidate the degree to which the relationship of PD with RA may be related to infection and/or colonization with P. gingivalis. By using a rigorously selected control population, we attempted to mitigate issues of bias or unmeasured confounding that may have impacted other efforts often using healthy volunteers as comparators (16–18). Finally, using a multiplex approach, we examined the associations of PD and P. gingivalis with autoreactivity to several citrullinated autoantigens that have been implicated in RA disease pathogenesis.

333 citations

Journal ArticleDOI
TL;DR: A widely prevalent mechanism of resistance to gemcitabine in pancreatic cancer is established, whereby increased glycolytic flux leads to glucose addiction in cancer cells and a corresponding increase in pyrimidine biosynthesis to enhance the intrinsic levels of deoxycytidine triphosphate (dCTP).

331 citations

Journal ArticleDOI
TL;DR: The hypothesis that infection with P gingivalis may play a central role in the early loss of tolerance to self antigens that occurs in the pathogenesis of rheumatoid arthritis is supported.
Abstract: Objective. To examine the relationship of Porphyromonas gingivalis to the presence of autoantibodies in individuals at risk of rheumatoid arthritis (RA). Methods. Study participants included the following: 1) a cohort enriched in subjects with HLA–DR4 and 2) subjects at risk of RA by virtue of having a first-degree relative with RA. None of the study subjects satisfied the American College of Rheumatology 1987 classification criteria for RA. Autoantibodies measured included anti–citrullinated protein antibody (ACPA; by second-generation anti–cyclic citrullinated peptide

203 citations

Journal ArticleDOI
TL;DR: The studies demonstrate that the cachectic phenotype is in part due to metabolic alterations in tumor cells, which can be reverted by a ketogenic diet, causing reduced tumor growth and inhibition of muscle and body weight loss.
Abstract: Background: Aberrant energy metabolism is a hallmark of cancer. To fulfill the increased energy requirements, tumor cells secrete cytokines/factors inducing muscle and fat degradation in cancer patients, a condition known as cancer cachexia. It accounts for nearly 20% of all cancer-related deaths. However, the mechanistic basis of cancer cachexia and therapies targeting cancer cachexia thus far remain elusive. A ketogenic diet, a high-fat and low-carbohydrate diet that elevates circulating levels of ketone bodies (i.e., acetoacetate, β-hydroxybutyrate, and acetone), serves as an alternative energy source. It has also been proposed that a ketogenic diet leads to systemic metabolic changes. Keeping in view the significant role of metabolic alterations in cancer, we hypothesized that a ketogenic diet may diminish glycolytic flux in tumor cells to alleviate cachexia syndrome and, hence, may provide an efficient therapeutic strategy. Results: We observed reduced glycolytic flux in tumor cells upon treatment with ketone bodies. Ketone bodies also diminished glutamine uptake, overall ATP content, and survival in multiple pancreatic cancer cell lines, while inducing apoptosis. A decrease in levels of c-Myc, a metabolic master regulator, and its recruitment on glycolytic gene promoters, was in part responsible for the metabolic phenotype in tumor cells. Ketone body-induced intracellular metabolomic reprogramming in pancreatic cancer cells also leads to a significantly diminished cachexia in cell line models. Our mouse orthotopic xenograft models further confirmed the effect of a ketogenic diet in diminishing tumor growth and cachexia. Conclusions: Thus, our studies demonstrate that the cachectic phenotype is in part due to metabolic alterations in tumor cells, which can be reverted by a ketogenic diet, causing reduced tumor growth and inhibition of muscle and body weight loss.

191 citations

Journal ArticleDOI
TL;DR: It is demonstrated that MUC1, a large, type I transmembrane protein that is overexpressed in several carcinomas including pancreatic adenocarcinoma, modulates cancer cell metabolism to facilitate growth properties of cancer cells.
Abstract: Aberrant glucose metabolism is one of the hallmarks of cancer that facilitates cancer cell survival and proliferation. Here, we demonstrate that MUC1, a large, type I transmembrane protein that is overexpressed in several carcinomas including pancreatic adenocarcinoma, modulates cancer cell metabolism to facilitate growth properties of cancer cells. MUC1 occupies the promoter elements of multiple genes directly involved in glucose metabolism and regulates their expression. Furthermore, MUC1 expression enhances glycolytic activity in pancreatic cancer cells. We also demonstrate that MUC1 expression enhances in vivo glucose uptake and expression of genes involved in glucose uptake and metabolism in orthotopic implantation models of pancreatic cancer. The MUC1 cytoplasmic tail is known to activate multiple signaling pathways through its interactions with several transcription factors/coregulators at the promoter elements of various genes. Our results indicate that MUC1 acts as a modulator of the hypoxic response in pancreatic cancer cells by regulating the expression/stability and activity of hypoxia-inducible factor-1α (HIF-1α). MUC1 physically interacts with HIF-1α and p300 and stabilizes the former at the protein level. By using a ChIP assay, we demonstrate that MUC1 facilitates recruitment of HIF-1α and p300 on glycolytic gene promoters in a hypoxia-dependent manner. Also, by metabolomic studies, we demonstrate that MUC1 regulates multiple metabolite intermediates in the glucose and amino acid metabolic pathways. Thus, our studies indicate that MUC1 acts as a master regulator of the metabolic program and facilitates metabolic alterations in the hypoxic environments that help tumor cells survive and proliferate under such conditions.

190 citations


Cited by
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28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

18,940 citations

Journal ArticleDOI
TL;DR: This review summarizes the most recent advances in the field over the past 4 years, specifically highlighting new and interesting discoveries in tissue engineering and drug delivery applications.
Abstract: Utilization of polymers as biomaterials has greatly impacted the advancement of modern medicine. Specifically, polymeric biomaterials that are biodegradable provide the significant advantage of being able to be broken down and removed after they have served their function. Applications are wide ranging with degradable polymers being used clinically as surgical sutures and implants. In order to fit functional demand, materials with desired physical, chemical, biological, biomechanical and degradation properties must be selected. Fortunately, a wide range of natural and synthetic degradable polymers has been investigated for biomedical applications with novel materials constantly being developed to meet new challenges. This review summarizes the most recent advances in the field over the past 4 years, specifically highlighting new and interesting discoveries in tissue engineering and drug delivery applications.

1,712 citations

Journal ArticleDOI
TL;DR: The mechanisms of microbial immune subversion that tip the balance from homeostasis to disease in oral or extra-oral sites are discussed.
Abstract: Periodontitis is a dysbiotic inflammatory disease with an adverse impact on systemic health. Recent studies have provided insights into the emergence and persistence of dysbiotic oral microbial communities that can mediate inflammatory pathology at local as well as distant sites. This Review discusses the mechanisms of microbial immune subversion that tip the balance from homeostasis to disease in oral or extra-oral sites.

1,621 citations