Search

The pleiotropic actions of the Farnesoid X Receptor (FXR) are required for gut health, and reciprocally, reduced intestinal FXR signaling is seen in inflammatory bowel diseases (IBDs). Here, we show that activation of FXR selectively in the intestine is protective in inflammation-driven models of IBD. Prophylactic activation of FXR restored homeostatic levels of pro-inflammatory cytokines, most notably IL17. Importantly, these changes were attributed to FXR regulation of innate lymphoid cells (ILCs), with both the inflammation-driven increases in ILCs, and ILC3s in particular, and the induction of Il17a and Il17f in ILC3s blocked by FXR activation. Moreover, a population of ILC precursor-like cells increased with treatment, implicating FXR in the maturation/differentiation of ILC precursors. These findings identify FXR as an intrinsic regulator of intestinal ILCs and a potential therapeutic target in inflammatory intestinal diseases.

Liver fibrosis is characterized by the persistent deposition of extracellular matrix components by hepatic stellate cell (HSC)-derived myofibroblasts. It is the histological manifestation of progressive, but reversible wound-healing processes. An unabated fibrotic response results in chronic liver disease and cirrhosis, a pathological precursor of hepatocellular carcinoma. We report here that JQ1, a small molecule inhibitor of bromodomain-containing protein 4 (BRD4), a member of bromodomain and extraterminal (BET) proteins, abrogate cytokine-induced activation of HSCs. Cistromic analyses reveal that BRD4 is highly enriched at enhancers associated with genes involved in multiple profibrotic pathways, where BRD4 is colocalized with profibrotic transcription factors. Furthermore, we show that JQ1 is not only protective, but can reverse the fibrotic response in carbon tetrachloride-induced fibrosis in mouse models. Our results implicate that BRD4 can act as a global genomic regulator to direct the fibrotic response through its coordinated regulation of myofibroblast transcription. This suggests BRD4 as a potential therapeutic target for patients with fibrotic complications.

Increased levels of intestinal bile acids (BAs) are a risk factor for colorectal cancer (CRC). Here we show that the convergence of dietary factors (high-fat diet) and dysregulated WNT signaling (APC mutation) alters BA profiles to drive malignant transformations in Lgr5-expressing (Lgr5(+)) cancer stem cells and promote an adenoma-to-adenocarcinoma progression. Mechanistically, we show that BAs that antagonize intestinal Farnesoid X receptor (FXR) function, including tauro-β-muricholic acid (T-βMCA) and deoxycholic acid (DCA), induce proliferation and DNA damage in Lgr5(+) cells. Conversely, selective activation of intestinal FXR can restrict abnormal Lgr5(+) cell growth and curtail CRC progression. This unexpected role for FXR in coordinating intestinal self-renewal with BA levels implicates FXR as a potential therapeutic target for CRC.

Summary: PGC1α is a pleiotropic co-factor that affects angiogenesis, mitochondrial biogenesis, and oxidative muscle remodeling via its association with multiple transcription factors, including the master oxidative nuclear receptor ERRγ. To decipher their epistatic relationship, we explored ERRγ gain of function in muscle-specific PGC1α/β double-knockout (PKO) mice. ERRγ-driven transcriptional reprogramming largely rescues muscle damage and improves muscle function in PKO mice, inducing mitochondrial biogenesis, antioxidant defense, angiogenesis, and a glycolytic-to-oxidative fiber-type transformation independent of PGC1α/β. Furthermore, in combination with voluntary exercise, ERRγ gain of function largely restores mitochondrial energetic deficits in PKO muscle, resulting in a 5-fold increase in running performance. Thus, while PGC1s can interact with multiple transcription factors, these findings implicate ERRs as the major molecular target through which PGC1α/β regulates both innate and adaptive energy metabolism. : Fan et al. demonstrate that ERRγ improves mitochondrial energy metabolism in PGC1α/β-deficient muscle through its direct activation of target genes. Such ERRγ-induced effects are further boosted in combination with exercise training, suggesting ERRs are the major transcriptional modulator through which PGC1α/β regulates both innate and adaptive energy metabolism. Keywords: ERR, estrogen related receptor, PGC1, mitochondria, muscle, exercise, vasculature, fatty acid oxidation, glycolysis, muscle damage

Management of energy stores is critical during endurance exercise, with a shift in substrate utilization from glucose towards fat being a hallmark of trained muscle. Here we show that this key metabolic adaptation is both dependent on muscle PPARδ and stimulated by PPARδ ligand. Furthermore, we find that muscle PPARδ expression positively correlates with endurance performance in BXD mouse reference populations. In addition to stimulating fatty acid metabolism in sedentary mice, PPARδ activation potently suppresses glucose catabolism and does so without affecting either muscle fiber type or mitochondrial content. By preserving systemic glucose levels PPARδ acts to delay the onset of hypoglycemia and extends running time by ~100 minutes in treated mice. Collectively, these results identify a bifurcated PPARδ program that underlies glucose sparing and highlight the potential of PPARδ-targeted exercise mimetics in the treatment of metabolic disease, dystrophies and unavoidably, the enhancement of athletic performance.

The tumor microenvironment plays multiple roles in tumor cell proliferation, differentiation, vascularity, and metastasis through tumor cell-stromal cell interactions. The molecular responses of tumor cells to drug treatment can modify or be modified by the molecular signaling in stromal cells. Therefore, understanding the molecular features of both tumor cells and the tumor microenvironment is crucial for understanding cancer biology and the discovery of targeted therapy. Patient-derived xenograft (PDX) tumor models contain human tumor cells growing in a mouse stromal environment and are widely used models for cancer research and drug discovery. In this study we have applied in situ hybridization to visualize gene expression in human tumor and mouse stroma by developing species-specific probes based on the RNAscope technology. Eight genes were selected for this study based on their roles in a wide range of human cancers: EGFR, ERBB2, FGF19, FGFR1, FGFR4, MET, PECAM1 and TGFB1. We designed human and mouse species-specific probes by targeting the most divergent regions ( In both CRC and liver cancer PDX tumors, human-specific probes detected strong expression of ERBB2, FGFR4, and MET in human tumor cells but no signals in mouse stromal cells. Conversely, the mouse-specific probes only detected expression of Erbb2, Fgfr4, and Met genes in mouse stromal cells. Notably, strong expression of several mouse genes, including Tgfb1, Fgfr1, Egfr, and Pecam1, were detected in the stroma surrounding the human tumor by mouse-specific probes while no human probe signals were detected in the same region. Human TGFB1, FGFR1, EGFR, and PECAM1 probes detected varied levels of gene expression in the human tumor cells from the same sample without cross-detection of the mouse ortholog sequences in the stromal region. We also observed extensive gene expression heterogeneity, both within the same tumor and between tumors. Heterogeneity of FGFR4 and FGF19 expression in the liver cancer model was particularly notable. Our results indicate that RNAscope, a single molecule RNA detection method can robustly detect the expression patterns of FGFR4-FGF19 in PDX tumors and can be utilized for selecting PDX models for mouse trials with therapeutic agents targeting FGFR4 signaling pathway. Overall the findings in this study demonstrate the successful use of RNAscope based in-situ hybridization to examine human tumor specific gene expression in mouse stromal environment in PDX animal models by visualizing gene expression in both the human tumor and mouse stroma with species-specific probes. As human tumor engrafts acquire mouse stromal cells during growth in the murine host, the method presented here will further enable the molecular dissection in PDX tumor models of tumor-host interactions involved in tumor growth, progression, and metastasis as well as responses to cancer drugs and development of drug resistance. Citation Format: Emily Park, Na Li, Katherine Ye, Mingxiao He, Mingxiao He, Zhifu Zhang, Hongzhe Sun, Xin Wang, Courtney Anderson, Yuling Luo, Zhenyu Gu, Xiao-Jun Ma. Dissecting molecular pathways in human tumor vs. mouse stromal environment in patient-derived cancer models. [abstract]. In: Proceedings of the AACR Special Conference: Patient-Derived Cancer Models: Present and Future Applications from Basic Science to the Clinic; Feb 11-14, 2016; New Orleans, LA. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(16_Suppl):Abstract nr B03.

Although feast and famine cycles illustrate that remodelling of adipose tissue in response to fluctuations in nutrient availability is essential for maintaining metabolic homeostasis, the underlying mechanisms remain poorly understood(1,2). Here we identify fibroblast growth factor 1 (FGF1) as a critical transducer in this process in mice, and link its regulation to the nuclear receptor PPAR gamma (peroxisome proliferator activated receptor gamma), which is the adipocyte master regulator and the target of the thiazolidinedione class of insulin sensitizing drugs(3-5). FGF1 is the prototype of the 22-member FGF family of proteins and has been implicated in a range of physiological processes, including development, wound healing and cardiovascular changes(6). Surprisingly, FGF1 knockout mice display no significant phenotype under standard laboratory conditions(7-9). We show that FGF1 is highly induced in adipose tissue in response to a high-fat diet and that mice lacking FGF1 develop an aggressive diabetic phenotype coupled to aberrant adipose expansion when challenged with a high-fat diet. Further analysis of adipose depots in FGF1-deficient mice revealed multiple histopathologies in the vasculature network, an accentuated inflammatory response, aberrant adipocyte size distribution and ectopic expression of pancreatic lipases. On withdrawal of the high-fat diet, this inflamed adipose tissue fails to properly resolve, resulting in extensive fat necrosis. In terms of mechanisms, we show that adipose induction of FGF1 in the fed state is regulated by PPAR gamma acting through an evolutionarily conserved promoter proximal PPAR response element within the FGF1 gene. The discovery of a phenotype for the FGF1 knockout mouse establishes the PPAR gamma-FGF1 axis as critical for maintaining metabolic homeostasis and insulin sensitization.

Wu Wei was the representative personage of Zhejiang painters. His lightsome ink and wild painting style attracted many people. He then became an unusual talent in painting history of Ming Dynasty. People who read Baqiao Bridge Snow Figure would feel rustle in the air at first, but then would find it expressed more that that. This paper tried to interpret this painting further more. Wu Wei (1459--1508), his style name, also known as courtesy name, was Ciwen. He also may be known by the pseudonym (Xiaoxian). He was the representative personage of Zhejiang painters in Ming dynasty from Jiangxia, Hubei. He was poor when he was a child and become homeless in Nanjing. He was devote himself to painting and became famous gradually after adopting by a family of public officials. He was summoned by three generations of the emperors for three times: he was awarded as Jinyizhenfu and worked in Renzhi palace in the reign of Emperor Mingwan; he was awarded Jin Yiwei Baihu and the imprint of very best painting in the reign of Emperor Mingxiao; he was recalled when Emperor Wuzong ascended. Imaging the constraint of backing to the palace, Wu Wei hung one on and died at the journey. Wu Wei behaved unbridledly all his life, just like his painting, bold and unrestrained. Now we could still see his landscape paintings, such as Baqiao Bridge Snow Figure, Footprints in the Snow, Fishing in the Snow. Now let's focus on Baqiao Bridge Snow Figure, it was a silk scroll ink painting with the length of 183.6 cm and width of 110.2 cm. It portrayed the scenery of Baqiao Bridge. In the picture, there was an ancient temple far away, a great river full of ice and snow in the middle, and deadwood with a donkey walking by in the close shot. The picture was quite overwhelming by using bold brush, crude line and articulate ink. It signed with Xiaoxian and printed with Wu Wei. Baqiao Bridge is a very famous ancient bridge, also called Enchantment bridge, located in east of Xian, Shaanxi. It was a vital communication line in old time, tang people used to say goodbye here. So there was a literary quotation of bid farewell in Baqiao Bridge. In the Complete Collection of Tang Poetry, there were hundreds of poetry related to this bridge. According to the record of the poetry of Yunfu Qunyu: poet Meng Haoran once came to Baqiao with a donkey in the snow, he said: "I am on the back of the donkey in the snow." Meng Haoran's experience became a much-told story, and painters always used this theme. Wu Wei's Baqiao Bridge Snow Figure was an example, which portrayed a scene of an old man riding across the bridge in the snow. The wild trees died in the cliff, the river was freeze, and an old man was riding a donkey across the bridge in the snow miserably. The riding figure was very simple but vivid and meaningful. The several strokes formed the vision focus of the painting and emphasized the poetic connotation. The painter abandoned vanity and noisy while putting coldness, desolation in it by describing white snow, rusty trees, the temple in the end of the mountain. Those barren scenes plus the shadow of the riding man made people feel melancholy. The two riding men looked particularly tiny and lonely against the large piece of snow mountain background. But what the painting wanted to express was more than loneliness. Wen Zhengming in Ming Dynasty said: "The recluse like to paint landscape for self entertainment and the snow is frequently emerged. Maybe they want to express their nobleness and high morality. " Painting snow reflected Chinese painters' romanticism. Snow means white, white means empty, white snow

Heat induced target retrieval (HITR) is a widely adopted approach for Immunohistochemistry (IHC) and in situ hybridization (ISH) applications on formalin fixed and paraffin embedded (FFPE) tissues to facilitate target access and increase detection sensitivity. A variety of factors, such as fixative type, fixation time, tissue type, epitope abundance, antibody affinity, and probe length greatly affect the efficiency of HITR. Given such variability, over the decades, multiple HITR buffer formulations and protocols were invented to fit the needs in different experimental scenarios. We have developed a novel HITR solution that allows highly efficient target retrieval for RNA ISH application based on the RNAscope technology. When tested on 15 different tumor types, the new HITR solution resulted in significantly better sensitivity and/or tissue morphology comparing to using traditional HITR buffers, including Citrate, EDTA, and Tris based buffers with various pH. Furthermore, this new HITR solution is highly tolerant to sample variability. When used on multiple human tumor tissue microarrays (TMAs), including breast, colon, lung, and gastric cancers, the new HITR solution improved overall signal-to-noise ratio and reduced core disqualification rate, compared to traditional citrate based HITR buffer for ISH. Moreover, when tested on multiple mouse tissues fixed with different types of fixatives for varying periods of time (6 - 72 hours), a single experimental condition with the new HITR solution showed comparable results in both detection sensitivity and morphological integrity in all the samples. It also allowed detection of a target (Tbp) with extremely low abundance ( Given that all the RNAscope probes are synthetic oligonucleotide probes with length shorter than 60 bases, the new HITR solution, in combination with the RNAscope technology, will allow universal detection of any RNA targets with single molecule detection sensitivity in FFPE tissues with minimal requirement for analytical condition optimization. Citation Format: Li-chong Wang, Liuliu Pan, Kuang-Jung Chang, Daniel Kim, Xingyong Wu, Hongwei Wang, Casey Kernag, Bingqing Zhang, Mingxiao He, Nan Su, Xiao-Jun Ma, Yuling Luo. Developing a universal target retrieval solution and protocol for RNA in situ hybridization based on RNAscope technology. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4904. doi:10.1158/1538-7445.AM2015-4904