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Both ErbB1 and ErbB2 are overexpressed or amplified in breast tumours. To examine the effects of activating ErbB receptors in a context that mimics polarized epithelial cells in vivo, we activated ErbB1 and ErbB2 homodimers in preformed, growth-arrested mammary acini cultured in threedimensional basement membrane gels. Activation of ErbB2, but not that of ErbB1, led to a reinitiation of cell proliferation and altered the properties of mammary acinar structures. These altered structures share several properties with early-stage tumours, including a loss of proliferative suppression, an absence of lumen, retention of the basement membrane and a lack of invasive properties. ErbB2 activation also disrupted tight junctions and the cell polarity of polarized epithelia, whereas ErbB1 activation did not have any effect. Our results indicate that ErbB receptors differ in their ability to induce early stages of mammary carcinogenesis in vitro and this three-dimensional model system can reveal biological activities of oncogenes that cannot be examined in vitro in standard transformation assays.The mammary epithelium of an adult breast is organized into ducts and lobules. The ducts end in a highly branched structure referred to as the terminal ductal lobular unit (TDLU). A TDLU is comprised of multiple individual units referred to as mammary acini. Each acinus has a central lumen, a single layer of polarized luminal epithelial cells surrounded by myoepithelial cells, and a basement membrane.We have previously shown that human mammary epithelial cells (MECs) form acini-like structures containing a single layer of polarized, growth-arrested cells when grown within a matrix rich in laminin and collagen IV (Matrigel, derived from the Englebreth-Holm Swarm (EHS) tumour) 1,2 . The epithelial cells within acini in vivo and in culture have an apico-basal distribution of polarity markers such as ZO-1, E-cadherin and α 6 β 4 integrins. They also deposit collagen IV and secrete sialomucin in their basal and apical surfaces, respectively 1,2 , indicating that the acinar structures formed in culture closely mimic the acini in an adult breast.Early stages of breast cancer (hyperplasia and ductal carcinoma in situ (DCIS)) are characterized by an increased proliferation of epithelial cells, a loss of acinar organization and § Correspondence and requests for materials should be addressed to J.S.B. joan_brugge@hms.harvard.edu. † Present addresses: Cold Spring Harbor Laboratories, Cold Spring Harbor, New York 11724, USA (S.K.M.); Department of Basic Medical Sciences, Purdue University, West Lafayette, Indiana 47907, USA (S.L.)Supplementary information is available on Nature Cell Biology's website (http://cellbio.nature.com) or as paper copy from the London editorial office of Nature Cell Biology. NIH Public Access Author ManuscriptNat Cell Biol. Author manuscript; available in PMC 2010 October 11. filling of the luminal space 3 . However, a lack of acinar organization and the acquisition of invasive behaviour are later events involved...

Cryptochromes are blue, ultraviolet-A photoreceptors. They were first characterized for Arabidopsis and are also found in ferns and algae; they appear to be ubiquitous in the plant kingdom. They are flavoproteins similar in sequence to photolyases, their presumptive evolutionary ancestors. Cryptochromes mediate a variety of light responses, including entrainment of circadian rhythms in Arabidopsis, Drosophila, and mammals. Sequence comparison indicates that the plant and animal cryptochrome families have distinct evolutionary histories, with the plant cryptochromes being of ancient evolutionary origin and the animal cryptochromes having evolved relatively recently. This process of repeated evolution may have coincided with the origin in animals of a modified circadian clock based on the PERIOD, TIMELESS, CLOCK, and CYCLE proteins.

FGF21 plays a central role in energy, lipid, and glucose homeostasis. To characterize the pharmacologic effects of FGF21, we administered a long-acting FGF21 analog, PF-05231023, to obese cynomolgus monkeys. PF-05231023 caused a marked decrease in food intake that led to reduced body weight. To assess the effects of PF-05231023 in humans, we conducted a placebo-controlled, multiple ascending-dose study in overweight/obese subjects with type 2 diabetes. PF-05231023 treatment resulted in a significant decrease in body weight, improved plasma lipoprotein profile, and increased adiponectin levels. Importantly, there were no significant effects of PF-05231023 on glycemic control. PF-05231023 treatment led to dose-dependent changes in multiple markers of bone formation and resorption and elevated insulin-like growth factor 1. The favorable effects of PF-05231023 on body weight support further evaluation of this molecule for the treatment of obesity. Longer studies are needed to assess potential direct effects of FGF21 on bone in humans.

Adiponutrin and a related protein, adipocyte triglyceride lipase (ATGL; also known as Desnutrin), were recently described as adipocyte-specific proteins with lipid hydrolase activity. Using bioinformatics, we identified three additional Adiponutrin family members (GS2, GS2-Like, and PNPLA1). Here, we report on the expression, regulation, and activity of GS2 and GS2-Like compared with Adiponutrin and Desnutrin/ATGL. GS2-Like is expressed and regulated in a manner similar to Adiponutrin; however, the absolute levels of mRNA are significantly lower than those of Adiponutrin or Desnutrin/ATGL. GS2 transcripts were identified only in humans and are highly expressed in adipose as well as other tissues. All four proteins show lipase activity in vitro, which is dependent on the presence of the active site serine for Adiponutrin, Desnutrin/ATGL, and GS2. Overexpression of Desnutrin/ATGL, GS2, and GS2-Like, but not Adiponutrin, decreases intracellular triglyceride levels. This is consistent with a function for Desnutrin/ATGL, GS2, and GS2-Like in lipolysis, but not for Adiponutrin. Consistent with previously reported data, Desnutrin/ATGL is upregulated by fasting in adipose tissue, whereas Adiponutrin is downregulated. Additionally, Adiponutrin and GS2-Like, but not Desnutrin/ATGL, are strongly induced in the liver of ob/ob mice.Our data support distinct functions for Adiponutrin and Desnutrin/ATGL and raise the possibility that GS2 may contribute significantly to lipolysis in human adipose tissue.

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Abstract-Chronic heart failure (CHF) is often associated with excitation of the sympathetic nervous system. This event is thought to be a negative predictor of survival in CHF. Sympathoexcitation and central angiotensin II (Ang II) have been causally linked. Recent studies have shown that NAD(P)H oxidase-derived reactive oxidant species (ROS) are important mediators of Ang II signaling. In the present study, we tested the hypothesis that central Ang II activates sympathetic outflow by stimulation of NAD(P)H oxidase and ROS in the CHF state. CHF was induced in male New Zealand White rabbits by chronic ventricular tachycardia. Using radio telemetry of arterial pressure and intracerebroventricular infusions, experiments were performed in the conscious state. Renal sympathetic nerve activity (RSNA) was recorded as a direct measure of sympathetic outflow. Intracerebroventricular Ang II significantly increased RSNA in sham (131.5Ϯ13.3% of control) and CHF (193.6Ϯ11.9% of control) rabbits. The increase in CHF rabbits was significantly greater than in sham rabbits (PϽ0.01). These responses were abolished by intracerebroventricular losartan, tempol, or apocynin. Resting RSNA was significantly reduced by intracerebroventricular losartan, tempol, or apocynin in CHF rabbits but not in sham rabbits. Intracerebroventricular administration of the superoxide dismutase inhibitor diethyldithio-carbamic acid increased RSNA significantly more in sham compared with CHF rabbits. NADPHdependent superoxide anion production in the rostral ventrolateral medulla (RVLM) was increased by 2.9-fold in CHF rabbits compared with sham rabbits. Finally, increases in the RVLM mRNA and protein expression of Ang II type 1 (AT 1 ) receptor and subunits of NAD(P)H oxidase (p40 phox , p47 phox , and gp91 phox ) were demonstrated in CHF rabbits. These data demonstrate intense radical stress in autonomic areas of the brain in experimental CHF and provide evidence for a tight relationship between Ang II and ROS as contributors to sympathoexcitation in CHF. Key Words: free radicals Ⅲ angiotensin receptors Ⅲ RVLM Ⅲ ventricular pacing I t is now well accepted that neural and humoral excitation are two of the primary and most reproducible sequelae of the chronic heart failure (CHF) syndrome. 1 Excessive sympathetic activation not only exacerbates the heart failure state but also is prognostic of death and complications. 2 A variety of humoral substances have been shown to be elevated in the CHF state, 1,3 of which angiotensin II (Ang II) has been considered a prime candidate for a substance that modulates sympathetic outflow because it has been known for some time that Ang II can alter sympathetic function at several sites from the central nervous system to the periphery. 4 Indeed, many of the current therapeutic targets in the treatment of CHF relate to reducing Ang II generation or blocking the effects of Ang II at its receptor sites. Despite its importance in central regulation of sympathetic outflow and cardiovascular homeostasis in the CHF state, the pre...

This paper establishes a strong relation between technology competition and corporate bankruptcy. Using detailed firm-level patent data we show that: 1) the capability of firms to innovate predicts future bankruptcies better than the typical measures such as Z-score and credit rating, 2) technology-related bankruptcies are less sensitive to the business cycle and industry success, and 3) firms that go bankrupt as a result of technology competition experience larger declines in earnings and stock prices.