👤 Lisa F Newcomb

Anti-inflammatory effects of incretin signaling through the glucagon-like peptide-1 receptor (GLP-1R) and the glucose-dependent insulinotropic polypeptide receptor (GIPR) in mice have been reported. Therefore, we hypothesized that signaling through the endogenous GLP-1R and the GIPR individually decreases allergic airway inflammation and that the combination of GLP-1R and GIPR signaling together additively inhibits allergen-induced lung and airway inflammation. WT (C57BL/6J), GLP-1R knockout (KO), GIPR KO, and GLP-1R/GIPR double KO (DKO) mice were challenged intranasally with Alternaria alternata extract (Alt-Ext) or vehicle to evaluate the impact of signaling through these receptors on the innate allergen-induced inflammatory response that is primarily driven by group 2 innate lymphoid cells (ILC2). Alt-Ext-induced IL-33 release in the bronchoalveolar lavage fluid (BALF) was not different between the mouse strains, but thymic stromal lymphopoietin (TSLP) was significantly increased in GLP-1R/GIPR DKO mice challenged with Alt-Ext compared to the other strains. Furthermore, Alt-Ext-induced protein expression of IL-5, IL-13, CCL11, and CCL24 in the lung homogenates, the number of eosinophils, lymphocytes, and neutrophils in the BALF, and the number of lung GATA3+ ILC2 were significantly increased in GLP-1R/GIPR DKO mice compared to the other 3 strains. Furthermore, ICAM-1 expression on lung epithelial cells was increased in GLP-1R/GIPR DKO mice challenged with Alt-Ext compared to the other 3 strains. Deficiency of both GLP-1R and GIPR signaling together increased TSLP release, ILC2 activation, and early type 2 innate immune responses to aeroallergen exposure. Combined GLP-1R and GIPR signaling should be explored for the treatment of asthma. Show less

Men diagnosed with low-risk prostate cancer (PC) are increasingly electing active surveillance (AS) as their initial management strategy. While this may reduce the side effects of treatment for prostate cancer, many men on AS eventually convert to active treatment. PC is one of the most heritable cancers, and genetic factors that predispose to aggressive tumors may help distinguish men who are more likely to discontinue AS. To investigate this, we undertook a multi-institutional genome-wide association study (GWAS) of 5,222 PC patients and 1,139 other patients from replication cohorts, all of whom initially elected AS and were followed over time for the potential outcome of conversion from AS to active treatment. In the GWAS we detected 18 variants associated with conversion, 15 of which were not previously associated with PC risk. With a transcriptome-wide association study (TWAS), we found two genes associated with conversion ( Show less

Saccharomyces cerevisiae cells reproduce by budding to yield a mother cell and a smaller daughter cell. Although both mother and daughter begin G1 simultaneously, the mother cell progresses through G1 more rapidly. Daughter cell G1 delay has long been thought to be due to a requirement for attaining a certain critical cell size before passing the commitment point in the cell cycle known as START. We present an alternative model in which the daughter cell-specific Ace2 transcription factor delays G1 in daughter cells. Deletion of ACE2 produces daughter cells that proceed through G1 at the same rate as mother cells, whereas a mutant Ace2 protein that is not restricted to daughter cells delays G1 equally in both mothers and daughters. The differential in G1 length between mothers and daughters requires the Cln3 G1 cyclin, and CLN3-GFP reporter expression is reduced in daughters in an ACE2-dependent manner. Specific daughter delay elements in the CLN3 promoter are required for normal daughter G1 delay, and these elements bind to an unidentified 127-kDa protein. This DNA-binding activity is enhanced by deletion of ACE2. These results support a model in which daughter cell G1 delay is determined not by cell size but by an intrinsic property of the daughter cell generated by asymmetric cell division. Show less

Nutrient-limited Saccharomyces cerevisiae cells rapidly resume proliferative growth when transferred into glucose medium. This is preceded by a rapid increase in CLN3, BCK2, and CDC28 mRNAs encoding cell cycle regulatory proteins that promote progress through Start. We have tested the ability of mutations in known glucose signaling pathways to block glucose induction of CLN3, BCK2, and CDC28. We find that loss of the Snf3 and Rgt2 glucose sensors does not block glucose induction, nor does deletion of HXK2, encoding the hexokinase isoenzyme involved in glucose repression signaling. Rapamycin blockade of the Tor nutrient sensing pathway does not block the glucose response. Addition of 2-deoxy glucose to the medium will not substitute for glucose. These results indicate that glucose metabolism generates the signal required for induction of CLN3, BCK2, and CDC28. In support of this conclusion, we find that addition of iodoacetate, an inhibitor of the glyceraldehyde-3-phosphate dehydrogenase step in yeast glycolysis, strongly downregulates the levels CLN3, BCK2, and CDC28 mRNAs. Furthermore, mutations in PFK1 and PFK2, which encode phosphofructokinase isoforms, inhibit glucose induction of CLN3, BCK2, and CDC28. These results indicate a link between the rate of glycolysis and the expression of genes that are critical for passage through G(1). Show less

Transcription of the CLN3 G(1) cyclin in Saccharomyces cerevisiae is positively regulated by glucose in a process that involves a set of DNA elements with the sequence AAGAAAAA (A(2)GA(5)). To identify proteins that interact with these elements, we used a 1-hybrid approach, which yielded a nuclear zinc finger protein previously identified as Azf1. Gel shift and chromatin immunoprecipitation experiments show that Azf1 binds to the A(2)GA(5) CLN3 regulatory sequences in vitro and in vivo, thus identifying a transcriptional regulatory protein for CLN3 and a DNA sequence target for Azf1. We show that glucose-induced expression of a reporter gene driven by the A(2)GA(5) CLN3 regulatory sequences is dependent upon the presence of AZF1. Furthermore, deletion of AZF1 markedly reduces the transcriptional induction of CLN3 by glucose. In addition, Azf1 can induce reporter expression in a glucose-specific manner when artificially tethered to a promoter via the DNA-binding domain from Gal4. We conclude that AZF1 is a glucose-dependent transcription factor that interacts with the CLN3 A(2)GA(5) repeats to play a positive role in the regulation of CLN3 mRNA expression by glucose. Show less

When Saccharomyces cerevisiae cells are transferred from poor medium to fresh medium containing glucose, they rapidly increase the transcription of a large group of genes as they resume rapid growth and accelerate progress through the cell cycle. Among those genes induced by glucose is CLN3, encoding a G(1) cyclin that is thought to play a pivotal role in progression through Start. Deletion of CLN3 delays the increase in proliferation normally observed in response to glucose medium. ADA2 and ADA3/NGG1 are necessary for the rapid induction of CLN3 message levels in response to glucose. Loss of either ADA2 or ADA3/NGG1 also affects a large number of genes and inhibits the rapid global increase in transcription that occurs in response to glucose. Surprisingly, these effects are transitory, and expression of CLN3 and total poly(A)(+) RNA appear normal when ADA2 or ADA3/NGG1 deletion mutants are examined in log-phase growth. These results indicate a role for ADA2 and ADA3/NGG1 in allowing rapid transcriptional responses to environmental signals. Consistent with the role of the Ada proteins in positive regulation of CLN3, deletion of RPD3, encoding a histone deacetylase, prevented the down regulation of CLN3 mRNA in the absence of glucose. Show less