Differential responses of normal human coronary artery endothelial cells against multiple cytokines comparatively assessed by gene expression profiles

AbstractEndothelial cells play an important role in terms of biological functions by responding to a variety of stimuli in the blood. However, little is known about the molecular mechanism involved in rendering the variety in the cellular response. To investigate the variety of the cellular responses against exogenous stimuli at the gene expression level, we attempted to describe the cellular responses with comprehensive gene expression profiles, dissect them into multiple response patterns, and characterize the response patterns according to the information accumulated so far on the genes included in the patterns. We comparatively analyzed in parallel the gene expression profiles obtained with DNA microarrays from normal human coronary artery endothelial cells (HCAECs) stimulated with multiple cytokines, interleukin-1β, tumor necrosis factor-α, interferon-β, interferon-γ, and oncostatin M, which are profoundly involved in various functional responses of endothelial cells. These analyses revealed that the cellular responses of HCAECs against these cytokines included at least 15 response patterns specific to a single cytokine or common to multiple cytokines. Moreover, we statistically extracted genes contained within the individual response patterns and characterized the response patterns with the genes referring to the previously accumulated findings including the biological process defined by the Gene Ontology Consortium (GO). Out of the 15 response patterns in which at least one gene was successfully extracted through the statistical approach, 11 response patterns were differentially characterized by representing the number of genes contained in individual criteria of the biological process in the GO only. The approach to dissect cellular responses into response patterns and to characterize the pattern at the gene expression level may contribute to the gaining of insight for untangling the diversity of cellular functions

Identification of mutations through dominant screening for obesity using C57BL/6 substrains

The discovery of leptin substantiated the usefulness of a forward genetic approach in elucidating the molecular network regulating energy metabolism. However, no successful dominant screening for obesity has been reported, which may be due to the influence of quantitative trait loci between the screening and counter strains and the low fertility of obese mice. Here, we performed a dominant screening for obesity using C57BL/6 substrains, C57BL/6J and C57BL/6N, with the routine use of in vitro fertilization. The screening of more than 5000 mutagenized mice established two obese pedigrees in which single nucleotide substitutions in Mc4r and Sim1 genes were identified through whole-exome sequencing. The mutation in the Mc4r gene produces a premature stop codon, and the mutant SIM1 protein lacks transcriptional activity, showing that the haploinsufficiency of SIM1 and MC4R results in obesity. We further examined the hypothalamic neuropeptide expressions in the mutant pedigrees and mice with diet-induced obesity, which showed that each obesity mouse model has distinct neuropeptide expression profiles. This forward genetic screening scheme is useful and applicable to any research field in which mouse models work

ネコ ノ スイブン セッシュリョウ ト ニョウリョウ ニョウ ヒジュウチ ニ カンスル ケンキュウ

Domestic cats (Felissilvestriscatus ) are known to have lesser and hypertonic urine excretion(urine volume: 22–30 mL/kg per day; specific gravity: 1.015–1.050) than those of domestic dogs( Canislupus familiaris); urine volume: 24–40 mL/kg perday; specific gravity: 1.015–1.040). These have been implicated as factors for feline incidence of struviteurolithiasis and felinelower urinary tract disease, which are diseases that affect the bladder or urethra. We conducted comparative studies on therelationship between fluid intake and urine volume/urine specific gravity under 2 conditions—diet (condition A) comprising"dry food"( 5.6% moisture) and ad libitum drinking water and diet( condition B) comprising" wet food"( 74.8% moisture) andad libitum drinking water—in acclimated cats( n=7) kept separately in cat cages in an animal rearing room at 25°C. The perdiem water intake (apparent water intake) in condition A was on an average 66.9 ± 22.1(mL), while the totalfluid intake (absolute water intake), which is the sum of the amounts of water in the food and the water intake, was on anaverage68.2 ± 23.3(mL).Further, the average water intake under condition B was only 22.7 ± 20.13( mL), but the absolutewater intake was on average 95.6 ± 37.6( mL), meaning that wet food resulted in a higher absolute water intake amountthan dry food. Regarding the urine volume and the urine specific gravity, urine volume and urine specific gravity with the dry food diet(condition A) were 28.8 ± 11.8 (mL) and 1.049 ± 0.01, respectively, but the mean urine volume and urine specific gravityunder condition B were 49.5 ± 31.4(mL) and 1.030 ± 0.01, respectively, showing that compared to the dry food group, thewet food group had a significantly higher urine volume and lower urine specific gravity. The present study proves that in an average rearing environment, the urine volume does not increase and urine specificgravity is hypertonic when the cats are provided dry food diet, despite increase in the apparent water intake. Further, theurine volume increases and urine specific gravity decreases when the cats are provided wet food diet( canned or pouched),although the apparent water intake is low. The present study shows that differences in the diet are factors for the increasedincidence of struviteurolithiasis and FLUTD in cats

Hepatic rRNA Transcription Regulates High-Fat-Diet-Induced Obesity

Ribosome biosynthesis is a major intracellular energy-consuming process. We previously identified a nucleolar factor, nucleomethylin (NML), which regulates intracellular energy consumption by limiting rRNA transcription. Here, we show that, in livers of obese mice, the recruitment of NML to rRNA gene loci is increased to repress rRNA transcription. To clarify the relationship between obesity and rRNA transcription, we generated NML-null (NML-KO) mice. NML-KO mice show elevated rRNA level, reduced ATP concentration, and reduced lipid accumulation in the liver. Furthermore, in high-fat-diet (HFD)-fed NML-KO mice, hepatic rRNA levels are not decreased. Both weight gain and fat accumulation in HFD-fed NML-KO mice are significantly lower than those in HFD-fed wild-type mice. These findings indicate that rRNA transcriptional activation promotes hepatic energy consumption, which alters hepatic lipid metabolism. Namely, hepatic rRNA transcriptional repression by HFD feeding is essential for energy storage

Genomic analysis of pancreatic juice DNA assesses malignant risk of intraductal papillary mucinous neoplasm of pancreas

Abstract Intraductal papillary mucinous neoplasm (IPMN) of pancreas has a high risk to develop into invasive cancer or co‐occur with malignant lesion. Therefore, it is important to assess its malignant risk by less‐invasive approach. Pancreatic juice cell‐free DNA (PJD) would be an ideal material in this purpose, but genetic biomarkers for predicting malignant risk from PJD are not yet established. We here performed deep exome sequencing analysis of PJD from 39 IPMN patients with or without malignant lesion. Somatic alterations and copy number alterations (CNAs) detected in PJD were compared with the histologic grade of IPMN to evaluate their potential as a malignancy marker. Somatic mutations of KRAS, GNAS, TP53, and RNF43 were commonly detected in PJD of IPMNs, but no association with the histologic grades of IPMN was found. Instead, mutation burden was positively correlated with the histologic grade (r = 0.427, P = 0.015). We also observed frequent copy number deletions in 17p13 (TP53) and amplifications in 7q21 and 8q24 (MYC) in PJDs. The amplifications in 7q21 and 8q24 were positively correlated with the histologic grade and most prevalent in the cases of invasive carcinoma (P = 0.002 and 7/11; P = 0.011 and 6/11, respectively). We concluded that mutation burden and CNAs detected in PJD may have potential to assess the malignant progression risk of IPMNs