A mutation within the obese gene was recently identified as the genetic basis for obesity in the ob/ob mouse. The obese gene product, leptin, is a 16-kDa protein expressed predominantly in adipose tissue. Consistent with leptin's postulated role as an extracellular signaling protein, human embryonic kidney 293 cells transfected with the obese gene secreted leptin with minimal intracellular accumulation. Upon differentiation of 3T3-L1 preadipocytes into adipocytes, the leptin mRNA was expressed concomitant with mRNAs encoding adipocyte marker proteins. A factor(s) present in calf serum markedly activated expression of leptin by fully differentiated 3T3-L1 adipocytes. A 16-hr fast decreased (by -85%) the leptin mRNA level of adipose tissue of lean (ob/+ or +/+) mice but had no effect on the -4-fold higher level in obese (ob/ob) litterniates. Since the mutation at the ob locus fails to produce the functional protein, yet its cognate mRNA is overproduced, it appears that leptin is necessary for its own downregulation. Leptin mRNA was also suppressed in adipose tissue of rats during a 16-hr fast and was rapidly induced during a 4-hr refeeding period. Insulin deficiency provoked by streptozotocin also markedly down-regulated leptin mRNA and this suppression was rapidly reversed by insulin. These results suggest that insulin may regulate the expression of leptin.The ob/ob mouse has been widely investigated as a model of genetic obesity (1, 2) since the discovery of the ob mutation in 1950 (3). The phenotype of mice that are homozygous for the ob mutation is characterized by hyperinsulinemia, hyperglucocorticoidemia, hyperglycemia, insulin resistance, altered central nervous system activity, hyperphagia, reduced metabolic rate of brown adipose tissue, and a massive increase in white adipose tissue (reviewed in refs. 1, 2, and 4). As many of these phenotypic characteristics, including adipocyte hypertrophy and hyperplasia, develop in ob/ob mice before the onset of hyperphagia, it is evident that initiation of obesity in this model does not result solely from elevated energy intake. Indeed, obesity occurs even in ob/ob mice pair-fed to the level of energy intake of their lean littermates. Parabiosis experiments with ob/ob mice indicate that a factor circulating in the bloodstream of lean (ob/ob littermates) or db/db mice reverses the effects of the ob mutation (5, 6). More recently, Friedman's group (7) mapped the ob locus, cloned the ob gene, and showed that the gene is primarily, if not exclusively, expressed in adipose tissue of normal rodents. The deduced amino acid sequence of the gene product, referred to hereafter as leptin (8), specifies a 16-kDa protein that possesses a leader sequence and presumably is secreted. The apparent secretory nature of leptin is consistent with a large body of evidence linking the dysfunction (or dysregulation) in ob/ob mice, including feeding behavior, to the hypothalamus (2, 4). As the effects of mutations at the ob locus are pleiotropic, it is possible that leptin also intera...

Carbohydrate antigens with subterminal fucosylation have been implicated in the development and progression of several cancers, including hepatocellular carcinoma (HCC). Fluorescent sensors targeting fucosylated carbohydrate antigens could potentially be used for diagnostic and other applications. We have designed and synthesized a series of 26 diboronic acid compounds as potential fluorescent sensors for such carbohydrates. Among these compounds, 7q was able to fluorescently label cells expressing high levels of sLex (HEPG2) within a concentration range of 0.5 to 10 microM. This compound (7q) did not label cells expressing Lewis Y (HEP3B), nor cells without fucosylated antigens (COS7). This represents the first example of a fluorescent compound labeling cells based on cell surface carbohydrate structures.

We investigated whether oxygen radicals generated during ischemia-reperfusion trigger postischemic inflammation in the heart. Closed-chest dogs underwent 90-min coronary artery occlusion, followed by 1- or 3-h reperfusion: 10 dogs received the cell-permeant oxygen radical scavenger N-(2-mercaptopropionyl)-glycine (MPG; 8 mg x kg(-1) x h(-1) intracoronary) beginning 5 min before reperfusion, and 9 dogs received vehicle. Blood flow (microspheres), intercellular adhesion molecule (ICAM)-1 protein expression (immunohistochemistry), ICAM-1 gene activation (Northern blotting), nuclear DNA binding activity of nuclear factor (NF)-kappaB and AP-1 (electrophoretic mobility shift assays), and neutrophil (PMN) accumulation (myeloperoxidase activity) were assessed in myocardial tissue samples. ICAM-1 protein expression was high in vascular endothelium after ischemia-reperfusion but was markedly reduced by MPG. MPG treatment also markedly decreased expression of ICAM-1 mRNA and tissue PMN accumulation. Nuclear DNA binding activities of NF-kappaB and AP-1, increased by ischemia-reperfusion, were both markedly decreased by MPG at 1 h of reperfusion. However, by 3 h, AP-1 activity was only modestly reduced by MPG and NF-kappaB activity was not significantly different from ischemic-reperfused controls. These results suggest that oxygen radicals generated in vivo during reperfusion trigger early activation of NF-kappaB and AP-1, resulting in upregulation of the ICAM-1 gene in vascular endothelium and subsequent tissue accumulation of activated PMNs.

Knowledge of cooperative breeding in birds from longitudinal studies is available only for a small proportion of species. This paper reports data from a 12‐year study on the Tibetan Ground Tit Pseudopodoces humilis. On average, 27.2% (range: 13.0–36.1%) of monogamous pairs in each year contained one (85.4%) or more (14.6%) male helpers, 83.7% of which were yearlings staying on natal territories. Most helpers (89.6%) helped once and then bred independently. Adults had male‐biased sex ratios, low annual survival rates (averaging 0.50) and shorter longevities (averaging 1.8 years) compared with low‐altitude avian cooperative breeders, suggesting that mate shortage promotes helping behaviour in this species. Incest occurred rarely (2.1% of pairs), probably because kin recognition occurs through year‐around living in family groups. There was a low level (3.1% of broods) of extra‐pair parentage, which could facilitate the maintenance of cooperative breeding.

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BackgroundThe pulmonary phenotype in cystic fibrosis (CF) is variable; thus, environmental and genetic factors likely contribute to clinical heterogeneity. We hypothesized that genetically determined ABO histo-blood group antigen (ABH) differences in glycosylation may lead to differences in microbial binding by airway mucus, and thus predispose to early lung infection and more severe lung disease in a subset of patients with CF.Methods and Principal FindingsClinical information and DNA was collected on >800 patients with the ΔF508/ΔF508 genotype. Patients in the most severe and mildest quartiles for lung phenotype were enrolled. Blood samples underwent lymphocyte transformation and DNA extraction using standard methods. PCR and sequencing were performed using standard techniques to identify the 9 SNPs required to determine ABO blood type, and to identify the four SNPs that account for 90–95% of Lewis status in Caucasians. Allele identification of the one nonsynonymous SNP in FUT2 that accounts for >95% of the incidence of nonsecretor phenotype in Caucasians was completed using an ABI Taqman assay. The overall prevalence of ABO types, and of FUT2 (secretor) and FUT 3 (Lewis) alleles was consistent with that found in the Caucasian population. There was no difference in distribution of ABH type in the severe versus mild patients, or the age of onset of Pseudomonas aeruginosa infection in the severe or mild groups. Multivariate analyses of other clinical phenotypes, including gender, asthma, and meconium ileus demonstrated no differences between groups based on ABH type.Conclusions and SignificancePolymorphisms in the genes encoding ABO blood type, secretor or Lewis genotypes were not shown to associate with severity of CF lung disease, or age of onset of P. aeruginosa infection, nor was there any association with other clinical phenotypes in a group of 808 patients homozygous for the ΔF508 mutation.

Cervical cancer is one of the major malignancies, the pathophysiology and progression of which remain to be scarcely understood. Long non‐coding RNAs (lncRNAs) have been previously implicated in the progression of cervical cancer. Here, the purpose of this study was to identify whether lncRNA heart‐ and neural crest derivative‐expressed 2‐antisense RNA 1 (HAND2‐AS1) affect the development of cervical cancer through regulation of chromosome 16 open reading frame 74 (C16orf74) by mediating a transcription factor E2F4. RT‐qPCR was performed to determine the expression of HAND2‐AS1 in cervical cancer cells. Then, cervical cancer cells were treated with HAND2‐AS1 or si‐E2F4 RNA, or C16orf74, after which the proliferation, colony formation, migration and invasion were detected. Moreover, the binding between HAND2‐AS1 and E2F4 or between E2F4 and C16orf74 was explored. Finally, the tumorigenesis of cervical cancer cells was measured in nude mice with altered HAND2‐AS1/E2F4/C16orf74 expression. HAND2‐AS1 exhibited poor expression in cervical cancer, and HAND2‐AS1 overexpression suppressed the proliferation, colony formation, migration and invasion of cervical cancer cells. In addition, HAND2‐AS1 was found to recruit transcription factor E2F4 to C16orf74 promoter region and down‐regulate C16orf74 expression. Lastly, HAND2‐AS1/E2F4/C16orf74 modulated the tumorigenesis of cervical cancer in nude mice. In conclusion, this study provided evidence on the inhibitory effect of HAND2‐AS1 on the development of cervical cancer through the suppression of C16orf74 expression by recruiting transcription factor E2F4. This study highlights the potential of lncRNA HAND2‐AS1 as a target in the treatment of cervical cancer.

BackgroundChina is a high tuberculosis (TB) burden country. More than half of acute TB cases first seek medical care in village doctors’ clinics or community health centers. Despite being responsible for patient referral and management, village doctors are not systematically evaluated for TB infection or disease. We assessed prevalence and incidence of latent TB infection (LTBI) among village doctors in China.Methods and FindingsA longitudinal study was conducted in Inner Mongolia Autonomous Region. We administered a questionnaire on demographics and risk factors for TB exposure and disease; Tuberculin skin testing (TST) and QuantiFERON-TB Gold in-tube assay (QFT-GIT) was conducted at baseline and repeated 12 months later. We used a logistic regression model to calculate adjusted odds ratios (ORs) for risk factors for TST and QFT-GIT prevalence and incidence. At the time of follow up, 19.5% of the 880 participating village doctors had a positive TST and 46.0% had a positive QFT-GIT result. Factors associated with TST prevalence included having a BCG scar (OR = 1.45, 95%CI 1.03–2.04) and smoking (OR = 1.69, 95%CI 1.17–2.44). Risk factors associated with QFT-GIT prevalence included being male (OR = 2.17, 95%CI 1.63–2.89), below college education (OR=1.42, 95%CI 1.01–1.97), and working for ≥25 years as a village doctor (OR = 1.64, 95%CI 1.12–2.39). The annual incidence of LTBI was 11.4% by TST and 19.1% by QFT-GIT. QFT-GIT conversion was associated with spending 15 minutes or more per patient on average (OR = 2.62, 95%CI 1.39–4.97) and having BCG scar (OR = 0.53, 95%CI 0.28–1.00).ConclusionsPrevalence and incidence of LTBI among Chinese village doctors is high. TB infection control measures should be strengthened among village doctors and at village healthcare settings.