Insights into the Molecular Mechanisms of the Anti-Atherogenic Actions of Flavonoids in Normal and Obese Mice

Obesity is a major and independent risk factor for cardiovascular disease and it is strongly associated with the development of dyslipidemia, insulin resistance and type 2 diabetes. Flavonoids, a diverse group of polyphenol compounds of plant origin widely distributed in human diet, have been reported to have numerous health benefits, although the mechanisms underlying these effects have remained obscure. We analyzed the effects of chronic dietary supplementation with flavonoids extracted from cranberry (FLS) in normal and obese C57/BL6 mice compared to mice maintained on the same diets lacking FLS. Obese mice supplemented with flavonoids showed an amelioration of insulin resistance and plasma lipid profile, and a reduction of visceral fat mass. We provide evidence that the adiponectin-AMPK pathway is the main mediator of the improvement of these metabolic disorders. In contrast, the reduced plasma atherogenic cholesterol observed in normal mice under FLS seems to be due to a downregulation of the hepatic cholesterol synthesis pathway. Overall, we demonstrate for the first time that the molecular mechanisms underlying the beneficial effects of flavonoids are determined by the metabolic state

SYNTHESIS AND ANTIPROLIFERATIVE ACTIVITY OF NOVEL HYDRAZONE DERIVATIVES

A series of N6 substituted hydrazones derived from adenosine and 3'-C-methyladenosine (3'-MeAdo) was prepared in search for potential novel antitumor agents. The stereochemistry of these compounds was established by means of NMR spectroscopy and the antiproliferative activity was determined in a panel of human tumor cell lines in vitro. INTRODUCTION, RESULTS AND DISCUSSION, CONCLUSION Despite recent progress in tumor therapy, the majority of solid tumors are currently not curable by chemotherapy. Half of all cancer patients fail to respond to chemotherapy or relapse from the initial response and ultimately die from their metastatic disease. Recently, the clinical outcome of cancer patients has improved dramatically with combination chemotherapy, and today anticancer research is centering on developing targeted and individualized therapies. Even so, current treatments often do not completely rid patients of their cancers and cancer cells can become resistant to various chemotherapeutic agents directed at them. Thus significant challenges remain and there is the urgency to develop novel chemotherapeutic agents for treatment of some cancer types that can become refractory and/or show little responsiveness to current chemotherapy (e.g., colon, prostate, ovarian, and renal cancer, non-small cell lung carcinoma, CNS cancers, and melanoma). Ribonucleotide reductase (RR), a critical enzyme for the synthesis of deoxyribonucleotides and cell division, is over-expressed in rapidly dividing cancer cells, making it an im-portant target for cancer therapy. Recently, we reported that 3'-C-methyladenosine (3'-MeAdo) is a mechanism-based RR inhibitor endowed with a significant antitumor activity against a panel of human leukemia and carcinoma cell lines [1,2]. Among the N6-modified adenosine analogues, 6-hydrazinopurine-riboside has recently been reported by us to be a potent mutagenic agent acting as inhibitor of human RR, possibly by scavenging tyrosyl free radicals involved in the reduction of nucleoside diphosphates [3]. We now report on the synthesis and antitumor activity of a series of adenosine and 3'-C-methyladenosine derivatives substituted at N6 with methyl and pyridyl hydrazones. The stereochemistry of these compounds was established to be E by means of NMR spectroscopy. The antiproliferative activity of the substituted purine nucleosides against a panel of human tumor cell lines will be presented. REFERENCES 1. Franchetti, P., Cappellacci, L., Pasqualini, M., Petrelli, R., Vita, P., Jayaram, H.N., Horvath, Z., Szekeres, T., Grifantini, M. J. Med. Chem. 2005, 48, 4983-4989. 2. Cappellacci, L., Franchetti, P., Vita, P., Petrelli, R., Lavecchia, A., Jayaram, H.N., Saiko, P., Graser,G., Szekeres, T., Grifantini M. J. Med. Chem. 2008, 51, 4260-4269. 3. Cappellacci, L., Petrelli, R., Franchetti, P., Vita, P., Kusumanchi, P., Kumar, M., Jayaram, H.N., Zhou, B., Yun Yen, Y., Grifantini, M. Eur. J. Med. Chem. 2011, 46, 1499-1504

The transcriptional response to the olive fruit fly (Bactrocera oleae) reveals extended differences between tolerant and susceptible olive (Olea europaea L.) varieties

The olive fruit fly Bactrocera oleae (Diptera: Tephritidae) is the most devastating pest of cultivated olive (Olea europaea L.). Intraspecific variation in plant resistance to B. oleae has been described only at phenotypic level. In this work, we used a transcriptomic approach to study the molecular response to the olive fruit fly in two olive cultivars with contrasting level of susceptibility. Using next-generation pyrosequencing, we first generated a catalogue of more than 80,000 sequences expressed in drupes from approximately 700k reads. The assembled sequences were used to develop a microarray layout with over 60,000 olive-specific probes. The differential gene expression analysis between infested (i.e. with II or III instar larvae) and control drupes indicated a significant intraspecific variation between the more tolerant and susceptible cultivar. Around 2500 genes were differentially regulated in infested drupes of the tolerant variety. The GO annotation of the differentially expressed genes implies that the inducible resistance to the olive fruit fly involves a number of biological functions, cellular processes and metabolic pathways, including those with a known role in defence, oxidative stress responses, cellular structure, hormone signalling, and primary and secondary metabolism. The difference in the induced transcriptional changes between the cultivars suggests a strong genetic role in the olive inducible defence, which can ultimately lead to the discovery of factors associated with a higher level of tolerance to B. oleae

Consensus molecular environment of schizophrenia risk genes in coexpression networks shifting across age and brain regions

Schizophrenia is a neurodevelopmental brain disorder whose genetic risk is associated with shifting clinical phenomena across the life span. We investigated the convergence of putative schizophrenia risk genes in brain coexpression networks in postmortem human prefrontal cortex (DLPFC), hippocampus, caudate nucleus, and dentate gyrus granule cells, parsed by specific age periods (total N = 833). The results support an early prefrontal involvement in the biology underlying schizophrenia and reveal a dynamic interplay of regions in which age parsing explains more variance in schizophrenia risk compared to lumping all age periods together. Across multiple data sources and publications, we identify 28 genes that are the most consistently found partners in modules enriched for schizophrenia risk genes in DLPFC; twenty-three are previously unidentified associations with schizophrenia. In iPSC-derived neurons, the relationship of these genes with schizophrenia risk genes is maintained. The genetic architecture of schizophrenia is embedded in shifting coexpression patterns across brain regions and time, potentially underwriting its shifting clinical presentation

Targeted and selective knockout of the TLQP-21 neuropeptide unmasks its unique role in energy homeostasis

Objective: Pro-peptide precursors are processed into biologically active peptide hormones or neurotransmitters, each playing an essential role in physiology and disease. Genetic loss of function of a pro-peptide precursor results in the simultaneous ablation of all biologically-active peptides within that precursor, often leading to a composite phenotype that can be difficult to align with the loss of specific peptide components. Due to this biological constraint and technical limitations, mice carrying the selective ablation of individual peptides encoded by pro-peptide precursor genes, while leaving the other peptides unaffected, have remained largely unaddressed. Methods: We developed and characterized a mouse model carrying the selective knockout of the TLQP-21 neuropeptide (ΔTLQP-21) encoded by the Vgf gene. To achieve this goal, we used a knowledge-based approach by mutating a codon in the Vgf sequence leading to the substitution of the C-terminal Arginine of TLQP-21, which is the pharmacophore as well as an essential cleavage site from its precursor, into Alanine (R21→A). Results: We provide several independent validations of this mouse, including a novel in-gel digestion targeted mass spectrometry identification of the unnatural mutant sequence, exclusive to the mutant mouse. ΔTLQP-21 mice do not manifest gross behavioral and metabolic abnormalities and reproduce well, yet they have a unique metabolic phenotype characterized by an environmental temperature-dependent resistance to diet-induced obesity and activation of the brown adipose tissue. Conclusions: The ΔTLQP-21 mouse line can be a valuable resource to conduct mechanistic studies on the necessary role of TLQP-21 in physiology and disease, while also serving as a platform to test the specificity of novel antibodies or immunoassays directed at TLQP-21. Our approach also has far-reaching implications by informing the development of knowledge-based genetic engineering approaches to generate selective loss of function of other peptides encoded by pro-hormones genes, leaving all other peptides within the pro-protein precursor intact and unmodified