ProSAAS-Derived Peptides are Colocalized with Neuropeptide Y and Function as Neuropeptides in the Regulation of Food Intake

ProSAAS is the precursor of a number of peptides that have been proposed to function as neuropeptides. Because proSAAS mRNA is highly expressed in the arcuate nucleus of the hypothalamus, we examined the cellular localization of several proSAAS-derived peptides in the mouse hypothalamus and found that they generally colocalized with neuropeptide Y (NPY), but not α-melanocyte stimulating hormone. However, unlike proNPY mRNA, which is upregulated by food deprivation in the mediobasal hypothalamus, neither proSAAS mRNA nor proSAAS-derived peptides were significantly altered by 1–2 days of food deprivation in wild-type mice. Furthermore, while proSAAS mRNA levels in the mediobasal hypothalamus were significantly lower in Cpefat/fat mice as compared to wild-type littermates, proNPY mRNA levels in the mediobasal hypothalamus and in other subregions of the hypothalamus were not significantly different between wild-type and Cpefat/fat mice. Intracerebroventricular injections of antibodies to two proSAAS-derived peptides (big LEN and PEN) significantly reduced food intake in fasted mice, while injections of antibodies to two other proSAAS-derived peptides (little LEN and little SAAS) did not. Whole-cell patch clamp recordings of parvocellular neurons in the hypothalamic paraventricular nucleus, a target of arcuate NPY projections, showed that big LEN produced a rapid and reversible inhibition of synaptic glutamate release that was spike independent and abolished by blocking postsynaptic G protein activity, suggesting the involvement of a postsynaptic G protein-coupled receptor and the release of a retrograde synaptic messenger. Taken together with previous studies, these findings support a role for proSAAS-derived peptides such as big LEN as neuropeptides regulating food intake

Аналіз маркерів міжклітинної адгезії у хворих на плоскоклітинний рак орофарингеальної ділянки

The authors have carried out a study of the level of the expression of the markers of intercellular adhesion in patients with planocellular carcinoma of the оrоpharyngeal area in order to detect clinicomorphological connections and an analysis of their significance between the level of the expression of E-kadgerin and ß-katenin, metastasizing and efficiency of chemoradiotherapy. A diagnostic and a prognostic value of every marker in relation to regional metastasizing and the effect of treatment have been established.Проведено исследование уровня экспрессии маркеров межклеточной адгезии у больных плоскоклеточным раком орофарингеальной области для выявления клинико-морфологических связей и анализа их значимости между уровнем экспрессии Е-кадгерина и ß-катенина и метастазированием и эффективностью химиолучевого лечения. Установлено диагностическое значение, прогностическое значение каждого маркера относительно регионарного метастазирования и предсказательное относительно эффекта на проведенное химиолучевое лечение.Проведено дослідження рівня експресії маркерів міжклітинної адгезії у хворих на плоскоклітинний рак орофарингеальної ділянки для виявлення клінічно-морфологічних зв'язків та аналізу їх значимості між рівнем експресії Е-кадгерину і ß-катеніну, метастазуванням і ефективністю хіміопроменевого лікування. Встановлено діагностичне і прогностичне значення кожного маркера відносно регіонарного метастазування та ефекту лікування

Alterations of the Intracellular Peptidome in Response to the Proteasome Inhibitor Bortezomib

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Bortezomib is an antitumor drug that competitively inhibits proteasome beta-1 and beta-5 subunits. While the impact of bortezomib on protein stability is known, the effect of this drug on intracellular peptides has not been previously explored. A quantitative peptidomics technique was used to examine the effect of treating human embryonic kidney 293T (HEK293T) cells with 5-500 nM bortezomib for various lengths of time (30 minutes to 16 hours), and human neuroblastoma SH-SY5Y cells with 500 nM bortezomib for 1 hour. Although bortezomib treatment decreased the levels of some intracellular peptides, the majority of peptides were increased by 50-500 nM bortezomib. Peptides requiring cleavage at acidic and hydrophobic sites, which involve beta-1 and -5 proteasome subunits, were among those elevated by bortezomib. In contrast, the proteasome inhibitor epoxomicin caused a decrease in the levels of many of these peptides. Although bortezomib can induce autophagy under certain conditions, the rapid bortezomib-mediated increase in peptide levels did not correlate with the induction of autophagy. Taken together, the present data indicate that bortezomib alters the balance of intracellular peptides, which may contribute to the biological effects of this drug.81National Institutes of Health [R01 DA-004494]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)University of Sao Paulo [2011.1.9333.1.3]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)National Institutes of Health [R01 DA-004494]CNPq [559698/2009-7]University of Sao Paulo [2011.1.9333.1.3