Glutamylation regulates transport, specializes function, and sculpts the structure of cilia

Ciliary microtubules (MTs) are extensively decorated with post-translational modifications (PTMs), such as glutamylation of tubulin tails. PTMs and tubulin isotype diversity act as a “Tubulin Code” that regulates cytoskeletal stability and the activity of MT-associated proteins such as kinesins. We previously showed that, in C. elegans cilia, the deglutamylase CCPP-1 affects ciliary ultrastructure, localization of the TRP channel PKD-2 and the kinesin-3 KLP-6, and velocity of kinesin-2 OSM-3/KIF17, while a cell-specific α-tubulin isotype regulates ciliary ultrastructure, intraflagellar transport, and ciliary functions of extracellular vesicle (EV)-releasing neurons. Here, we examine the role of PTMs and the Tubulin Code in the cililary specialization of EV-releasing neurons using genetics, fluorescence microscopy, kymography, electron microscopy, and sensory behavioral assays. Although the C. elegans genome encodes five tubulin tyrosine ligase-like (TTLL) glutamylases, only ttll-11 specifically regulates PKD-2 localization in EV- releasing neurons. In EV-releasing cephalic male (CEM) cilia, TTLL-11 and the deglutamylase CCPP-1 regulate remodeling of 9+0 MT doublets into 18 singlet MTs. Balanced TTLL-11 and CCPP-1 activity fine-tunes glutamylation to control velocity of kinesin-2 OSM-3/KIF17 and kinesin-3 KLP-6 without affecting the IFT kinesin-II. TTLL-11 is transported by ciliary motors. TTLL-11 and CCPP-1 are also required for the ciliary function of releasing bioactive EVs, and TTLL-11 is itself a novel EV cargo. Therefore, MT glutamylation, as part of the tubulin code, controls ciliary specialization, ciliary motor-based transport, and ciliary EV release in a living animal. We suggest that cell-specific control of MT glutamylation may be a conserved mechanism to specialize the form and function of cilia

Effects of the aqueous extract of hyptis pectinata on liver regeneration after 70% partial hepatectomy preliminar results

O uso de plantas medicinais tem aumentado bastante na população mundial. O objetivo desta pesquisa é avaliar os efeitos do extrato aquoso das folhas da Hyptis pectinata, popularmente conhecida como "sambacaitá" ou "canudinho", sobre a regeneração hepática após hepatectomia parcial de 70%. Foram utilizados 24 ratos, divididos em 4 grupos: grupo OS, em que se realizou operação simulada e aplicação oral de água destilada por 4 dias; grupo OSD200, também submetido à laparotomia com manipulação do fígado e aplicação de 200 mg de extrato/Kg de animal durante o mesmo período; grupo HP, hepatectomizado a 70% após 4 dias de aplicação por via oral de água destilada; e grupo HPD200, hepatectomizado a 70% após 4 dias de administração de 200 mg extrato/Kg de animal. Foram dosadas fosfatase alcalina, bilirrubina total e as aminotransferases e estudou-se o estado III da função mitocondrial. O grupo OSD200, quando comparado ao OS, apresentou redução significativa da fosfatase alcalina. O grupo HPD200, em comparação ao HP, teve redução estatisticamente significativa no nível da AST e do estado III da função mitocondrial. _________________________________________________________________________________________ ABSTRACT: The use of medicinal plants has strongly increased by the world population. The objetive of this study is to assess the effects of the aqueous extract of Hyptis pectinata leaves, popularly known as "sambacaitá" or "canudinho", on liver regeneration after 70% partial hepatectomy. Twenty four rats were divided into 4 groups: group OS, submitted to sham operation and oral administration of distilled water during 4 days; group OSD200, also submitted to sham operation and ingestion of 200 mg of extract/Kg of animal for the same period of time; group HP, which underwent 70% hepatectomy after 4 days of distilled water administration; and group HPD200, which underwent 70% hepatectomy after 4 days of oral administration of 200 mg of extract/Kg of animal. Alkaline phosphatase, total bilirubin and the serum level of aminotransferases were measured and state III of mitochondrial respiratory activity was assessed. Group OSD200, when compared to OS, presented significant decrease of alcaline fosfatase. Group HPD200, when compared to HP, showed statistically significant decrease of AST level and state III respiratory process

Discovery of Samarium, Europium, Gadolinium, and Terbium Isotopes

Currently, thirty-four samarium, thirty-four europium, thirty-one gadolinium, and thirty-one terbium isotopes have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.Comment: To be published in At. Data Nucl. Data Table

A putative relay circuit providing low-threshold mechanoreceptive input to lamina I projection neurons via vertical cells in lamina II of the rat dorsal horn

Background: Lamina I projection neurons respond to painful stimuli, and some are also activated by touch or hair movement. Neuropathic pain resulting from peripheral nerve damage is often associated with tactile allodynia (touch-evoked pain), and this may result from increased responsiveness of lamina I projection neurons to non-noxious mechanical stimuli. It is thought that polysynaptic pathways involving excitatory interneurons can transmit tactile inputs to lamina I projection neurons, but that these are normally suppressed by inhibitory interneurons. Vertical cells in lamina II provide a potential route through which tactile stimuli can activate lamina I projection neurons, since their dendrites extend into the region where tactile afferents terminate, while their axons can innervate the projection cells. The aim of this study was to determine whether vertical cell dendrites were contacted by the central terminals of low-threshold mechanoreceptive primary afferents. Results: We initially demonstrated contacts between dendritic spines of vertical cells that had been recorded in spinal cord slices and axonal boutons containing the vesicular glutamate transporter 1 (VGLUT1), which is expressed by myelinated low-threshold mechanoreceptive afferents. To confirm that the VGLUT1 boutons included primary afferents, we then examined vertical cells recorded in rats that had received injections of cholera toxin B subunit (CTb) into the sciatic nerve. We found that over half of the VGLUT1 boutons contacting the vertical cells were CTb-immunoreactive, indicating that they were of primary afferent origin. Conclusions: These results show that vertical cell dendritic spines are frequently contacted by the central terminals of myelinated low-threshold mechanoreceptive afferents. Since dendritic spines are associated with excitatory synapses, it is likely that most of these contacts were synaptic. Vertical cells in lamina II are therefore a potential route through which tactile afferents can activate lamina I projection neurons, and this pathway could play a role in tactile allodynia

Neuronal circuitry for pain processing in the dorsal horn

Neurons in the spinal dorsal horn process sensory information, which is then transmitted to several brain regions, including those responsible for pain perception. The dorsal horn provides numerous potential targets for the development of novel analgesics and is thought to undergo changes that contribute to the exaggerated pain felt after nerve injury and inflammation. Despite its obvious importance, we still know little about the neuronal circuits that process sensory information, mainly because of the heterogeneity of the various neuronal components that make up these circuits. Recent studies have begun to shed light on the neuronal organization and circuitry of this complex region

Efeito do extrato aquoso da Hyptis pectinata na regeneração hepática após hepatectomia parcial em ratos

Objetivo: Este estudo foi realizado com o objetivo de verificar o efeito do extrato aquoso da Hyptis pectinata na regeneração hepática bem como nos níveis das enzimas séricas (AST, ALT e γ-GT) após hepatectomia parcial de 67% em ratos. Métodos: AST, ALT e γ-GT, foram determinadas pelo método cinético utilizando um espectrofotômetro (Modelo E2250- CELM). A regeneração hepática foi avaliada por imunohistoquímica (PCNA). Resultados: O pré-tratamento oral de 100 mg/ kg foi realizado durante 4 dias e causou aumento na regeneração hepática O pré-tratamento oral com 200 mg/kg diminuiu significativamente os níveis de AST quando comparado com o grupo submetido ao pré-tratamento com água destilada. As demais enzimas avaliadas não apresentaram diferenças quando comparadas entre os grupos estudados. Conclusão: O presente estudo mostra que o extrato aquoso da Hyptis pectinata, numa concentração de 100 mg/kg possui alguma atividade biológica estimulando a regeneração hepática e causando também um leve efeito hepatoprotetor numa concentração de 200 mg/kg. _________________________________________________________________________________________ ABSTRACT: Purpose: This study was carried out to assess the effects of the aqueous extract of Hyptis pectinata leaves on liver regeneration and on serum enzymes (AST, ALT and γ-GT) after 67% partial hepatectomy in rats. Methods: AST, ALT and γ-GT, were determined by conventional procedures using a spectrophotometer (Model E2250-CELM). Liver regeneration was evaluated by immunohistochemical staining for proliferating cell nuclear antigen (PCNA). Results:Oral pretreatment during 4 days at 100 mg/kg increased liver regeneration index. At 200 mg/kg, AST level was statistically decreased in comparison to the group submited to distilled water administration. The other enzymes assessed disclosed no difference when all groups were compared. Conclusion: The present study shows that the aqueous extract of Hyptis pectinata leaves contains some biological active principles that stimulate liver regeneration at 100 mg/kg and cause slight hepatic protection at 200 mg/kg