Dynamin and PTP-PEST cooperatively regulate Pyk2 dephosphorylation in osteoclasts

Bone loss is caused by the dysregulated activity of osteoclasts which degrade the extracellular bone matrix. The tyrosine kinase Pyk2 is highly expressed in osteoclasts, and mice lacking Pyk2 exhibit an increase in bone mass, in part due to impairment of osteoclast function. Pyk2 is activated by phosphorylation at Y402 following integrin activation, but the mechanisms leading to Pyk2 dephosphorylation are poorly understood. In the current study, we examined the mechanism of action of the dynamin GTPase on Pyk2 dephosphorylation. Our studies reveal a novel mechanism for the interaction of Pyk2 with dynamin, which involves the binding of Pyk2's FERM domain with dynamin's plextrin homology domain. In addition, we demonstrate that the dephosphorylation of Pyk2 requires dynamin's GTPase activity and is mediated by the tyrosine phosphatase PTP-PEST. The dephosphorylation of Pyk2 by dynamin and PTP-PEST may be critical for terminating outside-in integrin signaling, and for stabilizing cytoskeletal reorganization during osteoclast bone resorption

A palynostratigraphic study of the Umrer Coalfield of Wardha Basin, Maharashtra State, Central India and its putative correlation with Indian and other Gondwanan areas

The present work details the results of the palynological studies carried out in the Umrer Coalfield of Wardha Basin of Maharashtra State, Central India. The coalfield covers an area of 4 sq. km and is characterized by three coal seams designated as bottom, middle and top seams with partings. Statistical analysis of the palynomorphs from these sediments have revealed the dominance of radial monosaccate pollen grains of the genus Parasaccites and subdominance of non-striate bisaccate genus Scheuringipollenites in association with other typical early Permian taxa viz. Crucisaccites, Callumispora, Caheniasaccites, Brevitriletes, Tiwariasporis and Primuspollenites. This association characterizes the palynoflora of the upper Karharbari Formation of India on the basis of which the Umrer Coalfield has been assigned an early Permian late Sakmarian to early Artinskian age. It is further authenticated by the presence of the species Crucisaccites monoletus significant of the Karharbari Formation. Age deductions have also been made by correlations with similar assemblages from different basins in India and early Permian palynoflora from other Gondwanan continents some of which have been associated with radiometrically dated sediments.Este trabalho relata os resultados dos estudos palinológicos realizados na região carvoeira da Bacia de Wardha, no Estado de Maharashtra, Índia Central. A região carvoeira cobre uma área de 4 km2 e é caracterizada por três camadas de carvão designadas como camadas de base, meio e topo intercaladas com lâminas de sedimento. Análises estatísticas dos palinomorfos desses sedimentos tem evidenciado o domínio de grãos de pólen monossacados radiais do gênero Parasaccites e subdomínio de bissacados estriados do gênero Scheuringipollenites em associação com outros taxa típicos do Eopermiano, a saber: Crucisaccites, Callumispora, Caheniasaccites, Brevitriletes, Tiwariasporis e Primuspollenites. Esta associação caracteriza a palinoflora da Formação Karharbari superior, sugerindo ser a região carvoeira de Umrer de idade neossakmariana a eoartinskiana. Essa idade é confirmada pela presença da espécie Crucisaccites monoletus típica da Formação Karharbari. Deduções de idade tem também sido feitas por correlações com assembleias similares de diferentes bacias da Índia e de palinofloras eopermianas de outros continentes gondvânicos, alguns dos quais tem sido associados com sedimentos datados radiométricamente

O significado estratigráfico do Complexo Solenoide no Permiano do Gondwana

The Solenoid Complex comprises a fossil wood assemblage with stratigraphic distribution restricted to the middle-late Kungurian, present in Western (Irati Formation, Paraná Basin, Brazil) and Eastern (Upper Barakar Interval of the Indian basins) Gondwana. Its occurrence seems to be related to the adaptation of certain plant groups to paleoenvironmental stress in lowland niches of coastal areas subject to salinity variation. The disappearance of these forms in the latest Kungurian is probably linked to the cessation of these conditions, which is confirmed by the sedimentary record. The here designated "Solenoid Complex Zone" correlates with the acme in diversification of striate and taeniate patterns especially in bisacatte pollen grains, but also in monosacatte ones, reflecting important tectonically and climatically driven changes in the vegetational pattern. The waning icehouse stage during the Permian was an important factor to the development of similar vegetation patterns in Western and Eastern Gondwana in the latitudinal belt of 40° - 55°.O Complexo Solenoide compreende um conjunto de lenhos fósseis com distribuição estratigráfica restrita ao Kunguriano médio-superior, presente no Gondwana Ocidental (Formação Irati, Bacia do Paraná, Brasil) e Oriental (Intervalo Barakar Superior de bacias da Índia). A sua ocorrência parece estar relacionada à adaptação de determinados grupos vegetais ao estresse paleoambiental em terras baixas de áreas costeiras sujeitas a variações de salinidade. O desaparecimento dessas formas no topo do Kunguriano está provavelmente relacionado à cessação de tais condições, o que é confirmado pelo registro sedimentar. A "Zona do Complexo Solenoide" aqui designada correlaciona-se com o clímax na diversificação de padrões estriados e teniados principalmente em polens bissacados, mas também em monossacados, refletindo importantes modificações no padrão vegetacional relacionadas à evolução climática e a processos tectônicos. O declínio do estágio icehouse durante o Permiano foi um fator importante para o desenvolvimento de padrões florísticos similares no leste e oeste do Gondwana em uma faixa latitudinal entre 40° - 55°

Histone deacetylase expression patterns in developing murine optic nerve

BACKGROUND: Histone deacetylases (HDACs) play important roles in glial cell development and in disease states within multiple regions of the central nervous system. However, little is known about HDAC expression or function within the optic nerve. As a first step in understanding the role of HDACs in optic nerve, this study examines the spatio-temporal expression patterns of methylated histone 3 (K9), acetylated histone 3 (K18), and HDACs 1–6 and 8–11 in the developing murine optic nerve head. RESULTS: Using RT-qPCR, western blot and immunofluorescence, three stages were analyzed: embryonic day 16 (E16), when astrocyte precursors are found in the optic stalk, postnatal day 5 (P5), when immature astrocytes and oligodendrocytes are found throughout the optic nerve, and P30, when optic nerve astrocytes and oligodendrocytes are mature. Acetylated and methylated histone H3 immunoreactivity was co-localized in the nuclei of most SOX2 positive glia within the optic nerve head and adjacent optic nerve at all developmental stages. HDACs 1–11 were expressed in the optic nerve glial cells at all three stages of optic nerve development in the mouse, but showed temporal differences in overall levels and subcellular localization. HDACs 1 and 2 were predominantly nuclear throughout optic nerve development and glial cell maturation. HDACs 3, 5, 6, 8, and 11 were predominantly cytoplasmic, but showed nuclear localization in at least one stage of optic nerve development. HDACs 4, 9 and10 were predominantly cytoplasmic, with little to no nuclear expression at any time during the developmental stages examined. CONCLUSIONS: Our results showing that HDACs 1, 2, 3, 5, 6, 8, and 11 were each localized to the nuclei of SOX2 positive glia at some stages of optic nerve development and maturation and extend previous reports of HDAC expression in the aging optic nerve. These HDACs are candidates for further research to understand how chromatin remodeling through acetylation, deacetylation and methylation contributes to glial development as well as their injury response

Megakaryocytes Regulate Expression of Pyk2 Isoforms and Caspase-mediated Cleavage of Actin in Osteoblasts

The proliferation and differentiation of osteoblast (OB) precursors are essential for elaborating the bone-forming activity of mature OBs. However, the mechanisms regulating OB proliferation and function are largely unknown. We reported that OB proliferation is enhanced by megakaryocytes (MKs) via a process that is regulated in part by integrin signaling. The tyrosine kinase Pyk2 has been shown to regulate cell proliferation and survival in a variety of cells. Pyk2 is also activated by integrin signaling and regulates actin remodeling in bone-resorbing osteoclasts. In this study, we examined the role of Pyk2 and actin in the MK-mediated increase in OB proliferation. Calvarial OBs were cultured in the presence of MKs for various times, and Pyk2 signaling cascades in OBs were examined by Western blotting, subcellular fractionation, and microscopy. We found that MKs regulate the temporal expression of Pyk2 and its subcellular localization. We also found that MKs regulate the expression of two alternatively spliced isoforms of Pyk2 in OBs, which may regulate OB differentiation and proliferation. MKs also induced cytoskeletal reorganization in OBs, which was associated with the caspase-mediated cleavage of actin, an increase in focal adhesions, and the formation of apical membrane ruffles. Moreover, BrdU incorporation in MK-stimulated OBs was blocked by the actin-polymerizing agent, jasplakinolide. Collectively, our studies reveal that Pyk2 and actin play an important role in MK-regulated signaling cascades that control OB proliferation and may be important for therapeutic interventions aimed at increasing bone formation in metabolic diseases of the skeleton

Coníferas pensilvanianas da tafoflora interglacial de Monte Mor, Grupo Itararé, São Paulo, Brasil: as mais antigas da Bacia do Paraná

A macroflora pré-glossopterídea do sítio Volpe, em Monte Mor (Estado de São Paulo), depositou-se, durante um interglacial do Grupo Itararé. Essa ocorrência caracteriza a Associação Paranocladus-Ginkgophyllum-Brasilodendron da porção médio‑basal do Grupo Itararé aflorante no NE da bacia do Paraná. Corresponde à associação macroflorística argentina Fitozona Krauselcladus-Asterotheca (ex-Zona Intervalo) e seu conteúdo palinoflorístico pertence à Palinozona Crucisaccites monoletus (Kasimoviano a Gzheliano). As coníferas dessa associação estão representadas por macro e microfósseis e registram o nível mais inferior de ocorrência do grupo na bacia. São impressões e compressões de ramos folhosos de Paranocladus dusenii Florin e Buriadia heterophylla (Feistmantel) Seward and Sahni emend. Singh e de sementes platispérmicas do gênero Paranospermum. Estudos cuticulares possibilitaram relacionar a presença de Paranocladus dusenii com as sementes platispérmicas Paranospermum cambuiense Ricardi-Branco e detectar uma nova espécie de Paranospermum. Estudos palinológicos anteriores, neste nível, permitiram identificar a presença de grãos de pólen afins às gimnospermas (coniferales, ginkgoales e pteridospermales) compreendendo formas monossacadas e bissacadas dos gêneros: Cannanoropolis, Plicatipollenites, Potonieisporites e Caheniasaccites, indicando já certa diversidade do grupo no Pensilvaniano. A associação das coníferas e Ginkgophyllum representaria uma comunidade arbórea mesoxerofítica. A abundância de seu material fragmentado, na assembleia fitofossilífera, sugere aloctonia com transporte em direção a uma planície deltaica onde associa-se a material parautoctone. A matriz fossilífera arenosa, sobreposta ao carvão, também evidencia um agente transportador de maior energia.The pre-glossopterid macroflora from the Volpe Ranch, in Monte Mor (State of São Paulo), was deposited during an interglacial context of the Itararé Group. It is characterized by the Paranocladus-Ginkgophyllum-Brasilodendron Association and is included in the middle-basal part of the Itararé Group outcrop, in the NE of the Paraná Basin. It is similar to the Argentine macrofloristic association Krauselcladus-Asterotheca Phytozone (ex-Interval Zone) and its palynofloristic contents belong to the Crucisaccites monoletus Palynozone (Kasimovian to Gzhelian). The conifers in this assemblage are represented by macro and microfossils and record the first level of occurrence of conifers in the basin. They are documented by leafy branches impressions and compressions of Paranocladus dusenii Florin and Buriadia heterophylla (Feistmantel) Seward and Sahni emend. Singh, and platyspermic seeds of the genus Paranospermum. Cuticular studies allowed to correlate the presence of Paranocladus dusenii with the platyspermic seeds Paranospermum cambuiense Ricardi-Branco and to identify a new species of Paranospermum as well. Previous palynological studies in this level led to the recognition of some pollen grains affinis to the gymnosperms (conifers, ginkgoaleans and pteridospermales) comprising monosaccate and bisaccate forms allocated to the genera Cannanoropollis, Plicatipollenites, Potonieisporites and Caheniasaccites indicating certain diversity of conifers as early as in Pennsylvanian. The association of conifers and Ginkgophyllum represents a mesoxerophytic tree community. The abundance of their fragmented material in the taphofloral assemblage suggests allochthonous origin transported toward a deltaic plain which were associated to a parautochthonous origin material. Their fossiliferous sandy matrix overlying the coal also suggests a higher energy agent of transport

Floristic similarities of the Artinskian Siderópolis Member macroflora, Rio Bonito formation (Paraná Basin, Brazil) with Cisuralian paleofloras of India

This contribution focuses on the relationship between the Siderópolis Member paleoflora and Indian Gondwanan paleofloras, especially with those of the Cisuralian stages, thus providing additional criteria for the correlation of Western and Eastern Gondwanan coal successions in the lower Permian interval. Despite the large number of species in common with the Karharbari Stage (Sakmarian) flora, the Siderópolis paleoflora exhibits a higher percentage and diversification of the genus Glossopteris, which is less expressive in the Karharbari Stage floras, while the declining Gangamopteris-Noeggerathiopsis complex in Siderópolis Member paleoflora still dominates the associations of Karharbari Stage. However, the floristic composition of the lower level of the Barakar Stage (Artinskian), despite having fewer species in common with the Siderópolis paleoflora, exhibits the characters of the latter vis-à-vis the dominance and diversity of the genus Glossopteris over the Gangamopteris‑Noeggerathiopsis complex, which decreases both in diversity as well as in abundance in the lower Barakar, similar to what occurs in the Brazilian paleoflora. The decline of the icehouse stage and the similar latitudinal position of the Gondwanan regions compared in the present study seem to have acted as important factors to the development of similar vegetation patterns in coal floras from Western (Brazilian) and Eastern (Indian) Gondwana during the Artinskian.Esta contribuição visa à comparação entre a paleoflora do Membro Siderópolis e as paleofloras dos andares cisuralianos das bacias gondvânicas indianas, oferecendo assim critérios adicionais para a correlação das sucessões carvoeira gondvânicas ocidentais e orientais, no intervalo do Permiano inferior. Apesar do grande número de espécies em comum com as floras do Andar Karharbari (Sakmariano), a paleoflora Siderópolis apresenta maior percentagem e diversificação do gênero Glossopteris, menos expressivas nas floras do Andar Karharbari, enquanto o complexo Gangamopteris-Noeggerathiopsis, declinante na paleoflora do Membro Siderópolis, ainda domina nas associações do referido andar indiano. Entretanto, a composição florística do nível inferior do Andar Barakar (Artinskiano), apesar de apresentar menos espécies em comum com a paleoflora Siderópolis, caracteriza-se pelo domínio e diversidade do gênero Glossopteris sobre o complexo Gangamopteris-Noeggerathiopsis, que diminui tanto em diversidade como em abundância no Barakar inferior, semelhante ao que ocorre na paleoflora brasileira aqui estudada. O declínio do estágio icehouse e a posição latitudinal semelhante das regiões gondvânicas aqui comparadas, durante o Artinskiano, teriam atuado como fatores importantes no desenvolvimento de padrões de vegetação similares nas floras geradoras de carvões no Gondwana Ocidental (Brasil) e no Oriental (Índia)

Similaridades entre associações de cistos de dinoflagelados, K/Pc nos proto-oceanos Atlântico Sul e Índico

Nesta contribuição analisamos a composição de assembleias de cistos de dinoflagelados encontrados em sedimentos da Bacia de Pelotas, sul do Brasil, durante o intervalo Cretáceo Superior - Paleoceno, com o objetivo de produzir uma primeira comparação com a Índia e outros continentes pertencentes ao Gondwana tais como América do Sul (Argentina e Uruguai), África (Nigéria e Oeste de Gana), Antártica, Austrália e Nova Zelândia. Um total de 13 espécies foi identificado, dentre as quais se observaram táxons endêmicos e cosmopolitas, que permitiram o reconhecimento de paleoambientes que variaram de nerítico raso, lagunar ou pantanoso costeiro, com deposição de sedimentos em condições anóxicas. A presente análise de similaridade entre essas associações de cistos de dinoflagelados permitiu o estabelecimento da distribuição paleobiogeográfica para a Bacia de Pelotas.In this contribution we present the composition of the Late Cretaceous / Paleocene dinoflagellate cyst assemblages found in the Pelotas Basin, southern Brazil in order to provide a first paleobiogeographical comparison between this location, India and other former Gondwana continents: South America (Argentina and Uruguay), Africa (Nigeria and Western Ghana), Antarctica, Australia, and New Zealand. A total of 13 taxa, some endemic and other cosmopolitan were identified. The paleoenvironment of the Gondwana former members basins, as previously presented and attested by the dinoflagellate cysts are marginal marine nearshore, varying from neritic to shallow neritic and lagoonal or coastal swamps, which permitted the deposition of sediments in anoxic marine conditions. The present analysis of similarity between K/Pc dinoflagellate cyst associations allowed the establishment of paleobiogeographic distribution

The Artinskian Siderópolis Member macroflora, Rio Bonito Formation and its stratigraphical correlation with other early Permian macrofloras of Paraná Basin, Brazil

An overview of the composition of the paleoflora preserved in clay-siltstones of the Siderópolis Member, Rio Bonito Formation is presented in order to establish phytostratigraphical comparisons with other Late Pennsylvanian and Cisuralian paleofloras of the Paraná Basin. The Rio Bonito Formation, the most important of the coal bearing lithostratigraphic units of the Paraná Basin belongs to the Gondwana I Supersequence (Pennsylvanian-Early Triassic). The Siderópolis paleoflora occurs in the uppermost layers of coal of Rio Bonito Formation in Santa Catarina coalfield in four distinct localities of the State of Santa Catarina: Lauro Muller, Criciúma, São Marcos and Treviso. In this paleoflora the glossopterid leaves predominate with an evident dominance of the genus Glossopteris over Gangamopteris, followed by Cordaitalean leaves (Noeggerathiopsis) and seeds (Cordaicarpus, Samaropsis, Cornucarpus). Sterile fronds are common and few are fertile (Sphenopteris, Pecopteris, Ponsotheca and Notoangaridium). Pteridosperm reproductive structures (Arberia, Arberiopsis, Ottokaria) are not frequent and branches of conifers (Brasilocladus, Buriadia) are rare. Concerning other paleofloras of the basin, the Siderópolis paleoflora is distinguished by high diversity and many exclusive taxa showing only few similarities with some paleofloras registered in Rio Grande do Sul, occurring in outcrops of the Rio Bonito Formation such as Morro do Papaléo (upper section) and Quitéria. The differences may reflect an upper stratigraphic position, but may also indicate differences in sedimentation and / or in paleoecological conditions.Apresenta-se aqui uma síntese da composição da paleoflora preservada em siltitos argilosos do Membro Siderópolis, Formação Rio Bonito tendo como objetivo estabelecer comparações fitoestratigráficas com outras paleofloras neopensilvanianas e cisuralianas da Bacia do Paraná. A Formação Rio Bonito, a mais importante das unidades litoestratigráficas portadoras de carvão da Bacia do Paraná, pertence à supersequência Gondwana I (Pensilvaniano-Eotriássico). A paleoflora Siderópolis ocorre nas camadas de carvão mais superiores da Formação Rio Bonito na região carvoeira de Santa Catarina, em quatro áreas distintas do Estado de Santa Catarina: Lauro Muller, Criciúma, São Marcos e Treviso. Na paleoflora, as folhas de glossopterídeas predominam com um evidente domínio do gênero Glossopteris sobre Gangamopteris, seguido por folhas cordaitaleanas (Noeggerathiopsis) e sementes (Cordaicarpus, Samaropsis, Cornucarpus). Frondes estéreis são comuns havendo poucas férteis (Sphenopteris, Pecopteris, Ponsotheca, Notoangaridium). Estruturas reprodutivas pteridospérmicas  (Arberia, Arberiopsis, Ottokaria) e ramos de coníferas (Brasilocladus, Buriadia) são raros. Em relação a outras paleofloras da bacia, a de Siderópolis distingue-se por apresentar diversidade mais alta e muitos táxons exclusivos mostrando apenas umas poucas semelhanças com algumas paleofloras registradas no Rio Grande do Sul, ocorrendo em afloramentos do Rio Bonito tais como Morro do Papaléo (porção superior) e Quitéria. Essas diferenças podem refletir uma posição estratigráfica superior, mas pode também indicar diferenças em condições de sedimentação e / ou paleoecológicas