543 research outputs found

    Characterisation of l(3)IX-14, a novel mitotic mutant in Drosophila melanogaster

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    Does autonomous macrophage-driven inflammation promote alveolar damage in COVID-19?

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    SARS-CoV-2 has caused devastating effects with over 550 million infections by July 2022 and approximately 6.4 million deaths [1]. Societal and economic impacts will reverberate for years, with continuous evolution of SARS-CoV-2 as it persistently spreads through the human population as exemplified by reduced activity of vaccines and monoclonals against Omicron BA.4 or BA.5 subvariants [2]. A greater understanding of pathogenesis and more tailored therapeutic approaches are therefore essential

    Factors associated with profitability in pasture-based systems of milk production

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    peer-reviewedThe global dairy industry needs to reappraise the systems of milk production that are operated at farm level with specific focus on enhancing technical efficiency and competitiveness of the sector. The objective of this study was to quantify the factors associated with costs of production, profitability, and pasture use, and the effects of pasture use on financial performance of dairy farms using an internationally recognized representative database over an 8-yr period (2008 to 2015) on pasture-based systems. To examine the associated effects of several farm system and management variables on specific performance measures, a series of multiple regression models were developed. Factors evaluated included pasture use [kg of dry matter/ha and stocking rate (livestock units/ha)], grazing season length, breeding season length, milk recording, herd size, dairy farm size (ha), farmer age, discussion group membership, proportion of purchased feed, protein %, fat %, kg of milk fat and protein per cow, kg of milk fat and protein per hectare, and capital investment in machinery, livestock, and buildings. Multiple regression analysis demonstrated costs of production per hectare differed by year, geographical location, soil type, level of pasture use, proportion of purchased feed, protein %, kg of fat and protein per cow, dairy farm size, breeding season length, and capital investment in machinery, livestock, and buildings per cow. The results of the analysis revealed that farm net profit per hectare was associated with pasture use per hectare, year, location, soil type, grazing season length, proportion of purchased feed, protein %, kg of fat and protein per cow, dairy farm size, and capital investment in machinery and buildings per cow. Pasture use per hectare was associated with year, location, soil type, stocking rate, dairy farm size, fat %, protein %, kg of fat and protein per cow, farmer age, capital investment in machinery and buildings per cow, breeding season length, and discussion group membership. On average, over the 8-yr period, each additional tonne of pasture dry matter used increased gross profit by €278 and net profit by €173 on dairy farms. Conversely, a 10% increase in the proportion of purchased feed in the diet resulted in a reduction in net profit per hectare by €97 and net profit by €207 per tonne of fat and protein. Results from this study, albeit in a quota limited environment, have demonstrated that the profitability of pasture-based dairy systems is significantly associated with the proportion of pasture used at the farm level, being cognizant of the levels of purchased feed

    A pilot acoustic study of Modern Persian vowels in colloquial speech

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    While the current literature on Modern Persian (MP) shows heightened interest in its vowel inventory, a cogent synchronic account of Modern Persian vowels (MPV) has yet to be presented. Previous phonological descriptions of MPV presuppose a pairing system based on a historical length distinction that is still reflected in MP orthography: /i:, e/, /u:, o/, /ɒ:, æ/. A synchronic phonological analysis of MPV must be based on phonetic measurements; however, existing acoustic studies examine only formal speech, and thus do not reflect colloquial surface forms. Therefore, the goal of this investigation is to lay the groundwork for a comprehensive acoustic study of MPV that presupposes no pairings and is based on colloquial speech in a controlled prosodic environment. Vowel duration and first and second formants were measured using Praat for 90 CVC(C) monosyllables as pronounced phrase-finally in carrier sentences by two Tehrani native speakers: one male, one female. Results show that average durations for each vowel contradicted the traditional length-based pairings. Furthermore, features of the following phonological environment likely to affect vowel length – postvocalic consonant type, coda complexity (CVC vs. CVCC), and adherence to the Sonority Sequencing Principle in complex codas – had no notable effect. Results of formant measurements show the two non-high back vowels to be higher than expected, whereas the high back vowel was noticeably centralized

    Invadolysin: a novel, conserved metalloprotease links mitotic structural rearrangements with cell migration

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    The cell cycle is widely known to be regulated by networks of phosphorylation and ubiquitin-directed proteolysis. Here, we describe IX-14/invadolysin, a novel metalloprotease present only in metazoa, whose activity appears to be essential for mitotic progression. Mitotic neuroblasts of Drosophila melanogaster IX-14 mutant larvae exhibit increased levels of nuclear envelope proteins, monopolar and asymmetric spindles, and chromosomes that appear hypercondensed in length with a surrounding halo of loosely condensed chromatin. Zymography reveals that a protease activity, present in wild-type larval brains, is missing from homozygous tissue, and we show that IX-14/invadolysin cleaves lamin in vitro. The IX-14/invadolysin protein is predominantly found in cytoplasmic structures resembling invadopodia in fly and human cells, but is dramatically relocalized to the leading edge of migrating cells. Strikingly, we find that the directed migration of germ cells is affected in Drosophila IX-14 mutant embryos. Thus, invadolysin identifies a new family of conserved metalloproteases whose activity appears to be essential for the coordination of mitotic progression, but which also plays an unexpected role in cell migration

    Inhibition of cyclin-dependent kinase 9 downregulates cytokine production without detrimentally affecting human monocyte-derived macrophage viability

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    Cyclin-dependent kinase (CDK) inhibitor drugs (CDKi), such as R-roscovitine and AT7519, induce neutrophil apoptosis in vitro and enhance the resolution of inflammation in a number of in vivo models. This class of compounds are potential novel therapeutic agents that could promote the resolution of acute and chronic inflammatory conditions where neutrophil activation contributes to tissue damage and aberrant tissue repair. In this study we investigated CDKi effects on macrophage pro-inflammatory mediator production and viability. Treatment of human monocyte-derived macrophages (MDMs) with the CDKi AT7519 and R-roscovitine at concentrations that induce neutrophil apoptosis had no significant effect on control or LPS-activated MDM apoptosis and viability, and did not detrimentally affect MDM efferocytosis of apoptotic cells. In addition, enhanced efferocytosis, induced by the glucocorticoid dexamethasone, was also unaffected after a short time treatment with R-roscovitine. Macrophage cytokine responses to inflammatory stimuli are also of importance during inflammation and resolution. As a key target of CDKi, CDK9, is involved in protein transcription via the RNA polymerase II complex, we investigated the effect of CDKi drugs on cytokine production. Our data show that treatment with AT7519 significantly downregulated expression and release of key MDM cytokines IL-6, TNF, IL-10 and IL-1β, as well as markers of pro-inflammatory macrophage polarisation. R-Roscovitine was also able to downregulate inflammatory cytokine protein secretion from MDMs. Using siRNA transfection, we demonstrate that genetic knock-down of CDK9 replicates these findings, reducing expression and release of pro-inflammatory cytokines. Furthermore, overexpression of CDK9 in THP-1 cells can promote a pro-inflammatory phenotype in these cells, suggesting that CDK9 plays an important role in the inflammatory phenotype of macrophages. Overall, this study demonstrates that pharmacological and genetic targeting of CDK9 inhibits an inflammatory phenotype in human MDMs. As such these data indicate that CDK9 may be key to therapeutically targeting pro-inflammatory macrophage functions during chronic inflammation

    Loss of the integrin-activating transmembrane protein Fam38A (Piezo1) promotes a switch to a reduced integrin-dependent mode of cell migration

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    Lung cancer is one of the most common fatal diseases in the developed world. The disease is rarely cured by currently available therapies, with an overall survival rate of ∼10%. Characterizing novel proteins that offer crucial insights into the processes of lung tumour invasion and metastasis may therefore provide much-needed prognostic markers, and influence therapeutic strategies. Aberrant function of the integrin family of heterodimeric cell surface receptors is a common theme in cancer--investigation into novel integrin activity regulators may offer crucial insights into the processes of tumour invasion and metastasis and may reveal insights into potential therapeutic targets. We previously described that depletion of the novel multi-transmembrane domain protein Fam38A, located at the endoplasmic reticulum (ER), inactivates endogenous beta1 integrin affinity, reducing cell adhesion. We now show that depletion of Fam38A, also now known as Piezo1, causes anchorage independence and a switch to a reduced integrin-dependent mode of cell migration/invasion, a novel phenotype for this integrin-regulating protein. Normal lung epithelial cells show increased rates of migration by 2D time-lapse microscopy and increased capacity to invade into matrigel, despite having decreased integrin affinity. We confirm greatly depleted Fam38A expression in small cell lung cancer (SCLC) lines where a form of reduced integrin-dependent migration, i.e. amoeboid migration, is a known phenotype. We propose that loss of Fam38A expression may cause increased cell migration and metastasis in lung tumours
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