66 research outputs found

    Changes in the microsomal proteome of tomato fruit during ripening

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    The variations in the membrane proteome of tomato fruit pericarp during ripening have been investigated by mass spectrometry-based label-free proteomics. Mature green (MG30) and red ripe (R45) stages were chosen because they are pivotal in the ripening process: MG30 corresponds to the end of cellular expansion, when fruit growth has stopped and fruit starts ripening, whereas R45 corresponds to the mature fruit. Protein patterns were markedly different: among the 1315 proteins identified with at least two unique peptides, 145 significantly varied in abundance in the process of fruit ripening. The subcellular and biochemical fractionation resulted in GO term enrichment for organelle proteins in our dataset, and allowed the detection of low-abundance proteins that were not detected in previous proteomic studies on tomato fruits. Functional annotation showed that the largest proportion of identified proteins were involved in cell wall metabolism, vesicle-mediated transport, hormone biosynthesis, secondary metabolism, lipid metabolism, protein synthesis and degradation, carbohydrate metabolic processes, signalling and response to stress

    The role of histone lysine methylation in the response of mammalian cells to Ionizing radiation

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    Eukaryotic genomes are wrapped around nucleosomes and organized into different levels of chromatin structure. Chromatin organization has a crucial role in regulating all cellular processes involving DNA-protein interactions, such as DNA transcription, replication, recombination and repair. Histone post-translational modifications (HPTMs) have a prominent role in chromatin regulation, acting as a sophisticated molecular code, which is interpreted by HPTM-specific effectors. Here, we review the role of histone lysine methylation changes in regulating the response to radiation-induced genotoxic damage in mammalian cells. We also discuss the role of histone methyltransferases (HMTs) and histone demethylases (HDMs) and the effects of the modulation of their expression and/or the pharmacological inhibition of their activity on the radio-sensitivity of different cell lines. Finally, we provide a bioinformatic analysis of published datasets showing how the mRNA levels of known HMTs and HDMs are modulated in different cell lines by exposure to different irradiation conditions

    Depletion of ATP-citrate lyase (ATPCL) affects chromosome integrity without altering histone acetylation in Drosophila mitotic cells

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    The Citrate Lyase (ACL) is the main cytosolic enzyme that converts the citrate exported from mitochondria by the SLC25A1 carrier in Acetyl Coenzyme A (acetyl-CoA) and oxaloacetate. Acetyl-CoA is a high-energy intermediate common to a large number of metabolic processes including protein acetylation reactions. This renders ACL a key regulator of histone acetylation levels and gene expression in diverse organisms including humans. We have found that depletion of Drosophila ATPCL, the fly ortholog of human ACL, reduced levels of Acetyl CoA but, unlike its human counterpart, does not affect global histone acetylation and gene expression. Nevertheless, reduced ATPCL levels caused evident, although moderate, mitotic chromosome breakage suggesting that this enzyme plays a partial role in chromosome stability. These defects did not increase upon X-ray irradiation, indicating that they are not dependent on an impairment of DNA repair. Interestingly, depletion of ATPCL drastically increased the frequency of chromosome breaks associated to mutations in scheggia, which encodes the ortholog of the mitochondrial citrate carrier SLC25A1 that is also required for chromosome integrity and histone acetylation. Our results indicate that ATPCL has a dispensable role in histone acetylation and prevents massive chromosome fragmentation when citrate efflux is altered

    The RNA helicase DDX5 cooperates with EHMT2 to sustain alveolar rhabdomyosarcoma growth

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    Rhabdomyosarcoma (RMS) is the most common soft-tissue sarcoma of childhood characterized by the inability to exit the proliferative myoblast-like stage. The alveolar fusion positive subtype (FP-RMS) is the most aggressive and is mainly caused by the expression of PAX3/7-FOXO1 oncoproteins, which are chal-lenging pharmacological targets. Here, we show that the DEAD box RNA helicase 5 (DDX5) is overexpressed in alveolar RMS cells and that its depletion and pharmacological inhibition decrease FP-RMS viability and slow tumor growth in xenograft models. Mechanistically, we provide evidence that DDX5 functions upstream of the EHMT2/AKT survival signaling pathway, by directly interacting with EHMT2 mRNA, modulating its sta-bility and consequent protein expression. We show that EHMT2 in turns regulates PAX3-FOXO1 activity in a methylation-dependent manner, thus sustaining FP-RMS myoblastic state. Together, our findings identify another survival-promoting loop in FP-RMS and highlight DDX5 as a potential therapeutic target to arrest RMS growth

    Neuroserpin polymers cause oxidative stress in a neuronal model of the dementia FENIB

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    The serpinopathies are human pathologies caused by mutations that promote polymerisation and intracellular deposition of proteins of the serpin superfamily, leading to a poorly understood cell toxicity. The dementia FENIB is caused by polymerisation of the neuronal serpin neuroserpin (NS) within the endoplasmic reticulum (ER) of neurons. With the aim of understanding the toxicity due to intracellular accumulation of neuroserpin polymers, we have generated transgenic neural progenitor cell (NPC) cultures from mouse foetal cerebral cortex, stably expressing the control protein GFP (green fluorescent protein), or human wild type, G392E or delta NS. We have characterised these cell lines in the proliferative state and after differentiation to neurons. Our results show that G392E NS formed polymers that were mostly retained within the ER, while wild type NS was correctly secreted as a monomeric protein into the culture medium. Delta NS was absent at steady state due to its rapid degradation, but it was easily detected upon proteasomal block. Looking at their intracellular distribution, wild type NS was found in partial co-localisation with ER and Golgi markers, while G392E NS was localised within the ER only. Furthermore, polymers of NS were detected by ELISA and immunofluorescence in neurons expressing the mutant but not the wild type protein. We used control GFP and G392E NPCs differentiated to neurons to investigate which cellular pathways were modulated by intracellular polymers by performing RNA sequencing. We identified 747 genes with a significant upregulation (623) or downregulation (124) in G392E NS-expressing cells, and we focused our attention on several genes involved in the defence against oxidative stress that were up-regulated in cells expressing G392E NS (Aldh1b1, Apoe, Gpx1, Gstm1, Prdx6, Scara3, Sod2). Inhibition of intracellular anti-oxidants by specific pharmacological reagents uncovered the damaging effects of NS polymers. Our results support a role for oxidative stress in the cellular toxicity underlying the neurodegenerative dementia FENIB

    Transcriptional Response of Human Neurospheres to helper-dependent CAV-2 vectors involves the modulation of DNA damage response, microtubule and centromere gene groups

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    Brain gene transfer using viral vectors will likely become a therapeutic option for several disorders. Helper-dependent (HD) canine adenovirus type 2 vectors (CAV-2) are well suited for this goal. These vectors are poorly immunogenic, efficiently transduce neurons, are retrogradely transported to afferent structures in the brain and lead to long-term transgene expression. CAV-2 vectors are being exploited to unravel behavior, cognition, neural networks, axonal transport and therapy for orphan diseases. With the goal of better understanding and characterizing HD-CAV-2 for brain therapy, we analyzed the transcriptomic modulation induced by HD-CAV-2 in human differentiated neurospheres derived from midbrain progenitors. This 3D model system mimics several aspects of the dynamic nature of human brain. We found that differentiated neurospheres are readily transduced by HDCAV- 2 and that transduction generates two main transcriptional responses: a DNA damage response and alteration of centromeric and microtubule probes. Future investigations on the biochemistry of processes highlighted by probe modulations will help defining the implication of HD-CAV-2 and CAR receptor binding in enchaining these functional pathways. We suggest here that the modulation of DNA damage genes is related to viral DNA, while the alteration of centromeric and microtubule probes is possibly enchained by the interaction of the HD-CAV-2 fibre with CAR

    Transcriptional modulations induced by proton irradiation in mice skin in function of adsorbed dose and distance

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    Hadron therapy by proton beams represents an advanced anti-cancer strategy due to its highly localized dose deposition allowing a greater sparing of normal tissue and/or organs at risk compared to photon/electron radiotherapy. However, it is not clear to what extent non-targeted effects such as transcriptional modulations produced along the beamline may diffuse and impact the surrounding tissue. In this work, we analyze the transcriptome of proton-irradiated mouse skin and choose two biomarker genes to trace their modulation at different distances from the beam's target and at different doses and times from irradiation to understand to what extent and how far it may propagate, using RNA-Seq and quantitative RT-PCR. In parallel, assessment of lipids alteration is performed by FTIR spectroscopy as a measure of tissue damage. Despite the observed high individual variability of expression, we can show evidence of transcriptional modulation of two biomarker genes at considerable distance from the beam's target where a simulation system predicts a significantly lower adsorbed dose. The results are compatible with a model involving diffusion of transcripts or regulatory molecules from high dose irradiated cells to distant tissue's portions adsorbing a much lower fraction of radiation

    Pengaruh Pemberian Bunga Rosella Terhadap Perubahan Tekanan Darah Penderita Hipertensi Dengan Terapi Captopril Di Desa Kamiwangi Kecamatan Toili Barat Kabupaten Luwuk Banggai

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    Hypertension is a cardiovasculer disturbance which is mostly founded in society. in healing hypertension, it needs continually Treatments. Rosella flower is a plant that has many good Components to heal hypertension. This research uses Quasy experiment design with control group. the amout of population in this research are 40 people. The method in taking sample uses purposive sampling and it got 30 respondents as the sample. The information of blood pressure was taken from the clients by using spygmomanometer, then it was displayed in table and processed by using SPSS program (statistic program for society science), used coupling T test, uncoupling T test with interpretation level 95%(a<0.05). The result of the research shows that the hypertension patients with captopril therapy which were given boiled dry rosella, got faster reduction of blood pressure after 2 hours than the hypertension patients with only captopril therapy. By using coupling T test, p-value was 0,00 . With mean value of the difference of reduction of sistolik blood pressure on the first day in intervention group was 28 mmHg while the control group was 11mmHg. on the second day, the reduction of sistolik blood pressure in intervention group was 13,33 l, and for control group, it was 5 mmHg. The diastolic blood pressure on the first day, the mean of the reduction of blood pressure in intervention group was 14mmHg while in control group was 6mmHg. On the second day, the mean of sistolic blood pressure in intervention group was 6 mmHg, and 2mmHg for control group. Key words: hypertension, rosella flower, captopril therapy Hipertensi merupakan penyakit gangguan kardiovaskuler. Bunga rosella adalah tumbuhan herbal untuk mengobati hipertensi. Tujuan penelitian melihat pengaruh bunga rosella terhadap tekanan darah penderita hipertensi dengan terapi captopril. Metode : quasi eksperiment design with control group, purposive sampling, 30 subyek (15 kelompok intervensi, 15 kelompok kontrol). Intervensi, subyek dengan captopril ditambahkan seduhan kering bunga rosella. Kontrol subyek mendapatkan dengan captopril saja. Sistolik pre kelompok intervensi, pada kategori hipertensi grade I, II, III. Sistolik post masuk pada kategori normal, pre hipertensi, hipertensi grade I, II, III. Diastolik pre kelompok intervensi terbesar kategori pre hipertensi, post diastolik terbesar berada pada kategori normal. Kelompok kontrol sistolik pre terbesar pada hipertensi grade II, post berada pada hipertensi grade I. Diastolik kelompok kontrol pre terbesar pada hipertensi grade I, post terbesar hipertensi grade I. Dianalisis dengan uji T berpasangan, dan uji T tidak berpasangan, α ≤ 0,05. Hasil Uji T berpasangan tekanan darah pre-post sistolik p-value 0,000, diastolik p-value 0,004, didapatkan pengaruh bunga rosella terhadap penderita hipertensi dengan captopril, penurunan tekanan darah kelompok intervensi sistolik 19,333, diastolik 10,000 mmHg, kelompok kontrol sistolik 9,000 mmHg, diastolik 4,333 mmHg. Hasil Uji T tidak berpasangan di dapatkan perbedaan penurunan tekanan darah kelompok intervensi lebih besar dibadingkan kelompok kontrol, dengan p-value, sistolik 0,000, diastolik 0,025. Perbedaan penurunan sistolik sebesar 12,333 mmHg, diastolik 6,333 mmHg. Kesimpulan didapatkan pengaruh pemberian bunga rosella terhadap Perubahan tekanan darah penderita hipertensi dengan terapi captopri

    X-ray irradiated cultures of mouse cortical neural stem/progenitor cells recover cell viability and proliferation with dose-dependent kinetics

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    Exposure of the developing or adult brain to ionizing radiation (IR) can cause cognitive impairment and/ or brain cancer, by targeting neural stem/progenitor cells (NSPCs). IR effects on NSPCs include transient cell cycle arrest, permanent cell cycle exit/differentiation, or cell death, depending on the experimental conditions. In vivo studies suggest that brain age influences NSPC response to IR, but whether this is due to intrinsic NSPC changes or to niche environment modifications remains unclear. Here, we describe the dose-dependent, time-dependent effects of X-ray IR in NSPC cultures derived from the mouse foetal cerebral cortex. We show that, although cortical NSPCs are resistant to low/moderate IR doses, high level IR exposure causes cell death, accumulation of DNA double-strand breaks, activation of p53- related molecular pathways and cell cycle alterations. Irradiated NSPC cultures transiently upregulate differentiation markers, but recover control levels of proliferation, viability and gene expression in the second week post-irradiation. These results are consistent with previously described in vivo effects of IR in the developing mouse cortex, and distinct from those observed in adult NSPC niches or in vitro adult NSPC cultures, suggesting that intrinsic differences in NSPCs of different origins might determine, at least in part, their response to IR

    Depletion of ATP-Citrate Lyase (ATPCL) Affects Chromosome Integrity Without Altering Histone Acetylation in Drosophila Mitotic Cells

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    The Citrate Lyase (ACL) is the main cytosolic enzyme that converts the citrate exported from mitochondria by the SLC25A1 carrier in Acetyl Coenzyme A (acetyl-CoA) and oxaloacetate. Acetyl-CoA is a high-energy intermediate common to a large number of metabolic processes including protein acetylation reactions. This renders ACL a key regulator of histone acetylation levels and gene expression in diverse organisms including humans. We have found that depletion of ATPCL, the Drosophila ortholog of human ACL, reduced levels of Acetyl CoA but, unlike its human counterpart, does not affect global histone acetylation and gene expression. Nevertheless, reduced ATPCL levels caused evident, although moderate, mitotic chromosome breakage suggesting that this enzyme plays a partial role in chromosome stability. These defects did not increase upon X-ray irradiation, indicating that they are not dependent on an impairment of DNA repair. Interestingly, depletion of ATPCL drastically increased the frequency of chromosome breaks (CBs) associated to mutations in scheggia, which encodes the ortholog of the mitochondrial citrate carrier SLC25A1 that is also required for chromosome integrity and histone acetylation. Our results indicate that ATPCL has a dispensable role in histone acetylation and prevents massive chromosome fragmentation when citrate efflux is altered
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