Decrease In Protein Synthesis Research Articles

Decreased synthesis of ribosomal proteins in tauopathy revealed by non‐canonical amino acid labelling

Tau is a scaffolding protein that serves multiple cellular functions that are perturbed in neurodegenerative diseases, including Alzheimer's disease (AD) and frontotemporal dementia (FTD). We have recently shown that amyloid‐β, the second hallmark of AD, induces de novo protein synthesis of tau. Importantly, this activation was found to be tau‐dependent, raising the question of whether FTD‐tau by itself affects protein synthesis. We therefore applied non‐canonical amino acid labelling to visualise and identify newly synthesised proteins in the K369I tau transgenic K3 mouse model of FTD. This revealed massively decreased protein synthesis in neurons containing pathologically phosphorylated tau, a finding confirmed in P301L mutant tau transgenic rTg4510 mice. Using quantitative SWATH‐MS proteomics, we identified changes in 247 proteins of the de novo proteome of K3 mice. These included decreased synthesis of the ribosomal proteins RPL23, RPLP0, RPL19 and RPS16, a finding that was validated in both K3 and rTg4510 mice. Together, our findings present a potential pathomechanism by which pathological tau interferes with cellular functions through the dysregulation of ribosomal protein synthesis.

Thallium(I) treatment induces nucleolar stress to stop protein synthesis and cell growth

Thallium is considered as an emergent contaminant owing to its potential use in the superconductor alloys. The monovalent thallium, Tl(I), is highly toxic to the animals as it can affect numerous metabolic processes. Here we observed that Tl(I) decreased protein synthesis and phosphorylated eukaryotic initiation factor 2α. Although Tl(I) has been shown to interact with the sulfhydryl groups of proteins and cause the accumulation of reactive oxygen species, it did not activate endoplasmic reticulum stress. Notably, the level of 60S ribosomal subunit showed significant under-accumulation after the Tl(I) treatment. Given that Tl(I) shares similarities with potassium in terms of the ionic charge and atomic radius, we proposed that Tl(I) occupies certain K+-binding sites and inactivates the ribosomal function. However, we observed neither activation of ribophagy nor acceleration of the proteasomal degradation of 60S subunits. On the contrary, the ribosome synthesis pathway was severely blocked, i.e., the impairment of rRNA processing, deformed nucleoli, and accumulation of 60S subunits in the nucleus were observed. Although p53 remained inactivated, the decreased c-Myc and increased p21 levels indicated the activation of nucleolar stress. Therefore, we proposed that Tl(I) interfered the ribosome synthesis, thus resulting in cell growth inhibition and lethality.

Tylophorine reduces protein biosynthesis and rapidly decreases cyclin D1, inhibiting vascular smooth muscle cell proliferation in vitro and in organ culture

BackgroundTylophorine (TYL) is an alkaloid with antiproliferative action in cancer cells. Vascular smooth muscle cell (VSMC) proliferation and neointima formation contribute to restenosis after percutaneous coronary interventions. Hypothesis/PurposeOur goal was to examine the potential of TYL to inhibit VSMC proliferation and migration, and to dissect underlying signaling pathways. Study design and methodsTYL was administered to platelet-derived growth factor (PDGF-BB)-stimulated, serum-stimulated, quiescent and unsynchronized VSMC of rat and human origin. BrdU incorporation and resazurin conversion were used to assess cell proliferation. Cell cycle progression was analyzed by flow cytometry of propidium iodide-stained nuclei. Expression profiles of proteins and mRNAs were determined using western blot analysis and RT-qPCR. The Click-iT OPP Alexa Fluor 488 assay was used to monitor protein biosynthesis. ResultsTYL inhibited PDGF-BB-induced proliferation of rat aortic VSMCs by arresting cells in G1 phase of the cell cycle with an IC50 of 0.13 µmol/l. The lack of retinoblastoma protein phosphorylation and cyclin D1 downregulation corroborated a G1 arrest. Inhibition of proliferation and cyclin D1 downregulation were species- and stimulus-independent. TYL also decreased levels of p21 and p27 proteins, although at later time points than observed for cyclin D1. Co-treatment of VSMC with TYL and MG132 or cycloheximide (CHX) excluded proteasome activation by TYL as the mechanism of action. Comparable time-dependent downregulation of cyclin D1, p21 and p27 in TYL- or CHX-treated cells, together with decreased protein synthesis observed in the Click-iT assay, suggests that TYL is a protein synthesis inhibitor. Besides proliferation, TYL also suppressed migration of PDGF-activated VSMC. In a human saphenous vein organ culture model for graft disease, TYL potently inhibited intimal hyperplasia. ConclusionThis unique activity profile renders TYL an interesting lead for the treatment of vasculo-proliferative disorders, such as restenosis.

Sarcopenia: Ammonia metabolism and hepatic encephalopathy.

Sarcopenia (loss of muscle mass and/or strength) frequently complicates liver cirrhosis and adversely affects the quality of life; cirrhosis related liver decompensation and significantly decreases wait-list and post-liver transplantation survival. The main therapeutic strategies to improve or reverse sarcopenia include dietary interventions (supplemental calorie and protein intake), increased physical activity (supervised resistance and endurance exercises), hormonal therapy (testosterone), and ammonia lowering agents (L-ornithine L-aspartate, branch chain amino acids) as well as mechanistic approaches that target underlying molecular and metabolic abnormalities. Besides other factors, hyperammonemia has recently gained attention and increase sarcopenia by various mechanisms including increased expression of myostatin, increased phosphorylation of eukaryotic initiation factor 2a, cataplerosis of α ketoglutarate, mitochondrial dysfunction, increased reactive oxygen species that decrease protein synthesis and increased autophagy-mediated proteolysis. Sarcopenia contributes to frailty and increases the risk of minimal and overt hepatic encephalopathy.

Identification and Characterization of Allograft Inflammatory Factor 1‐Like (Aif1L) in Skeletal Muscle

Skeletal muscle wasting, or atrophy, results from decreased protein synthesis and an associated increase in protein degradation. This shift towards a decrease in protein content of the cell can result from various physiological conditions, including immobilization, denervation, and aging. Muscle RING Finger 1 (MuRF1), an E3 ubiquitin ligase, has been found to be upregulated during almost all conditions of muscle wasting and is believed to play an important role in targeting proteins for degradation. However, preliminary data described in this study provides new evidence that MuRF1's role in the skeletal muscle atrophy cascade is likely more complex and it appears that MuRF1 is necessary for full transcriptional activation of a small subset of neurogenic atrophy‐induced genes, including allograft inflammatory factor 1‐like (Aif1L). Aif1L has been identified as a novel skeletal muscle gene that is upregulated in wild‐type mice, while MuRF1‐null mice show blunted upregulation in response to denervation. Aif1L is predicated to contain an EF‐hand domain, which can act as a calcium ion binding domain. Furthermore, Aif1L has also recently been implicated in regulating actomyosin contractility and filopodial extensions and may play a similar role in muscle cells. To confirm that Aif1L in expressed in muscle cells, qPCR was used to assess the expression levels in cultured muscle cells, while the cDNA of Aif1L was cloned from the C2C12 mouse myoblast cell line and fused with a green fluorescence protein (GFP) tag. C2C12 cells were then transfected with the Aif1L‐GFP expression plasmid in order to localize the Aif1L protein in proliferating myoblast cells. C2C12 cells transiently overexpressing Aif1L fused to GFP showed punctate fluorescence localized to the perinuclear region of the cytoplasm. The results presented here in combination with additional research into the transcriptional regulation and function of Aif1L will help contribute new insight into the molecular genetic mechanisms of skeletal muscle atrophy and may provide a more complete understanding of how MuRF1 may regulate the neurogenic atrophy cascade during muscle wasting.Support or Funding InformationThe work was support by University of North Florida Transformational Learning Opportunity grants and a University of North Florida Foundation Board Grant to D.W.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Ubiquitin C-terminal hydrolase L1 (UCH-L1) loss causes neurodegeneration by altering protein turnover in the first postnatal weeks

Ubiquitin C-terminal hydrolase L1 (UCH-L1) is one of the most abundant and enigmatic enzymes of the CNS. Based on existing UCH-L1 knockout models, UCH-L1 is thought to be required for the maintenance of axonal integrity, but not for neuronal development despite its high expression in neurons. Several lines of evidence suggest a role for UCH-L1 in mUB homeostasis, although the specific in vivo substrate remains elusive. Since the precise mechanisms underlying UCH-L1-deficient neurodegeneration remain unclear, we generated a transgenic mouse model of UCH-L1 deficiency. By performing biochemical and behavioral analyses we can show that UCH-L1 deficiency causes an acceleration of sensorimotor reflex development in the first postnatal week followed by a degeneration of motor function starting at periadolescence in the setting of normal cerebral mUB levels. In the first postnatal weeks, neuronal protein synthesis and proteasomal protein degradation are enhanced, with endoplasmic reticulum stress, and energy depletion, leading to proteasomal impairment and an accumulation of nondegraded ubiquitinated protein. Increased protein turnover is associated with enhanced mTORC1 activity restricted to the postnatal period in UCH-L1-deficient brains. Inhibition of mTORC1 with rapamycin decreases protein synthesis and ubiquitin accumulation in UCH-L1-deficient neurons. Strikingly, rapamycin treatment in the first 8 postnatal days ameliorates the neurological phenotype of UCH-L1-deficient mice up to 16 weeks, suggesting that early control of protein homeostasis is imperative for long-term neuronal survival. In summary, we identified a critical presymptomatic period during which UCH-L1-dependent enhanced protein synthesis results in neuronal strain and progressive loss of neuronal function.

Effects of low-dose leucine supplementation on gastrocnemius muscle mitochondrial content and protein turnover in tumor-bearing mice.

Many forms of cancer are associated with loss of lean body mass, commonly attributed to decreased protein synthesis and stimulation of proteolytic pathways within the skeletal muscle. Leucine has been shown to improve protein synthesis, insulin signaling, and mitochondrial biogenesis, which are key signaling pathways influenced by tumor signaling. The purpose of this study was to examine the effects of leucine supplementation on mitochondrial biogenesis and protein turnover in tumor-bearing mice. Twenty male C57BL/6 mice were divided into 4 groups (n = 5): Chow, leucine (Leu), Lewis lung carcinoma (LLC) implant, and LLC+Leu. At 9-10 weeks of age, mice were inoculated and supplemented with 5% leucine (w/w) in the diet. C2C12 myotubes were treated with 2.5 mmol/L leucine and 25% LLC conditioned media to further elucidate the direct influence of the tumor and leucine on the muscle. Measures of protein synthesis, mitochondrial biogenesis, and inflammation in the gastrocnemius were assessed via Western blot analysis. Gastrocnemius mass was decreased in LLC+Leu relative to LLC (p = 0.040). Relative protein synthesis rate was decreased in LLC mice (p = 0.001). No change in protein synthesis was observed in myotubes. Phosphorylation of STAT3 was decreased in the Leu group relative to the control in both mice (p = 0.019) and myotubes (p = 0.02), but did not significantly attenuate the inflammatory effect of LLC implantation (p = 0.619). LLC decreased markers of mitochondrial content; however, PGC-1α was increased in LLC+Leu relative to LLC (p = 0.001). While leucine supplementation was unable to preserve protein synthesis or mitochondrial content associated with LLC implantation, it was able to increase mitochondrial biogenesis signaling. Novelty This study provides novel insights on the effect of leucine supplementation on mitochondrial biogenesis and protein turnover in tumor-bearing mice. Leucine increased signaling for mitochondrial biogenesis in the skeletal muscle. Leucine supplementation decreased inflammatory signaling in skeletal muscle.

Moderate exercise in mice improves cancer plus chemotherapy-induced muscle wasting and mitochondrial alterations.

Cancer cachexia is a multifactorial syndrome characterized by anorexia, body wasting, and muscle and adipose tissue loss, impairing patient's tolerance to anticancer treatments and survival. The aim of the present study was to compare the effects induced in mice by tumor growth alone (C26) or in combination with chemotherapy [C26 oxaliplatin and 5-fluorouracil (oxfu)] and to evaluate the potential of moderate exercise. Oxfu administration to C26 mice exacerbated muscle wasting and triggered autophagy or mitophagy, decreased protein synthesis, and induced mitochondrial alterations. Exercise in C26 oxfu mice counteracted the loss of muscle mass and strength, partially rescuing autophagy and mitochondrial function. Nevertheless, exercise worsened survival in C26 oxfu mice in late stages of cachexia. In summary, chemotherapy further impinges on cancer-induced alterations, worsening muscle wasting. An ideal multifactorial and early intervention to prevent cancer cachexia could take advantage of exercise, improving patient's energy metabolism, mobility, and quality of life.-Ballarò, R., Beltrà, M., De Lucia, S., Pin, F., Ranjbar, K., Hulmi, J. J., Costelli, P., Penna, F. Moderate exercise in mice improves cancer plus chemotherapy-induced muscle wasting and mitochondrial alterations.

Fasting in the ureotelic Lake Magadi tilapia, Alcolapia grahami, does not reduce its high metabolic demand, increasing its vulnerability to siltation events.

Lake Magadi, Kenya, is one of the most extreme aquatic environments on Earth (pH~10, anoxic to hyperoxic, high temperatures). Recently, increased water demand and siltation have threatened the viable hot springs near the margins of the lake where Alcolapia grahami, the only fish surviving in the lake, live. These Lake Magadi tilapia largely depend on nitrogen-rich cyanobacteria for food and are 100% ureotelic. Their exceptionally high aerobic metabolic rate, together with their emaciated appearance, suggests that they are energy-limited. Therefore, we hypothesized that during food deprivation, Magadi tilapia would economize their energy expenditure and reduce metabolic rate, aerobic performance and urea-N excretion. Surprisingly, during a 5-day fasting period, routine metabolic rates increased and swimming performance (critical swimming speed) was not affected. Urea-N excretion remained stable despite the lack of their N-rich food source. Their nitrogen use switched to endogenous sources as liver and muscle protein levels decreased after a 5-day fast, indicating proteolysis. Additionally, fish relied on carbohydrates with lowered muscle glycogen levels, but there were no signs indicating use of lipid stores. Gene expression of gill and gut urea transporters were transiently reduced as were gill rhesus glycoprotein Rhbg and Rhcg-2. The reduction in gill glutamine synthetase expression concomitant with the reduction in Rh glycoprotein gene expression indicates reduced nitrogen/ammonia metabolism, most likely decreased protein synthesis. Additionally, fish showed reduced plasma total CO2, osmolality and Na+ (but not Cl−) levels, possibly related to reduced drinking rates and metabolic acidosis. Our work shows that Lake Magadi tilapia have the capacity to survive short periods of starvation which could occur when siltation linked to flash floods covers their main food source, but their seemingly hardwired high metabolic rates would compromise long-term survival.

Inhibition of Proteasomes by Bortezomib Decreases MuRF-1 and MAFbx mRNA Expression in Rat Soleus during Hindlimb Unloading

Skeletal muscle atrophy caused by unloading is accompanied by increased proteolysis and decreased protein synthesis. It is established that in conditions of muscle unloading, concentration of free amino acids is increased. We hypothesized that proteasome inhibition may decrease amino acid accumulation in skeletal muscle and prevent the atrophy. To test this hypothesis, we treated rats with bortezomib (a proteasome inhibitor) during 7-day hindlimb suspension. Content of key signaling proteins of various signaling pathways was measured by Western-blotting; mRNA level of E3 ligases by RT-PCR, rate of protein synthesis by SUnSET technique. Soleus muscle weight and intensity of the protein synthesis in the groups of “hindlimb suspension” (HS) and “HS + bortezomib” (HSB) were equally reduced as compared to control. Levels of MuRF-1 and MAFbx mRNAs, content of MuRF-1 and calpain-1 proteins, and level of the protein ubiquitination were increased only in the HS group and remained unchanged in the HSB group as compared to the control group. We conclude that inhibition of proteasomes during m. soleus unloading prevents increase in activity of some components of catabolic signaling pathways. However, this is not sufficient to reduce rate of the atrophic processes in skeletal muscle.

Sleep and Intensive Care Unit-Acquired Weakness in Critically Ill Older Adults.

Older adults in the intensive care unit (ICU) often experience sleep disturbances, which may stem from life-threatening illness, the ICU environment, medications/sedation, or psychological stress. Two complementary endocrinological responses occur as a result of compromised sleep and consequently could exacerbate ICU-acquired weakness: a decrease in anabolic hormones leading to decreased protein synthesis and an increase in catabolic hormones leading to increased protein degradation. Age-associated decreases in anabolic hormones, such as insulin-like growth factor 1, testosterone, and growth hormone, may inhibit protein synthesis. Likewise, age-associated increases in insulin resistance, glucocorticoids, and myostatin can stimulate muscle atrophy and further reduce protein synthesis. Thus, perhaps, sleep promotion in the ICU may attenuate muscle atrophy among critically ill older adults who are at risk for ICU-acquired weakness and subsequent functional decline. The aim of this study was to discuss the hypothesized theoretical underpinnings of the relationship between sleep disturbances and ICU-acquired weakness among critically ill older adults. A search of research literature published from 1970 to 2018 and indexed in MEDLINE, Embase, CINAHL, and Ovid was undertaken, and relevant sources were selected to build an informed discussion. Nurses must be mindful of secondary sleep disturbances that occur throughout the acute phase of critical illness and their probable links to ICU-acquired weakness. Targeted interventions to promote functional outcomes in elderly patients should consider this relationship. Improved sleep may have the potential to decrease the severity of muscle atrophy and ICU-acquired weakness. Future research must explore this hypothesis and the underlying mechanisms of the association between sleep disturbances and ICU-acquired weakness in critically ill older adults.

Novel Factors of Viral Origin Inhibit TOR Pathway Gene Expression.

Polydnaviruses (PDVs) are obligate symbionts of endoparasitoid wasps, which exclusively attack the larval stages of their lepidopteran hosts. The Polydnavirus is injected by the parasitoid female during oviposition to selectively infect host tissues by the expression of viral genes without undergoing replication. Toxoneuron nigriceps bracovirus (TnBV) is associated with Toxoneuron nigriceps (Hymenoptera: Braconidae) wasp, an endoparasitoid of the tobacco budworm larval stages, Heliothis virescens (Lepidoptera: Noctuidae). Previous studies showed that TnBV is responsible for alterations in host physiology. The arrest of ecdysteroidogenesis is the main alteration which occurs in last (fifth) instar larvae and, as a consequence, prevents pupation. TnBV induces the functional inactivation of H. virescens prothoracic glands (PGs), resulting in decreased protein synthesis and phosphorylation. Previous work showed the involvement of the PI3K/Akt/TOR pathway in H. virescens PG ecdysteroidogenesis. Here, we demonstrate that this cellular signaling is one of the targets of TnBV infection. Western blot analysis and enzyme immunoassay (EIA) showed that parasitism inhibits ecdysteroidogenesis and the phosphorylation of the two targets of TOR (4E-BP and S6K), despite the stimulation of PTTH contained in the brain extract. Using a transcriptomic approach, we identified viral genes selectively expressed in last instar H. virescens PGs, 48 h after parasitization, and evaluated expression levels of PI3K/Akt/TOR pathway genes in these tissues. The relative expression of selected genes belonging to the TOR pathway (tor, 4e-bp, and s6k) in PGs of parasitized larvae was further confirmed by qRT-PCR. The down-regulation of these genes in PGs of parasitized larvae supports the hypothesis of TnBV involvement in blocking ecdysteroidogenesis, through alterations of the PI3K/Akt/TOR pathway at the transcriptional level.

Phenotypic and molecular features underlying neurodegeneration of motor neurons derived from spinal and bulbar muscular atrophy patients

Spinal and bulbar muscular atrophy (SBMA) is a neurodegenerative disease caused by the expansion of polyglutamine region in the androgen receptor. To gain insights into mechanisms of SBMA, four wild-type and five SBMA iPSC lines were differentiated to spinal motor neurons (sMNs) with high efficiency. SBMA sMNs showed neurite defects, reduced sMN survival and decreased protein synthesis levels. Microarray analysis revealed a dysregulation in various neuronal-related signalling pathways in SBMA sMNs. Strikingly, FAM135B a novel gene of unknown function, was found drastically downregulated in SBMA sMNs. Knockdown of FAM135B in wild-type sMNs reduced their survival and contributed to neurite defects, similar to SBMA sMNs, suggesting a functional role of FAM135B in SBMA. The degenerative phenotypes and dysregulated genes revealed could be potential therapeutic targets for SBMA.

Postnatal changes in the development of rat submandibular glands in offspring of diabetic mothers: Biochemical, histological and ultrastructural study.

Development and maturation of submandibular salivary glands are influenced by intrauterine diabetic environment. Several studies investigated the effects of diabetes on the salivary glands. However, the effects of maternal diabetes on the submandibular glands of the offspring was not properly examined. Therefore, the present study was designed to describe the changes in the development of the submandibular glands of the offspring of diabetic mothers. The submandibular glands of the offspring of Streptozotocin (STZ)-induced diabetic female rats were examined at two and four weeks after birth. Detection of mRNA demonstrated that maternal diabetes affects the level of different indicators. The reduction of expression of epidermal growth factor (EGF); a protein mitogen, cytokeratin 5 (CK5); an epithelial cell progenitor, CK7 and aquaporin 5 (AQP5); differentiation markers and B cell lymphoma 2 (Bcl2); an antiapoptotic marker were found. Increase in Bcl2-associated X protein (Bax); an apoptotic marker was detected. These changes indicate their effects on saliva secretion, glands tumorigenesis, growth of normal oral flora and oral microbes, with decreased protein synthesis and production of xerostomia and dental caries. Loss of normal glandular architecture, significant increase in fibrosis, by the detection of collagen fibers, and stagnation of secretory granules were found with atrophic changes in the acinar cells. Marked defect of polysaccharides in the acinar cells, denoting functional changes, was manifested by significant reduction of the intensity of periodic acid-Schiff (PAS) reaction. The positive immunoreactivity of caspase-3, denoting cellular apoptosis, and minimal reaction of alpha-smooth muscle actin (α SMA) and proliferating cell nuclear antigen (PCNA) were evident in the offspring of diabetic mothers. We conclude that maternal diabetes produces degenerative effects in the structure and function of the submandibular salivary glands of the offspring, reflecting possible influences on their secretory activity affecting oral and digestive health.

Metformin: Focus on Melanoma.

Metformin is the most common biguanide used in the treatment of diabetes, with 120 million treated patients worldwide. Metformin decreases hyperglycemia without inducing hypoglycemia in diabetic patients and is very well tolerated. The principal effects of metformin are to decrease hepatic gluconeogenesis and increase glucose absorption by skeletal muscles. These effects are primarily due to metformin's action on mitochondria, which requires the activation of metabolic checkpoint AMP-activated protein kinase (AMPK). AMPK is implicated in several pathways, and following metformin activation, it decreases protein synthesis and cell proliferation. Many studies have examined the role of metformin in the regulation of cancer cells, particularly its effects on cancer cell proliferation and cell death. Encouraging results have been obtained in different types of cancers, including prostate, breast, lung, and skin cancers (melanoma). Furthermore, many retrospective epidemiological studies in diabetes patients have shown that metformin treatment decreased the risk of cancers compared with other antidiabetic treatments. In this review, we will discuss the effects of metformin on melanoma cells. Together, our novel data demonstrate the importance of developing metformin and new biguanide-derived compounds as potential treatments against a number of different cancers, particularly melanoma.

Nutrient Deprivation Elicits a Transcriptional and Translational Inflammatory Response Coupled to Decreased Protein Synthesis

SUMMARYNutrient deprivation inhibits mRNA translation through mTOR and eIF2α signaling, but it is unclear how the translational program is controlled to reflect the degree of a metabolic stress. In a model of breast cellular transformation, various forms of nutrient deprivation differentially affect the rate of protein synthesis and its recovery over time. Genome-wide translational profiling of glutamine-deprived cells reveals a rapid upregulation of mRNAs containing uORFs and downregulation of ribosomal protein mRNAs, which are followed by selective translation of cytokine and inflammatory mRNAs. Transcription and translation of inflammatory and cytokine genes are stimulated in response to diverse metabolic stresses and depend on eIF2α phosphorylation, with the extent of stimulation correlating with the decrease in global protein synthesis. In accord with the inflammatory stimulus, glutamine deprivation stimulates the migration of transformed cells. Thus, pro-inflammatory gene expression is coupled to metabolic stress, and this can affect cancer cell behavior upon nutrient limitation.

Profil Protein Isolat Bakteri Resisten Merkuri Dari Pertambangan Emas Rakyat Di Desa Pongkor, Bogor-Jawa Barat, Indonesia

Mercury pollution due to gold mining at Pongkor Village can threaten the life of organisms because mercury is toxic. Bioremediation can be considered to reduce mercury concentration in the water. The mercury-resistant bacteria can be isolated from the area and may be developed as mercury bioremediation agents. This study aims to isolate mercury-resistant bacteria, test their resistance to mercury, and conduct protein profile studies after mercury induction. The mercury-resistant bacteria were isolated from soil samples in the Pongkor Village gold mining area and the isolate resistance to HgCl2 was measured based on the Minimum Inhibitory Concentration (MIC) value. The protein profile was analyzed using SDS PAGE gel electrophoresis. The results showed that two of the most resistant bacterial isolates to mercury were HgP1 and HgP2 with MIC value was 575 ppm. The protein profile showed that mercury induced decreased protein synthesis under normal conditions and increased synthesis of one protein suspected to play a role in the mechanism of bacterial resistance to mercury.

The helicase Ded1p controls use of near-cognate translation initiation codons in 5' UTRs.

The conserved and essential DEAD-box RNA helicase Ded1p from yeast and its mammalian ortholog DDX3 are critical for translation initiation1. Mutations in DDX3 are linked to tumorigenesis2–4 and intellectual disability5, and the enzyme is targeted by diverse viruses6. How Ded1p and its orthologs engage RNAs in translation initiation has been a longstanding, unresolved question. Here we integrate transcriptome-wide analyses of RNA translation, structure, and Ded1p-RNA binding and show that the impact of Ded1p on translation initiation is connected to near-cognate initiation codons in 5′UTRs. Ded1p associates with the scanning translation pre-initiation complex at the mRNA entry channel. Repression of Ded1p activity leads to accumulation of RNA structure in 5′UTRs, translation initiation from near-cognate start codons immediately upstream of these structures and decreased protein synthesis from the corresponding main ORFs. The data reveal a program for translation regulation that links Ded1p, activation of near-cognate start codons and mRNA structure. We show that this program plays a role in meiosis where a marked decrease in Ded1p levels is accompanied by activation of alternative translation initiation sites seen with repressed Ded1p activity. Our observations indicate that Ded1p impacts translation initiation by controlling the use of near-cognate initiation codons that are proximal to mRNA structure in 5′UTRs.

L-Carnitine and Resveratrol Action on Oxidative Response and Differentiation in H9c2 Rat Cardiomyocytes

Diabetic heart disease (DHD) results in structural and functional deterioration due to progressive loss of cardiomyocytes and cardiac stem cells, leading to a premature aging of the diabetic heart. The causes of DHD development are not completely clarified, but it is evident that higher oxidative stress of diabetes induces cardiac structural alterations. Recently, the use of stem cells or cardiac progenitors have inspired the most promising therapeutic strategies but these approaches are limited in diabetic patients. Herein we investigate L-Carnitine (LC) and Resveratrol (RSV) actions on oxidative stress and differentiation process in H9c2 rat cardiomyocytes. H9c2, during proliferation or differentiation condition, were treated with LC (0.5 or 5mM) or RSV (0.1 or 25μM). LC significantly enhanced anti-oxidative response by increasing (48 and 72h) mitochondrial SOD2 protein expression and STAT3 activation. LC did not induce p21 translocation at the nuclear level, demonstrating not to have an inhibitory effect on the cell cycle. LC decreased protein synthesis of CaMKII, whose activation is associated with hypertrophic process. In addition, the protective LC effect on H9c2 cardiomyocytes in stress condition was evaluated treating cells with LC 48h before exposure to H2O2: LC significantly reduced intracellular ROS concentration in a dose-dependent manner. RSV 0.1μM while increasing CaMKII content, did not show any effect on the proliferative potential of H9c2. RSV 25μM induced a significant proliferation decrease in favor of H9c2 differentiation, as shown by ERKs pathway activation and α-actinin protein synthesis promotion. RSV 25μM significantly reduced ROS generation induced by rotenone in neo cardiomyotubes (72h). The ability to improve the microenvironment damaged by oxidative stress and to stimulate cardiac progenitor differentiation could recognize LC/RSV as valid adjuvant therapies to preserve cardiomyocytes survival and ameliorate heart regeneration. Disclosure I. Terruzzi: None. P. Senesi: None. A. Montesano: None. F. Vacante: None. L. Luzi: Speaker's Bureau; Self; A. Menarini Diagnostics, AstraZeneca, Eli Lilly and Company. Research Support; Self; Gelesis. Consultant; Self; McKinsey & Company. Speaker's Bureau; Self; Menarini Group, Merck Sharp & Dohme Corp.. Research Support; Self; Novartis AG. Speaker's Bureau; Self; Novo Nordisk A/S. Research Support; Self; Sunstar Foundation. Speaker's Bureau; Self; Smith & Nephew.

Inflammatory and oxidative mechanisms potentiate bifenthrin-induced neurological alterations and anxiety-like behavior in adult rats

Bifenthrin (BF) is a synthetic pyrethroid pesticide widely used in several countries to manage insect pests on diverse agricultural crops. Growing evidence indicates that BF exposure is associated with an increased risk of developing neurodegenerative disorders. However, the mechanisms by which BF induces neurological and anxiety alterations in the frontal cortex and striatum are not well known. The present in vivo study was carried out to determine whether reactive oxygen species (ROS)-mediated oxidative stress (OS) and neuroinflammation are involved in such alterations. Thirty-six Wistar rats were thus randomly divided into three groups and were orally administered with BF (0.6 and 2.1 mg/kg body weight, respectively) or the vehicle (corn oil), on a daily basis for 60 days. Results revealed that BF exposure in rats enhanced anxiety-like behavior after 60 days of treatment, as assessed with the elevated plus-maze test by decreases in the percentage of time spent in open arms and frequency of entries into these arms. BF-treated rats also exhibited increased oxidation of lipids and carbonylated proteins in the frontal cortex and striatum, and decreased glutathione levels and antioxidant enzyme activities including superoxide dismutase, catalase and glutathione peroxidase. Treatment with BF also increased protein synthesis and mRNA expression of the inflammatory mediators cyclooxygenase-2 (COX-2), microsomal prostaglandin synthase-1 (mPGES-1) and nuclear factor-kappaBp65 (NF-kBp65), as well as the production of tumor necrosis factor-α (TNF-α) and ROS. Moreover, BF exposure significantly decreased protein synthesis and mRNA expression of nuclear factor erythroid-2 (Nrf2) and acetylcholinesterase (AChE), as well as gene expression of muscarinic–cholinergic receptors (mAchR) and choline acetyltransferase (ChAT) in the frontal cortex and striatum. These data suggest that BF induced neurological alterations in the frontal cortex and striatum of rats, and that this may be associated with neuroinflammation and oxidative stress via the activation of Nrf2/NF-kBp65 pathways, which might promote anxiety-like behavior.