Investigation of PAL-1 requirement in C. elegans physiology using the auxin-inducible degradation system.

The C. elegans PAL-1 protein encodes a caudal-like transcription factor that is required for posterior development and was recently implicated in stress response. We generated a transgenic strain of C. elegans with AID*::3xFLAG::wrmScarlet cassette knocked in at the C-terminal end of the pal-1 locus to enable an auxin-inducible degradation of PAL-1 . We found that auxin-induced degradation of PAL-1 starting from the L1 larval stage does not affect body length development but renders the animal sterile and shortens lifespan. This pal-1 ::AID*::3xFLAG::wrmScarlet strain will be a valuable resource for studying the requirement of PAL-1 in a temporal and tissue-specific manner.

CCR4-NOT subunit CCF-1/CNOT7 promotes transcriptional activation to multiple stress responses in Caenorhabditis elegans.

CCR4-NOT is a versatile eukaryotic protein complex that controls multiple steps in gene expression regulation from synthesis to decay. In yeast, CCR4-NOT has been implicated in stress response regulation, though this function in other organisms remains unclear. In a genome-wide RNAi screen, we identified a subunit of the CCR4-NOT complex, ccf-1, as a requirement for the C. elegans transcriptional response to cadmium and acrylamide stress. Using whole-transcriptome RNA sequencing, we show that the knockdown of ccf-1 attenuates the activation of a broad range of stress-protective genes in response to cadmium and acrylamide, including those encoding heat shock proteins and xenobiotic detoxification. Consistently, survival assays show that the knockdown of ccf-1 decreases C. elegans stress resistance and normal lifespan. A yeast 2-hybrid screen using a CCF-1 bait identified the homeobox transcription factor PAL-1 as a physical interactor. Knockdown of pal-1 inhibits the activation of ccf-1 dependent stress genes and reduces C. elegans stress resistance. Gene expression analysis reveals that knockdown of ccf-1 and pal-1 attenuates the activation of elt-2 and elt-3 under stress that encode master transcriptional co-regulators of stress response in the C. elegans, and that overexpression of ELT-2 can suppress ccf-1's requirement for gene transcription in a stress-dependent manner. Our findings reveal a new role for CCR4-NOT in the environmental stress response and define its role in stress resistance and longevity in C. elegans.

Naringenin: A potential flavonoid phytochemical for cancer therapy.

Naringenin is an important phytochemical which belongs to the flavanone group of polyphenols, and is found mainly in citrus fruits like grapefruits and others such as tomatoes and cherries plus medicinal plants derived food. Available evidence demonstrates that naringenin, as herbal medicine, has important pharmacological properties, including anti-inflammatory, antioxidant, neuroprotective, hepatoprotective, and anti-cancer activities. Collected data from in vitro and in vivo studies show the inactivation of carcinogens after treatment with pure naringenin, naringenin-loaded nanoparticles, and also naringenin in combination with anti-cancer agents in various malignancies, such as colon cancer, lung neoplasms, breast cancer, leukemia and lymphoma, pancreatic cancer, prostate tumors, oral squamous cell carcinoma, liver cancer, brain tumors, skin cancer, cervical and ovarian cancer, bladder neoplasms, gastric cancer, and osteosarcoma. Naringenin inhibits cancer progression through multiple mechanisms, like apoptosis induction, cell cycle arrest, angiogenesis hindrance, and modification of various signaling pathways including Wnt/ß-catenin, PI3K/Akt, NF-ĸB, and TGF-ß pathways. In this review, we demonstrate that naringenin is a natural product with potential for the treatment of different types of cancer, whether it is used alone, in combination with other agents, or in the form of the naringenin-loaded nanocarrier, after proper technological encapsulation.

Translational suppression via IFG-1/eIF4G inhibits stress-induced RNA alternative splicing in Caenorhabditis elegans.

Splicing of precursor mRNA is an essential process for dividing cells, and splicing defects have been linked to aging and various chronic diseases. Environmental stress has recently been shown to modify alternative splicing, and molecular mechanisms that influence stress-induced alternative splicing remain unclear. Using an in vivo RNA splicing reporter, we performed a genome-wide RNAi screen in Caenorhabditis elegans and found that protein translation suppression via silencing of the conserved eukaryotic initiation factor 4G (IFG-1/eIF4G) inhibits cadmium-induced alternative splicing. Transcriptome analysis of an ifg-1-deficient mutant revealed an overall decrease in intronic and intergenic reads and prevented cadmium-induced alternative splicing compared to the wild type. We found that the ifg-1 mutant up-regulates >80 RNA splicing regulatory genes controlled by the TGF-ß transcription factor SMA-2. The extended lifespan of the ifg-1 mutant is partially reduced upon sma-2 depletion and completely nullified when core spliceosome genes including snr-1, snr-2, and uaf-2 are knocked down. Depletion of snr-1 and snr-2 also diminished the enhanced cadmium resistance of the ifg-1 mutant. Together, these data describe a molecular mechanism through which translation suppression inhibits stress-induced alternative splicing and demonstrate an essential role for RNA splicing in promoting longevity and stress resistance in a translation-compromised mutant.

Molecular characterization of ethyl carbamate toxicity in Caenorhabditis elegans.

Ethyl carbamate is a common contaminant prevalent in fermented food with probable carcinogenic effects in animals. To date, other toxicological properties of ethyl carbamate are not well characterized. Using the genetic model Caenorhabditis elegans, we found that chronic exposure to ethyl carbamate during larval development impedes growth while exposure during adulthood inhibits reproduction, shortens lifespan, and promotes degeneration to dopaminergic neurons. Through whole-transcriptome RNA-sequencing, we found that ethyl carbamate invokes a widespread transcriptomic response inducing the differential expression of > 4,000 genes by at least 2-fold. Functional analysis of RNA-sequencing data revealed that up-regulated genes enrich to various neuron regulatory processes and xenobiotic defense. Gene expression analysis confirms that various genes encoding antioxidant enzymes and those functioning within phase I and II detoxification responses along with ABC transporters are highly up-regulated after ethyl carbamate exposure, suggesting the onset of oxidative stress. Overall, these findings report new toxicological properties of chronic ethyl carbamate exposure and provide new insights on its effects on transcriptome regulation in the C. elegans model.

Degradation of phosalone by silver ion catalytic hydrolysis.

Pesticides application is expanding globally as the worldwide population increases demanding a secure and safe food supply. Organophosphorus (OP) pesticides, as a group, are widely used because they are rapidly degraded in the environment and because they have excellent efficacy and an acceptable price point. However, the chemical fate of organophosphorus pesticides is influenced by several factors, including their chemistry in aquatic environments. Among many degradation choices, hydrolysis by metal ions appears to be a good approach. Dissolved metal ions have been shown to promote the hydrolysis of organophosphorus pesticides. Using silver ion, we showed the effectiveness under in vitro and in vivo conditions for this metal ion to decontaminate water polluted by the organophosphorus phosalone. Phosalone was completely degraded in the presence of silver ions in a mole ratio of 7:1 in 20 min. Rainbow trout were divided into experimental groups to investigate the most effective ratio of silver/phosalone for pesticide degradation. Silver ion (2%) at a concentration of 0.75 and 0.1 mL removed phosalone (2%) at concentrations of 0.4 and 0.5 mL. All the rainbow trout survived in these two groups. This experiment suggested that silver ions can be beneficial at ratios in the range of 1:4 to 1:6 by hydrolyzing phosalone by attacking the electron-deficient phosphorus atom in the pesticide.

Effects of COX inhibitors on responsiveness of the tracheal tract to acetylcholine and histamine and their relationship with LTC4 and PGE2 levels of bronchoalveolar lavage fluid in allergic Guinea pigs.

Introduction: Nonsteroidal anti-inflammatory drugs (NSAIDs) intervene in the COX (cyclooxygenase) pathways which generate two important inflammation mediators, prostaglandins (PGs) and leukotriene (LTs). Contradictory claims regarding the effect of NSAIDs in asthmatic patients continues to be an issue. The present study investigated the effects of COX inhibitors on the responsiveness of the tracheal tract and on the levels of LTC4 and PGE2 in cells of the bronchoalveolar lavage fluid in an allergic guinea pig model.Materials and Methods: Adult male Dunkin-Hartley guinea pigs (250 - 300 g) were divided into seven groups of six animals each. Four COX inhibitors, aspirin (200 mg/kg and 20 mg/kg), indomethacin (10 mg/kg), ketoprofen (10 mg/kg), and celecoxib (25 mg/kg), were given orally on day 17 to allergy induced guinea pigs at 0, 12, and 24 h before ovalbumin challenge on day 18. PGF2 and LT4 were measured in the bronchoalveolar lavage fluid as well as inflammatory cell count and total protein. Tracheal responsiveness to acetylcholine (Ach) and histamine (His) also was evaluated.Results: An augment in the response of the trachea to Ach and His, as well as overt allergenic signs including short breath, wheezing and sneezing, was observed. The most significant increase in tracheal hyper-responsiveness was observed in the ketoprofen-treated group with similar but less pronounced changes observed in the indomethacin-treated group. Although some variables increased with the aspirin and celecoxib treatments, overall the tracheal sensitivity was reduced. Inflammatory cells including eosinophils and neutrophils corresponded to the changes observed for each treatment group.Conclusion: Ketoprofen and indomethacin increased the tracheal sensibility to Ach and His; therefore, their administration is not recommended in patients susceptible to allergy.

Evaluation of the acute and sub-acute toxicity of the black caraway seed essential oil in Wistar rats.

The aim of the present study was to evaluate the acute toxicity as lethal dose 50% (LD50) and sub-acute toxicity of the black caraway Bunium persicum (Bioss) seed essential oil in male Wistar rats. The compounds of B. persicum were identified by GC/MS and amount of each compound was evaluated. 21 different compounds were determined in the essential oil and the main components were: carvone, p-cymene, gamma-terpinene, p-cymene-8-ol, limonene, isoterpinolene, and 2-beta pinene. For acute toxicity evaluation, the animals were randomly divided into nine group (n = 6) and received 500, 1000, 1500, 2000, 2500, 3000, 3500 and 4000 mg/kg seed essential oil, respectively and the LD50 value for black caraway seed essential oil was obtained above 4000 mg/kg body weight. According to data, treatment with the black caraway seed essential oil sub-acute toxicity study attenuated histopathological changes in lung, liver, kidney, testes and spleen tissues and the results of this study show that the black caraway essential oil can not affect the immune and blood system, important enzymes and vital organs of the body..