Transcriptome analysis reveals molecular anthelmintic effects of procyanidins in C. elegans

An Inventory of Anthelmintic Plants across the Globe

A wide range of novelties and significant developments in the field of veterinary science to treat helminth parasites by using natural plant products have been assessed in recent years. To the best of our knowledge, to date, there has not been such a comprehensive review of 19 years of articles on the anthelmintic potential of plants against various types of helminths in different parts of the world. Therefore, the present study reviews the available information on a large number of medicinal plants and their pharmacological effects, which may facilitate the development of an effective management strategy against helminth parasites. An electronic search in four major databases (PubMed, Scopus, Web of Science, and Google Scholar) was performed for articles published between January 2003 and April 2022. Information about plant species, local name, family, distribution, plant tissue used, and target parasite species was tabulated. All relevant studies meeting the inclusion criteria were assessed, and 118 research articles were included. In total, 259 plant species were reviewed as a potential source of anthelmintic drugs. These plants can be used as a source of natural drugs to treat helminth infections in animals, and their use would potentially reduce economic losses and improve livestock production.

Condensed tannins act as anthelmintics by increasing the rigidity of the nematode cuticle

Tannins and tanniferous plant extracts have been discussed as sustainable means for helminth control in the past two decades in response to a dramatic increase of resistances towards standard anthelmintics. While their bioactivities have been broadly investigated in vitro and in vivo, less is known about their mode of action in nematodes, apart from their protein binding properties. In the current study we therefore investigated the impact of a phytochemically well characterized plant extract from Combretum mucronatum, known to contain procyanidins as the active compounds, on the model organism Caenorhabditis elegans. By different microscopic techniques, the cuticle was identified as the main binding site for tannins, whereas underlying tissues did not seem to be affected. In addition to disruptions of the cuticle structure, molting defects occurred at all larval stages. Finally, an increased rigidity of the nematodes' cuticle due to binding of tannins was confirmed by force spectroscopic measurements. This could be a key finding to explain several anthelmintic activities reported for tannins, especially impairment of molting or exsheathment as well as locomotion.

Using Caenorhabditis elegans to produce functional secretory proteins of parasitic nematodes

The expression of antigens in their immunologically-active form remains a challenge, both in the analysis of regulatory pathways exploited by parasitic nematodes or in the development of vaccines. Despite the success of native proteins to induce protective immunity, recombinant proteins expressed in bacteria, yeast or insect cells offer only limited protective capacities, presumably due to incorrect folding or missing complex posttranslational modifications. The present study investigates the feasibility of using the free-living nematode Caenorhabditis elegans as an alternative expression system for proteins found in the secretome of parasitic nematodes. Exemplified by the expression of the extracellular superoxide dismutase from Haemonchus contortus (HcSODe) and the extracellular and glycosylated glutathione S-transferase from the filarial parasite Onchocerca volvulus (OvGST1), we continue our efforts to improve production and purification of recombinant proteins expressed in C. elegans. We demonstrate that sufficient quantities of functional proteins can be expressed in C. elegans for subsequent immunological and biochemical studies.

Genome-Wide Expression Profiling of mRNAs, lncRNAs and circRNAs in Skeletal Muscle of Two Different Pig Breeds

Simple Summary

Variation exists in muscle-related traits, such as muscle growth and meat quality, between obese and lean pigs. In this study, the transcriptome profiles of skeletal muscle between Beijing Blackand Yorkshire pigs were characterized to explore the molecular mechanism underlying skeletal muscle-relatedtraits. Gene Ontology (GO) and KEGG pathway enrichment analyses showed that differentially expressed mRNAs, lncRNAs, and circRNAs involved in skeletal muscle development and fatty acid metabolism played a key role in the determination of muscle-related traits between different pig breeds. These results provide candidate genes responsible for muscle phenotypic variation and are valuable for pig breeding.

Abstract

RNA-Seq technology is widely used to analyze global changes in the transcriptome and investigate the influence on relevant phenotypic traits. Beijing Black pigs show differences in growth rate and meat quality compared to western pig breeds. However, the molecular mechanisms responsible for such phenotypic differences remain unknown. In this study, longissimus dorsi muscles from Beijing Black and Yorkshire pigs were used to construct RNA libraries and perform RNA-seq. Significantly different expressions were observed in 1051 mRNAs, 322 lncRNAs, and 82 circRNAs. GO and KEGG pathway annotation showed that differentially expressed mRNAs participated in skeletal muscle development and fatty acid metabolism, which determined the muscle-related traits. To explore the regulatory role of lncRNAs, the cis and trans-target genes were predicted and these lncRNAswere involved in the biological processes related to skeletal muscle development and fatty acid metabolismvia their target genes. CircRNAs play a ceRNA role by binding to miRNAs. Therefore, the potential miRNAs of differentially expressed circRNAs were predicted and interaction networks among circRNAs, miRNAs, and key regulatory mRNAs were constructed to illustrate the function of circRNAs underlying skeletal muscle development and fatty acid metabolism. This study provides new clues for elucidating muscle phenotypic variation in pigs.

Transcriptome sequencing and characterization of Astragalus membranaceus var. mongholicus root reveals key genes involved in flavonoids biosynthesis

BACKGROUND

Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao is a traditional medicinal herb of Leguminosae since it contains bioactive compounds such as flavonoids, which have significant pharmacological effects on immunity and antioxidant. However, the scanty genomic and transcriptome resources of Astragalus membranaceus have hindered further exploration of its biosynthesis and accumulation mechanism.

OBJECTIVE

This project aim to further improve our understanding of the relationship between transcriptional behavior and flavonoids content of A. mongholicus.

METHODS

The accumulation of flavonoids and related gene expression in five different developmental stages (A: vegetative, B: florescence, C: fruiting, D: fruit ripening and E: defoliating stages) of A. mongholicus root were studied by combining UV spectrophotometry and transcriptomic techniques. The de novo assembly, annotation and functional evaluation of the contigs were performed with bioinformatics tools.

RESULTS

After screening and assembling the raw data, there were a total of 158,123 unigenes with an average length of 644.89 bp were finally obtained, which has 8362 unigenes could be jointly annotated by NR, SwissProt, eggNOG, GO, KEGG and Pfam databases. KEGG enrichment analysis was performed on differentially expressed genes(DEGs)in the four groups (A vs. B, B vs. C, C vs. D, D vs. E). The results showed that many DEGs in each group were significantly enriched to flavonoids biosynthesis related pathways. Among them, a number of 86 were involved in the biosynthesis of isoflavonoid (12), flavonoid (5) and phenylpropanoid (69). Further analysis of these DEGs revealed that the expression levels of key genes such as PAL, 4CL, CCR, COMT, DFR, etc. were all down-regulated at the fruiting stage, and then raised at the fruit ripening stage. This expression pattern was similar to the accumulation trend of total flavonoids content.

CONCLUSIONS

In summary, this comprehensive transcriptome dataset allowed the identification of genes associated with flavonoids metabolic pathways. The results laid a foundation for the biosynthesis and regulation of flavonoids. It also provided a scientific basis for the most suitable harvest time and resource utilization of A. mongholicus.

Proteome interrogation using gold nanoprobes to identify targets of arctigenin in fish parasites

Gold nanoparticles (GNPs) are one of the most widely used nanomaterials in various fields. Especially, the unique chemical and physical properties make them as the promising candidates in drug target identification, unfortunately, little is known about their application in parasites. In this paper, GNPs were employed as new solid support to identify drug targets of natural bioactive compound arctigenin (ARG) against fish monogenean parasite Gyrodactylus kobayashi. Before target identification, GNPs with ARG on the surface showed the ability to enter the live parasites even the nucleus or mitochondria, which made the bound compounds capable of contacting directly with target proteins located anywhere of the parasites. At the same time, chemically modified compound remained the anthelminthic efficacy against G. kobayashii. The above results both provide assurance on the reliability of using GNPs for drug target-binding specificity. Subsequently, by interrogating the cellular proteome in parasite lysate, myosin-2 and UNC-89 were identified as the potential direct target proteins of ARG in G. kobayashii. Moreover, results of RNA-seq transcriptomics and iTRAQ proteomics indicated that myosin-2 expressions were down-regulated after ARG bath treatment both in transcript and protein levels, but for UNC-89, only in mRNA level. Myosin-2 is an important structural muscle protein expressed in helminth tegument and its identification as our target will enable further inhibitor optimization towards future drug discovery. Furthermore, our findings demonstrate the power of GNPs to be readily applied to other parasite drugs of unknown targets, facilitating more broadly therapeutic drug design in any pathogen or disease model.

Caenorhabditis elegans revisited by atomic force microscopy - Ultra-structural changes of the cuticle, but not in the intestine after treatment with Combretum mucronatum extract

Assessing the internal morphology of Caenorhabditis elegans by a topographical technique like atomic force microscopy (AFM) is a challenging process. As a prerequisite for a successful image acquisition, direct contact between the structure of interest and the AFM probe needs to be established. To gain this insight into the morphology of cuticle and intestine in C. elegans before and after treatment with a tannin-enriched hydro-ethanolic extract from Combretum mucronatum, we developed an approach based on polyethylene glycol embedding, ultra-sectioning, de-embedding and hexamethyldisilazane-dehydration prior to measuring in ambient conditions by intermittent contact mode AFM. The used experimental protocol allowed a facile and fast insight into the ultrastructure of treated versus untreated C. elegans individuals, directly leading to the identification of treatment-associated morphological alterations in the cuticle but not the intestine of C. elegans. Additionally, the presented ultra-microtomy based protocol could allow future insight into virtually any tissue or organism by AFM.

Transcriptome analysis reveals differential gene expression in intramuscular adipose tissues of Jinhua and Landrace pigs

Meat is a rich source of protein, fatty acids and carbohydrates for human needs. In addition to necessary nutrients, high fat contents in pork increase the tenderness and juiciness of the meat, featuring diverse application in various dishes. This study investigated the transcriptomic profiles of intramuscular adipose tissues in Jinhua and Landrace pigs by employing advanced RNA sequencing. Results showed significant interesting to note that there were significant differences in the expression of genes. 1,632 genes showed significant differential expression, 837 genes were up-regulated and 195 genes were down-regulated. Variations in genes responsible for cell aggregation, extracellular matrix formation, cellular lipid catabolic process, and fatty acid binding strongly supported that both pig breeds feature variable fat and muscle metabolism. Certain differentially expressed genes are included in the pathway of mitogen-activated protein kinase signaling pathway, Ras signaling pathway and insulin pathway. Results from real-time quantitative polymerase chain reaction also validated the differential expression of 17 mRNAs between meats of the two pig breeds. Overall, these findings reveal significant differences in fat and protein metabolism of intramuscular adipose tissues of two pig breeds at the transcriptomic level and suggest diversification at the genetic level between breeds of the same species.