Yang Y et al. (2015) Korean J Parasitol "Serine proteases of parasitic helminths."

Vallee I, Cheng SP, Liu MY, Yang Y, Boireau P, Cai YN, Wen YJ

[Korean J Parasitol, 2015]

Serine proteases form one of the most important families of enzymes and perform significant functions in a broad range of biological processes, such as intra- and extracellular protein metabolism, digestion, blood coagulation, regulation of development, and fertilization. A number of serine proteases have been identified in parasitic helminths that have putative roles in parasite development and nutrition, host tissues and cell invasion, anticoagulation, and immune evasion. In this review, we described the serine proteases that have been identified in parasitic helminths, including nematodes (Trichinella spiralis, T. pseudospiralis, Trichuris muris, Anisakis simplex, Ascaris suum, Onchocerca volvulus, O. lienalis, Brugia malayi, Ancylostoma caninum, and Steinernema carpocapsae), cestodes (Spirometra mansoni, Echinococcus granulosus, and Schistocephalus solidus), and trematodes (Fasciola hepatica, F. gigantica, and Schistosoma mansoni). Moreover, the possible biological functions of these serine proteases in the endogenous biological phenomena of these parasites and in the host-parasite interaction were also discussed.

Yang, Y. et al. (2009) International Worm Meeting "Role of the MAP Kinase Cascade in the MSP Signaling Response."

Miller, M.A., Yang, Y.

[International Worm Meeting, 2009]

The MSP domain is an evolutionarily conserved immunoglobulin-like structure of about 120 amino acids. A P56S mutation in the MSP domain of the human vapB gene causes a dominantly inherited form of Amyotropic Lateral Sclerosis (ALS) or sometimes Spinal Muscular Atrophy (SMA) (Nishimura et al., 2004). In C. elegans, MSP is the most abundant protein in sperm and is the founding member of MSP domain family. MSP functions as an intracellular cytoskeleton protein and a secreted hormone. Secreted MSP binds to the VAB-1 Eph receptor and other receptors on oocyte and ovarian sheath cell surfaces to induce oocyte maturation and sheath contraction. We have recently shown that worm, fly, and human VAPB MSP domains are secreted ligands for Eph receptors and other receptors. The human VAPB MSP domain is found in blood serum, consistent with a hormonal function. In fly cells, the P56S mutation prevents secretion of the VAPB MSP domain, suggesting that the signaling function is important for ALS and SMA pathogenesis (Tsuda et al., 2008). To better understand how MSP domains transduce signals, I have been studying the PTP-2 tyrosine phosphatase, an SHP homolog that is thought to couple receptor tyrosine kinase (RTK) activation to the MAPK cascade. Previous studies have shown that MSP promotes MPK-1 MAPK phosphorylation during oocyte maturation (Miller et al., 2001) and that PTP-2 is required for normal fertility (Gutch et al., 1998). I have shown that PTP-2 is expressed in the gonad, where it is required for MSP-induced oocyte maturation and MAPK activation, but not MSP-induced sheath contraction. Expressing GFP::PTP-2 specifically in the germ line can partially rescue the oocyte maturation defects, embryonic lethality, and larval lethality of ptp-2 null mutants. Furthermore, these ptp-2 null defects can be rescued by inactivating multiple RAS GAPs, as well as by a RAS gain of function mutation. MSP binding studies show that MSP receptors are present on the oocyte and sheath plasma membranes in ptp-2 null mutants. These results are consistent with a model in which MSP regulates the activity of a canonical RTK/MAPK pathway to induce oocyte maturation. The identity of the RTK is not known and it is not clear whether MSP regulates RTK activation through a direct interaction (i.e. the RTK is an MSP receptor) or indirectly. VAPB homologs may also regulate the MAPK pathway because PTP-2 is expressed in muscle and loss of PTP-2 causes muscle mitochondrial defects that are similar to loss of worm VAPB (called VPR-1).

Yang Y et al. (2013) Vet Parasitol "TsDAF-21/Hsp90 is expressed in all examined stages of Trichinella spiralis."

Tian G, Qin W, Cao L, Yang Y, Zarlenga D

[Vet Parasitol, 2013]

Trichinella is an important parasitic nematode of animals worldwide. Heat shock proteins are ubiquitous in nature and allow organisms to quickly respond to environmental stress. A portion of the Tsdaf-21 gene, a Caenorhabditis elegans daf-21 homologue encoding heat-shock protein 90 (Hsp90) was cloned from Trichinella spiralis. The partial nucleotide sequence resided near the 5'-end of the gene and encoded a polypeptide of 254 amino acid residues harboring a HATPase-c superfamily domain and Hsp90 protein domain. Phylogenetic analysis revealed that Tsdaf-21 is highly conserved and formed a monophyletic clade with other nematodes. The partial Tsdaf-21 transcript was subcloned and expressed for antibody production. Results using PCR primers specific for the Tsdaf-21 transcript, and mouse polyclonal antisera specific for the recombinant protein showed that both the RNA transcript and the corresponding protein were ubiquitously and consistently expressed in newborn larvae, muscle larvae and both male and female adult worms in the absence of any external stress or stimulation.

Yang Y et al. (2020) Ecotoxicol Environ Saf "Epigenetic response to nanopolystyrene in germline of nematode Caenorhabditis elegans."

Wu Q, Yang Y, Wang D

[Ecotoxicol Environ Saf, 2020]

microRNAs (miRNAs) provide an epigenetic regulation mechanism for the response to environmental toxicants. mir-38, a germline miRNA, was increased by exposure to nanopolystyrene (100nm). In this study, we further found that germline overexpression of mir-38 decreased expressions of nhl-2 encoding a miRISC cofactor, ndk-1 encoding a homolog of NM23-H1, and wrt-3 encoding a homolog of PPIL-2. Meanwhile, germline-specific RNAi knockdown of nhl-2, ndk-1, or wrt-3 caused the resistance to nanopolystyrene toxicity. Additionally, mir-38 overexpression suppressed the resistance of nematodes overexpressing germline nhl-2, ndk-1, or wrt-3 containing 3'UTR, suggesting the role of NHL-2, NDK-1, and WRT-3 as the targets of germline mir-38 in regulating the response to nanopolystyrene. Moreover, during the control of response to nanopolystyrene, EKL-1, a Tudor domain protein, was identified as the downstream target of germline NHL-2, kinase suppressors of Ras (KSR-1 and KSR-2) were identified as the downstream targets of germline NDK-1, and ASP-2, a homolog of BACE1, was identified as the downstream target of germline WRT-3. Our results raised a mir-38-mediated molecular network in the germline in response to nanopolystyrene in nematodes. Our data provided an important basis for our understanding the response of germline of organisms to nanoplastic exposure.

Yang Y et al. (2019) Environ Pollut "Lipid metabolic response to polystyrene particles in nematode Caenorhabditis elegans."

Wu Q, Shao H, Yang Y, Wang D

[Environ Pollut, 2019]

Nanoplastics can be used in various fields, such as personal care products. Nevertheless, the effect of nanoplastic exposure on metabolism and its association with stress response remain largely unclear. Using Caenorhabditis elegans as an animal model, we determined the effect of nanopolystyrene exposure on lipid metabolism and its association with the response to nanopolystyrene. Exposure (from L1-larave to adult day-3) to 100nm nanopolystyrene (1g/L) induced severe lipid accumulation and increase in expressions of mdt-15 and sbp-1 encoding two lipid metabolic sensors. Meanwhile, we found that SBP-1 acted downstream of intestinal MDT-15 during the control of response to nanopolystyrene. Intestinal transcriptional factor SBP-1 activated two downstream targets, fatty acyl CoA desaturase FAT-6 and heat-shock protein HSP-4 (a marker of endoplasmic reticulum unfolded protein response (ER UPR)) to regulate nanopolystyrene toxicity. Both MDT-15 and SBP-1 were involved in the activation of ER-UPR in nanopolystyrene exposed nematodes. Moreover, SBP-1 regulated the innate immune response by activating FAT-6 in nanopolystyrene exposed nematodes. In the intestine, function of MDT-15 and SBP-1 in regulating nanopolystyrene toxicity was under the control of upstream signaling cascade (PMK-1-SKN-1) in p38 MAPK signaling pathway. Therefore, our data raised an important molecular basis for potential protective function of lipid metabolic response in nanopolystyrene exposed nematodes.

Yang Y et al. (2018) Sci Total Environ "Effects of ionic strength on physicochemical properties and toxicity of silver nanoparticles."

Chen S, Wu L, Liu R, Xu S, Xu A, Xu G, Yang Y

[Sci Total Environ, 2018]

In the environment, silver nanoparticles (AgNPs) undergo a number of potential transformations, such as aggregation, dissolution, and redox reactions. However, the transformation in ionic strength condition, as well as their related toxicity was not quite clear, especially in the in vivo system. In the present study, we comprehensively evaluated three different characteristics (ddH₂O, EPA water and K⁺ medium (KM)) mediated changes in the physical morphology of AgNPs and the alteration of the toxicity to Caenorhabditis elegans (C. elegans). Our results showed besides the changes of AgNPs behavior such as the transformation of morphological, with the transmission electron microscopy we found for the first time that smaller nanoparticles (<5nm) appeared around the pristine AgNPs after incubation in EPA or KM for 5days. Together with these changes, the toxicity of AgNPs to C. elegans changed significantly, showing that a higher ionic strength medium resulted in greater toxicity to C. elegans, as measured by germ cell apoptosis, brood size and lifespan. More importantly, our results indicated that the higher toxicity of AgNPs to C. elegans reproduction was probably related to the appearance of the smaller-size AgNPs in higher ionic strength media. These findings highlight that toxicity assessments for the release of nanomaterial to the environment need to be improved to assess environmental safety more accurately.

Yang Y et al. (2021) Nanoscale Adv "Response of G protein-coupled receptor CED-1 in germline to polystyrene nanoparticles in Caenorhabditis elegans."

Dong W, Yang Y, Wu Q, Wang D

[Nanoscale Adv, 2021]

The deposition of a certain amount of nanopolystyrene (NPS) can be observed in the gonad of Caenorhabditis elegans. However, we still know little about the response of germline towards NPS exposure. In the germline of C. elegans, NPS (1-1000 μg L-1) increased the expression levels of two G protein-coupled receptors (GPCRs), namely PAQR-2 and CED-1. Moreover, susceptibility to NPS toxicity was observed in ced-1(RNAi) worms, which suggested that the protective response of germline was mediated by GPCR CED-1. In the germline, five proteins (CED-10, VPS-34, SNX-1, RAB-7, and RAB-14) functioned as downstream targets of GPCR CED-1 in controlling NPS toxicity. Furthermore, these five targets in the germline regulated NPS toxicity by affecting the activities of p38 MAPK and insulin signaling pathways in intestinal cells. Therefore, we raised a GPCR CED-1-mediated signaling cascade in the germline in response to NPS exposure, which is helpful for understanding the molecular basis of the germline in response to NPS exposure.

Yang Y et al. (2003) J Biol Chem "Genetic interaction between a chaperone of small nucleolar ribonucleoprotein particles and cytosolic serine hydroxymethyltransferase."

Meier UT, Yang Y

[J Biol Chem, 2003]

Srp40p is a nonessential yeast nucleolar protein proposed to function as a chaperone for over 100 small nucleolar ribonucleoprotein particles that are required for rRNA maturation. To verify and expand on its function, genetic screens were performed for the identification of genes that were lethal when mutated in a SRP40 null background (srp40Delta). Unexpectedly, mutation of both cytosolic serine hydroxymethyltransferase (SHM2) and one-carbon tetrahydrofolate synthase (ADE3) was required to achieve synthetic lethality with srp40Delta. Shm2p and Ade3p are cytoplasmic enzymes producing 5,10-methylene tetrahydrofolate in convergent pathways as the primary source for cellular one-carbon groups. Nonetheless, point mutants of Shm2p that were catalytically inactive (i.e. failed to rescue the methionine auxotrophy of a shm2Delta ade3 strain) complemented the synthetic lethal phenotype, thus revealing a novel metabolism-independent function of Shm2p. The same Shm2p mutants exacerbated a giant cell phenotype observed in the shm2Delta ade3 strain suggesting a catalysis-independent role for Shm2p in cell size control, possibly through regulation of ribosome biogenesis via SRP40. Additionally, we show that the Sm-like protein Lsm5p, which as part of Lsm complexes participates in cytosolic and nuclear RNA processing and degradation pathways, is a multicopy suppressor of the synthetic lethality and of the specific depletion of box H/ACA small nucleolar RNAs from the srp40Delta shm2 ade3 strain. Finally, rat Nopp140 restored growth and stability of box H/ACA snoRNAs after genetic depletion of SRP40 in the synthetic lethal strain indicating that it is indeed the functional homolog of yeast Srp40p.

Yang Y et al. (2010) Parasitol Res "Expression and functional characterization of a Rho-family small GTPase CDC42 from Trichinella spiralis."

Tian G, Yang Y, Qin W, Jian W

[Parasitol Res, 2010]

A full-length cDNA encoding a Rho-family small GTPase gene cdc42 of Trichinella spiralis was expressed in E. coli. The recombinant protein of TsCDC42 was purified and used to raise the polyclonal antibodies. The expression of TsCDC42 in different stages of parasite was investigated. The western blot showed that TsCDC42 was expressed in all stages of T. spiralis, including newborn larvae, muscle larvae and adult worms. The immuno-localization revealed that TsCDC42 was ubiquitously distributed in the newborn larvae, muscle larvae and adult worm. Cross-species RNAi was done by knockdown Tscdc42 RNAi in C. elegans. The results revealed that endogenous expression level of CDC42 was decreased by knockdown Tscdc42 RNAi in C. elegans, and this knockdown reduced the progeny of C. elegans. It suggested that Tscdc42 might play the same roles in the early development of T. spiralis.

Yang Y et al. (2013) Gene "Characterization of TsMRP-L28, a mitochondrial ribosomal protein L28 from the parasitic nematode Trichinella spiralis."

Yang Y, Tian G, Qin W, Jian W

[Gene, 2013]

A cDNA encoding mitochondrial ribosomal protein (MRP)-L28 was isolated and cloned from Trichinella spiralis, an economically important parasitic nematode. The predicted TsMRP-L28 protein consists of 276 amino acids. Phylogenetic analysis revealed that TsMRP-L28 was closely related to Caenorhabditis elegans mitochondrial ribosomal protein L28. The TsMRP-L28 transcript was expressed in newborn larvae, muscle larvae and male and female adult worms. Western blot showed that TsMRP-L28 was expressed in muscle larvae and adult worms. Immuno-localization revealed that TsMRP-L28 was ubiquitously distributed in newborn larvae, muscle larvae and adult worms, and that TsMRP-L28 was enriched in cells with higher protein synthesis activity, such as in newborn larvae and the cytoplasm of different developmental stages of embryos. These data suggest that TsMRP-L28 is required for the early development of T. spiralis.