scholarly journals Schistosoma mansoni α-N-acetylgalactosaminidase (SmNAGAL) regulates coordinated parasite movement and egg production

2022 ◽  
Vol 18 (1) ◽  
pp. e1009828
Author(s):  
Benjamin J. Hulme ◽  
Kathrin K. Geyer ◽  
Josephine E. Forde-Thomas ◽  
Gilda Padalino ◽  
Dylan W. Phillips ◽  
...  

α-galactosidase (α-GAL) and α-N-acetylgalactosaminidase (α-NAGAL) are two glycosyl hydrolases responsible for maintaining cellular homeostasis by regulating glycan substrates on proteins and lipids. Mutations in the human genes encoding either enzyme lead to neurological and neuromuscular impairments seen in both Fabry- and Schindler/Kanzaki- diseases. Here, we investigate whether the parasitic blood fluke Schistosoma mansoni, responsible for the neglected tropical disease schistosomiasis, also contains functionally important α-GAL and α-NAGAL proteins. As infection, parasite maturation and host interactions are all governed by carefully-regulated glycosylation processes, inhibiting S. mansoni’s α-GAL and α-NAGAL activities could lead to the development of novel chemotherapeutics. Sequence and phylogenetic analyses of putative α-GAL/α-NAGAL protein types showed Smp_089290 to be the only S. mansoni protein to contain the functional amino acid residues necessary for α-GAL/α-NAGAL substrate cleavage. Both α-GAL and α-NAGAL enzymatic activities were higher in females compared to males (p<0.05; α-NAGAL > α-GAL), which was consistent with smp_089290’s female biased expression. Spatial localisation of smp_089290 revealed accumulation in parenchymal cells, neuronal cells, and the vitellaria and mature vitellocytes of the adult schistosome. siRNA-mediated knockdown (>90%) of smp_089290 in adult worms significantly inhibited α-NAGAL activity when compared to control worms (siLuc treated males, p<0.01; siLuc treated females, p<0.05). No significant reductions in α-GAL activities were observed in the same extracts. Despite this, decreases in α-NAGAL activities correlated with a significant inhibition in adult worm motility as well as in egg production. Programmed CRISPR/Cas9 editing of smp_089290 in adult worms confirmed the egg reduction phenotype. Based on these results, Smp_089290 was determined to act predominantly as an α-NAGAL (hereafter termed SmNAGAL) in schistosome parasites where it participates in coordinating movement and oviposition processes. Further characterisation of SmNAGAL and other functionally important glycosyl hydrolases may lead to the development of a novel anthelmintic class of compounds.

2021 ◽  
Author(s):  
Benjamin Hulme ◽  
Kathrin Geyer ◽  
Josephine Forde-Thomas ◽  
Gilda Padalino ◽  
Dylan Phillips ◽  
...  

α-galactosidase (α-GAL) and α-N-acetylgalactosaminidase (α-NAGAL) are two glycosyl hydrolases responsible for maintaining cellular homeostasis by regulating glycan substrates on proteins and lipids. Mutations in the human genes encoding either enzyme lead to neurological and neuromuscular impairments seen in both Fabry- and Schindler/Kanzaki- diseases. Here, we investigate whether the parasitic blood fluke Schistosoma mansoni, responsible for the neglected tropical disease schistosomiasis, also contains functionally important α-GAL and α-NAGAL proteins. As infection, parasite maturation and host interactions are all governed by carefully-regulated glycosylation processes, inhibiting S. mansoni’s α-GAL and α-NAGAL activities could lead to the development of novel chemotherapeutics. Sequence and phylogenetic analyses of putative α-GAL/α-NAGAL protein types showed Smp_089290 to be the only S. mansoni protein to contain the functional amino acid residues necessary for α-GAL/α-NAGAL substrate cleavage. Both α-GAL and α-NAGAL enzymatic activities were higher in females compared to males (p<0.05; α-NAGAL > α-GAL), which was consistent with smp_089290’s female biased expression. Spatial localisation of smp_089290 revealed accumulation in parenchymal cells, neuronal cells, and the vitellaria and mature vitellocytes of the adult schistosome. siRNA-mediated knockdown (>90%) of smp_089290 in adult worms significantly inhibited α-NAGAL activity when compared to control worms (siLuc treated males, p<0.01; siLuc treated females, p<0.05). No significant reductions in α-GAL activities were observed in the same extracts. Despite this, decreases in α-NAGAL activities correlated with a significant inhibition in adult worm motility as well as in egg production. Programmed CRISPR/Cas9 editing of smp_089290 in adult worms confirmed the egg reduction phenotype. Based on these results, Smp_089290 was determined to act predominantly as an α-NAGAL (hereafter termed SmNAGAL) in schistosome parasites where it participates in coordinating movement and oviposition processes. Pharmacological inhibition of SmNAGAL may lead to the development of a novel anthelmintic class of compounds.


1996 ◽  
Vol 318 (1) ◽  
pp. 133-138 ◽  
Author(s):  
Roberto A GEREMIA ◽  
E Alejandro PETRONI ◽  
Luis IELPI ◽  
Bernard HENRISSAT

A number of genes encoding bacterial glycosyltransferases have been sequenced during the last few years, but their low sequence similarity has prevented a straightforward grouping of these enzymes into families. The sequences of several bacterial α-mannosyltransferases have been compared using current alignment algorithms as well as hydrophobic cluster analysis (HCA). These sequences show a similarity which is significant but too low to be reliably aligned using automatic alignment methods. However, a region spanning approx. 270 residues in these proteins could be aligned by HCA, and several invariant amino acid residues were identified. These features were also found in several other glycosyltransferases, as well as in proteins of unknown function present in sequence databases. This similarity most probably reflects the existence of a family of proteins with conserved structural and mechanistic features. It is argued that the present IUBMB classification of glycosyltransferases could be complemented by a classification of these enzymes based on sequence similarities analogous to that which we proposed for glycosyl hydrolases [Henrissat, B. (1991) Biochem. J. 280, 309–316].


2021 ◽  
Vol 17 (12) ◽  
pp. e1009087 ◽  
Author(s):  
Crispin Zavala-Alvarado ◽  
Samuel G. Huete ◽  
Antony T. Vincent ◽  
Odile Sismeiro ◽  
Rachel Legendre ◽  
...  

Pathogenic Leptospira are the causative agents of leptospirosis, the most widespread zoonotic infectious disease. Leptospirosis is a potentially severe and life-threatening emerging disease with highest burden in sub-tropical areas and impoverished populations. Mechanisms allowing pathogenic Leptospira to survive inside a host and induce acute leptospirosis are not fully understood. The ability to resist deadly oxidants produced by the host during infection is pivotal for Leptospira virulence. We have previously shown that genes encoding defenses against oxidants in L. interrogans are repressed by PerRA (encoded by LIMLP_10155), a peroxide stress regulator of the Fur family. In this study, we describe the identification and characterization of another putative PerR-like regulator (LIMLP_05620) in L. interrogans. Protein sequence and phylogenetic analyses indicated that LIMLP_05620 displayed all the canonical PerR amino acid residues and is restricted to pathogenic Leptospira clades. We therefore named this PerR-like regulator PerRB. In L. interrogans, the PerRB regulon is distinct from that of PerRA. While a perRA mutant had a greater tolerance to peroxide, inactivating perRB led to a higher tolerance to superoxide, suggesting that these two regulators have a distinct function in the adaptation of L. interrogans to oxidative stress. The concomitant inactivation of perRA and perRB resulted in a higher tolerance to both peroxide and superoxide and, unlike the single mutants, a double perRAperRB mutant was avirulent. Interestingly, this correlated with major changes in gene and non-coding RNA expression. Notably, several virulence-associated genes (clpB, ligA/B, and lvrAB) were repressed. By obtaining a double mutant in a pathogenic Leptospira strain, our study has uncovered an interplay of two PerRs in the adaptation of Leptospira to oxidative stress with a putative role in virulence and pathogenicity, most likely through the transcriptional control of a complex regulatory network.


Parasitology ◽  
1994 ◽  
Vol 108 (3) ◽  
pp. 301-311 ◽  
Author(s):  
J. M. Solis-soto ◽  
M. De Jong Brink

SUMMARYImmunocytochemical techniques applied to sections and whole-mount preparations of cercariae from two species of trematodes, Trichobilharzia ocellata and Schistosoma mansoni, revealed the occurrence of immunoreactivity (IR) to several neurosubstances in the nervous system (NS). Immunostaining was localized in cerebral ganglia, in the main commissure, in anterior and posterior nerve trunks, as well as in a pair of nerve fibres running along the tail. In T. Ocellata, immunoreactivity (IR) was observed with antisera raised against: glutamate, FMRFamide, catch-relaxing peptide (CARP), small cardiac peptide B (SCPB), arg-vasotocin (AVT), arg-vasopressin (AVP), and substance P. In S. mansoni antisera raised against glutamate, FMRFamide, CARP, SCPB, α-caudodorsal cell peptides (α-CDCP), and cholecystokinin (CCK) showed neuronal IR. With the other 51 antisera tested no IR was observed. With anti-APGWamide, IR was observed outside the NS in cells of the wall of the daughter sporocyst and in flame cells of cercariae of T. ocellata. IR to FMRFamide was present in the escape glands of the intrasporocystic cercariae of T. ocellata and S. mansoni. IR to somatostatin was observed in subtegumental parenchymal cells of cercariae of S. mansoni. IR to met-enkephalin was present in cells of the cercarial embryos and in undifferentiated cells in developing cercariae. Trematodes are, together with cestodes, phylogenetically the oldest classes in which glutamate-like material and immunopositivity to a number of neuropeptides isolated from invertebrates has been demonstrated. The results are discussed in relation to immunocytochemical data obtained for other platyhelminths, to endogenous functions of the immunopositive materials, and to their possible role in parasite–host interactions.


2018 ◽  
Author(s):  
Michiel L. Bexkens ◽  
Mirjam M. Mebius ◽  
Martin Houweling ◽  
Jos F. Brouwers ◽  
Aloysius G.M. Tielens ◽  
...  

AbstractAdult schistosomes, parasitic flatworms that cause the tropical disease schistosomiasis, have always been considered to be homolactic fermenters and in their energy metabolism strictly dependent on carbohydrates. However, more recent studies suggested that fatty acid β-oxidation is essential for egg production by adult female Schistosoma mansoni. To address this conundrum, we performed a comprehensive study on the lipid metabolism of S. mansoni. Incubations with [14C]-labelled fatty acids demonstrated that adults, eggs and miracidia of S. mansoni did not oxidize fatty acids, as no 14CO2 production could be detected. We then re-examined the S. mansoni genome using the genes known to be involved in fatty acid oxidation in six eukaryotic model reference species. This showed that the earlier automatically annotated genes for fatty acid oxidation were in fact incorrectly annotated. In a further analysis we could not detect any genes encoding β-oxidation enzymes, which demonstrates that S. mansoni cannot use this pathway in any of its lifecycle stages. The same was true for S. japonicum. Absence of β-oxidation, however, does not imply that fatty acids from the host are not metabolized by schistosomes. Adult schistosomes can use and modify fatty acids from their host for biosynthetic purposes and incorporate them in phospholipids and neutral lipids. Female worms deposit large amounts of these lipids in the eggs they produce, which explains why interference with the lipid metabolism in females will disturb egg formation, even though fatty acid β-oxidation does not occur in schistosomes. Our analyses of S. mansoni further revealed that during the development and maturation of the miracidium inside the egg, changes in lipid composition occur which indicates that fatty acids deposited in the egg by the female worm are used for phospholipid biosynthesis required for membrane formation in the developing miracidium.


2009 ◽  
Vol 76 (4) ◽  
pp. 994-998 ◽  
Author(s):  
Pannipa Prompiboon ◽  
Verena-Ulrike Lietze ◽  
John S. S. Denton ◽  
Christopher J. Geden ◽  
Tove Steenberg ◽  
...  

ABSTRACT The housefly, Musca domestica, is a cosmopolitan pest of livestock and poultry and is of economic, veterinary, and public health importance. Populations of M. domestica are naturally infected with M. domestica salivary gland hypertrophy virus (MdSGHV), a nonoccluded double-stranded DNA virus that inhibits egg production in infected females and is characterized by salivary gland hypertrophy (SGH) symptoms. MdSGHV has been detected in housefly samples from North America, Europe, Asia, the Caribbean, and the southwestern Pacific. In this study, houseflies were collected from various locations and dissected to observe SGH symptoms, and infected gland pairs were collected for MdSGHV isolation and amplification in laboratory-reared houseflies. Differences among the MdSGHV isolates were examined by using molecular and bioassay approaches. Approximately 600-bp nucleotide sequences from each of five open reading frames having homology to genes encoding DNA polymerase and partial homology to the genes encoding four per os infectivity factor proteins (p74, pif-1, pif-2, and pif-3) were selected for phylogenetic analyses. Nucleotide sequences from 16 different geographic isolates were highly homologous, and the polymorphism detected was correlated with geographic source. The virulence of the geographic MdSGHV isolates was evaluated by per os treatment of newly emerged and 24-h-old houseflies with homogenates of infected salivary glands. In all cases, 24-h-old flies displayed a resistance to oral infection that was significantly greater than that displayed by newly eclosed adults. Regardless of the MdSGHV isolate tested, all susceptible insects displayed similar degrees of SGH and complete suppression of oogenesis.


Diabetes ◽  
1996 ◽  
Vol 45 (2) ◽  
pp. 267-269 ◽  
Author(s):  
N. Iwasaki ◽  
M. Kawamura ◽  
K. Yamagata ◽  
N. J. Cox ◽  
S. Karibe ◽  
...  

1990 ◽  
Vol 265 (28) ◽  
pp. 17267-17273 ◽  
Author(s):  
B T Archer ◽  
T Ozçelik ◽  
R Jahn ◽  
U Francke ◽  
T C Südhof
Keyword(s):  

Author(s):  
Annika S. Mokosch ◽  
Stefanie Gerbig ◽  
Christoph G. Grevelding ◽  
Simone Haeberlein ◽  
Bernhard Spengler

AbstractSchistosoma mansoni is a parasitic flatworm causing schistosomiasis, an infectious disease affecting several hundred million people worldwide. Schistosomes live dioeciously, and upon pairing with the male, the female starts massive egg production, which causes pathology. Praziquantel (PZQ) is the only drug used, but it has an inherent risk of resistance development. Therefore, alternatives are needed. In the context of drug repurposing, the cancer drug imatinib was tested, showing high efficacy against S. mansoni in vitro. Besides the gonads, imatinib mainly affected the integrity of the intestine in males and females. In this study, we investigated the potential uptake and distribution of imatinib in adult schistosomes including its distribution kinetics. To this end, we applied for the first time atmospheric-pressure scanning microprobe matrix-assisted laser desorption/ionization mass spectrometry imaging (AP-SMALDI MSI) for drug imaging in paired S. mansoni. Our results indicate that imatinib was present in the esophagus and intestine of the male as early as 20 min after in vitro exposure, suggesting an oral uptake route. After one hour, the drug was also found inside the paired female. The detection of the main metabolite, N-desmethyl imatinib, indicated metabolization of the drug. Additionally, a marker signal for the female ovary was successfully applied to facilitate further conclusions regarding organ tropism of imatinib. Our results demonstrate that AP-SMALDI MSI is a useful method to study the uptake, tissue distribution, and metabolization of imatinib in S. mansoni. The results suggest using AP-SMALDI MSI also for investigating other antiparasitic compounds and their metabolites in schistosomes and other parasites. Graphical abstract


Sign in / Sign up

Export Citation Format

Share Document