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Trends in Parasitology Aug 2023Arguably the most unique biological features of trematode parasites involve their clonal parthenitae and cercariae. These life stages are biologically fascinating,... (Review)
Review
Arguably the most unique biological features of trematode parasites involve their clonal parthenitae and cercariae. These life stages are biologically fascinating, medically and scientifically important, and often studied for years, lacking knowledge of their corresponding sexual adult stages. But sexual adults are the focus of trematode species-level taxonomy, partially explaining the relative neglect of documenting the diversity of parthenitae and cercariae and why researchers who do describe them give them only provisional names. Provisional names are unregulated, unstable, often ambiguous, and, I argue, often unnecessary. I suggest that we recommence formally naming parthenitae and cercariae using an improved naming scheme. The scheme should permit us to reap the benefits of formal nomenclature and thereby enhance research involving these diverse and important parasites.
Topics: Animals; Larva; Snails; Trematoda
PubMed: 37385923
DOI: 10.1016/j.pt.2023.05.011 -
Frontiers in Cellular and Infection... 2023
Topics: Animals; Host-Pathogen Interactions; Cestoda
PubMed: 37767200
DOI: 10.3389/fcimb.2023.1283267 -
International Journal of Molecular... Jan 2024Control of schistosomiasis japonica, endemic in Asia, including the Philippines, China, and Indonesia, is extremely challenging. is a highly pathogenic helminth... (Review)
Review
Control of schistosomiasis japonica, endemic in Asia, including the Philippines, China, and Indonesia, is extremely challenging. is a highly pathogenic helminth parasite, with disease arising predominantly from an immune reaction to entrapped parasite eggs in tissues. Females of this species can generate 1000-2200 eggs per day, which is about 3- to 15-fold greater than the egg output of other schistosome species. Bovines (water buffalo and cattle) are the predominant definitive hosts and are estimated to generate up to 90% of parasite eggs released into the environment in rural endemic areas where these hosts and humans are present. Here, we highlight the necessity of developing veterinary transmission-blocking vaccines for bovines to better control the disease and review potential vaccine candidates. We also point out that the approach to producing efficacious transmission-blocking animal-based vaccines before moving on to human vaccines is crucial. This will result in effective and feasible public health outcomes in agreement with the One Health concept to achieve optimum health for people, animals, and the environment. Indeed, incorporating a veterinary-based transmission vaccine, coupled with interventions such as human mass drug administration, improved sanitation and hygiene, health education, and snail control, would be invaluable to eliminating zoonotic schistosomiasis.
Topics: Animals; Female; Cattle; Humans; Schistosomiasis japonica; Schistosoma japonicum; Vaccines; Schistosomiasis; Vaccination; China; Buffaloes
PubMed: 38338980
DOI: 10.3390/ijms25031707 -
Zoological Research Sep 2023Planarians represent the most primitive bilateral triploblastic animals. Most planarian species exhibit mechanisms for whole-body regeneration, exemplified by the... (Review)
Review
Planarians represent the most primitive bilateral triploblastic animals. Most planarian species exhibit mechanisms for whole-body regeneration, exemplified by the regeneration of their cephalic ganglion after complete excision. Given their robust whole-body regeneration capacity, planarians have been model organisms in regenerative research for more than 240 years. Advancements in research tools and techniques have progressively elucidated the mechanisms underlying planarian regeneration. Accurate cell-cell communication is recognized as a fundamental requirement for regeneration. In recent decades, mechanisms associated with such communication have been revealed at the cellular level. Notably, stem cells (neoblasts) have been identified as the source of all new cells during planarian homeostasis and regeneration. The interplay between neoblasts and somatic cells affects the identities and proportions of various tissues during homeostasis and regeneration. Here, this review outlines key discoveries regarding communication between stem cell compartments and other cell types in planarians, as well as the impact of communication on planarian regeneration. Additionally, this review discusses the challenges and potential directions of future planarian research, emphasizing the sustained impact of this field on our understanding of animal regeneration.
Topics: Animals; Planarians; Stem Cells; Cell Communication; Homeostasis; Regeneration
PubMed: 37721107
DOI: 10.24272/j.issn.2095-8137.2023.044 -
Cellular and Molecular Gastroenterology... 2024Schistosomiasis is one of the most prominent parasite-induced infectious diseases, affecting more than 250 million people. Schistosoma mansoni causes metabolic...
BACKGROUND & AIMS
Schistosomiasis is one of the most prominent parasite-induced infectious diseases, affecting more than 250 million people. Schistosoma mansoni causes metabolic exhaustion and a strong redox imbalance in the liver, causing parenchymal damage, and may predispose for cancer. We investigated whether oxidative stress provokes hepatocellular proliferation upon S. mansoni infection.
METHODS
The cell cycle, replication stress response, and proliferation were analyzed on transcriptional and protein levels in the livers of S. mansoni-infected hamsters and by mechanistic gain- and loss-of-function experiments in human hepatoma cells. Major results were validated in human biopsy specimens of S. mansoni-infected patients.
RESULTS
S. mansoni infection induced licensing factors of DNA replication and cell-cycle checkpoint cyclins in parallel with a DNA damage response in hamster hepatocytes. Moreover, even unisexual infection without egg effects, as a reflection of a chronic inflammatory process, resulted in a moderate activation of several cell-cycle markers. S. mansoni soluble egg antigens induced proliferation of human hepatoma cells that could be abolished by reduced glutathione.
CONCLUSIONS
Our data suggest that hepatocellular proliferation is triggered by S. mansoni egg-induced oxidative stress.
Topics: Cricetinae; Animals; Humans; Schistosoma mansoni; Schistosomiasis mansoni; Carcinoma, Hepatocellular; Liver Neoplasms; Oxidative Stress; Cell Proliferation
PubMed: 37696392
DOI: 10.1016/j.jcmgh.2023.08.014 -
EBioMedicine Sep 2023Regulatory T cells (Tregs) can alleviate the development of autoimmune and inflammatory diseases, thereby proposing their role as a new therapeutic strategy. Parasitic...
BACKGROUND
Regulatory T cells (Tregs) can alleviate the development of autoimmune and inflammatory diseases, thereby proposing their role as a new therapeutic strategy. Parasitic helminths have co-evolved with hosts to generate immunological privilege and immune tolerance through inducing Tregs. Thus, constructing a "Tregs-induction"-based discovery pipeline from parasitic helminth is a promising strategy to control autoimmune and inflammatory diseases.
METHODS
The gel filtration chromatography and reverse-phase high-performance liquid chromatography (RP-HPLC) were used to isolate immunomodulatory components from the egg extracts of Schistosoma japonicum. The extracted peptides were evaluated for their effects on Tregs suppressive functions using flow cytometry, ELISA and T cell suppression assay. Finally, we carried out colitis and psoriasis models to evaluate the function of Tregs induced by helminth-derived peptide in vivo.
FINDINGS
Here, based on target-driven discovery strategy, we successfully identified a small 3 kDa peptide (SjDX5-53) from egg extracts of schistosome, which promoted both human and murine Tregs production. SjDX5-53 presented immunosuppressive function by arresting dendritic cells (DCs) at an immature state and augmenting the proportion and suppressive capacity of Tregs. In mouse models, SjDX5-53 protected mice against autoimmune-related colitis and psoriasis through inducing Tregs and inhibiting inflammatory T-helper (Th) 1 and Th17 responses.
INTERPRETATION
SjDX5-53 exhibited the promising therapeutic effects in alleviating the phenotype of immune-related colitis and psoriasis. This study displayed a screening and validation pipeline of the inducer of Tregs from helminth eggs, highlighting the discovery of new biologics inspired by co-evolution of hosts and their parasites.
FUNDING
This study was supported by the Natural Science Foundation of China (82272368) and Natural Science Foundation of Jiangsu Province (BK20211586).
Topics: Mice; Humans; Animals; Schistosoma japonicum; T-Lymphocytes, Regulatory; Autoimmune Diseases; Colitis; Psoriasis
PubMed: 37579625
DOI: 10.1016/j.ebiom.2023.104751 -
Bsep/Abcb11 knockout ameliorates Schistosoma mansoni liver pathology by reducing parasite fecundity.Liver International : Official Journal... Nov 2023Schistosoma mansoni infection is one of the worldwide leading causes of liver fibrosis and portal hypertension. The objective of this study was to evaluate whether...
BACKGROUND AND AIMS
Schistosoma mansoni infection is one of the worldwide leading causes of liver fibrosis and portal hypertension. The objective of this study was to evaluate whether polyhydroxylated bile acids (BAs), known to protect mice from the development of acquired cholestatic liver injury, counteract S. mansoni-induced inflammation and fibrosis.
METHODS
Adult FVB/N wild type (WT) and Abcb11/Bsep mice were infected with either 25 or 50 S. mansoni cercariae. Eight weeks post infection, effects on liver histology, serum biochemistry, gene expression profile of proinflammatory cytokines and fibrotic markers, hepatic hydroxyproline content and FACS analysis were performed.
RESULTS
Bsep mice infected with S. mansoni showed significantly less hepatic inflammation and tendentially less fibrosis compared to infected WT mice. Despite elevated alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase levels in infected Bsep mice, inflammatory cells such as M2 macrophages and Mac-2/galectin-3 cells were reduced in these animals. Accordingly, mRNA-expression levels of anti-inflammatory cytokines (IL-4 and IL-13) were increased in Bsep mice upon infection. Furthermore, infected Bsep mice exhibited decreased hepatic egg load and parasite fecundity, consequently affecting the worm reproduction rate. This outcome could arise from elevated serum BA levels and lower blood pH in Bsep mice.
CONCLUSIONS
The loss of Bsep and the resulting changes in bile acid composition and blood pH are associated with the reduction of parasite fecundity, thus attenuating the development of S. mansoni-induced hepatic inflammation and fibrosis.
Topics: Animals; Mice; Bile Acids and Salts; Cytokines; Fertility; Inflammation; Liver; Liver Cirrhosis; Parasites; Schistosoma mansoni; Schistosomiasis mansoni
PubMed: 37641872
DOI: 10.1111/liv.15710 -
PLoS Pathogens Jul 2023Schistosomiasis, a severe parasitic disease, is primarily caused by Schistosoma mansoni, Schistosoma japonicum, or Schistosoma haematobium. Currently, praziquantel is... (Review)
Review
Schistosomiasis, a severe parasitic disease, is primarily caused by Schistosoma mansoni, Schistosoma japonicum, or Schistosoma haematobium. Currently, praziquantel is the only recommended drug for human schistosome infection. However, the lack of efficacy of praziquantel against juvenile worms and concerns about the emergence of drug resistance are driving forces behind the research for an alternative medication. Schistosomes are obligatory parasites that survive on nutrients obtained from their host. The ability of nutrient uptake depends on their physiological structure. In short, the formation and maintenance of the structure and nutrient supply are mutually reinforcing and interdependent. In this review, we focus on the structural features of the tegument, esophagus, and intestine of schistosomes and their roles in nutrient acquisition. Moreover, we introduce the significance and modes of glucose, lipids, proteins, and amino acids intake in schistosomes. We linked the schistosome structure and nutrient supply, introduced the currently emerging targets, and analyzed the current bottlenecks in the research and development of drugs and vaccines, in the hope of providing new strategies for the prevention and control of schistosomiasis.
Topics: Animals; Humans; Praziquantel; Schistosomiasis; Schistosoma japonicum; Schistosoma haematobium; Schistosoma mansoni; Eating
PubMed: 37498810
DOI: 10.1371/journal.ppat.1011498 -
Nature Communications Nov 2023Regeneration requires mechanisms for producing a wide array of cell types. Neoblasts are stem cells in the planarian Schmidtea mediterranea that undergo fate...
Regeneration requires mechanisms for producing a wide array of cell types. Neoblasts are stem cells in the planarian Schmidtea mediterranea that undergo fate specification to produce over 125 adult cell types. Fate specification in neoblasts can be regulated through expression of fate-specific transcription factors. We utilize multiplexed error-robust fluorescence in situ hybridization (MERFISH) and whole-mount FISH to characterize fate choice distribution of stem cells within planarians. Fate choices are often made distant from target tissues and in a highly intermingled manner, with neighboring neoblasts frequently making divergent fate choices for tissues of different location and function. We propose that pattern formation is driven primarily by the migratory assortment of progenitors from mixed and spatially distributed fate-specified stem cells and that fate choice involves stem-cell intrinsic processes.
Topics: Animals; Planarians; In Situ Hybridization, Fluorescence; Stem Cells; Transcription Factors; Cell Differentiation
PubMed: 37973979
DOI: 10.1038/s41467-023-43267-2 -
Emerging Infectious Diseases Dec 2023Neurocysticercosis is almost exclusively caused by Taenia solium tapeworms. We describe a case of neurocysticercosis in Switzerland caused by infection with Taenia... (Review)
Review
Neurocysticercosis is almost exclusively caused by Taenia solium tapeworms. We describe a case of neurocysticercosis in Switzerland caused by infection with Taenia martis, the marten tapeworm, and review all 5 published cases of human infection with the marten tapeworm. In epidemiologically nonplausible cases of neurocysticercosis, zoonotic spillover infections should be suspected.
Topics: Animals; Humans; Mustelidae; Neurocysticercosis; Switzerland; Taenia; Taenia solium
PubMed: 37987597
DOI: 10.3201/eid2912.230697