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Marine Life Science & Technology
Number of Followers: 1  Hybrid journal (It can contain Open Access articles)ISSN (Online) 2662-1746 Published by Springer-Verlag  [2468 journals]
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- Discovery of a potential bladder cancer inhibitor CHNQD-01281 by
regulating EGFR and promoting infiltration of cytotoxic T cells-
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Abstract: Abstract As one of the common malignancies that threaten human life, bladder cancer occurs frequently with a high mortality rate in the world, due to its invasion, recurrence and drug resistance. Natural products from marine microorganisms are becoming the hotspots in discovery of new candidate drug entities, especially in the area of cancer. Brefeldin A (BFA) is a natural Arf-GEFs inhibitor, but due to the low aqueous solubility, strong toxicity, and poor bioavailability, it is urgent to conduct structural optimization research. Herein, a new BFA pyridine acrylate derivative CHNQD-01281 with improved solubility was prepared and found to exert moderate to strong antiproliferative activity on a variety of human cancer cell lines. It was noteworthy that CHNQD-01281 was most sensitive to two bladder cancer cell lines T24 and J82 (IC50 = 0.079 and 0.081 μmol/L) with high selectivity index (SI = 14.68 and 14.32), suggesting a superior safety to BFA. In vivo studies revealed that CHNQD-01281 remarkably suppressed tumor growth in a T24 nude mice xenograft model (TGI = 52.63%) and prolonged the survival time (ILS = 68.16%) in an MB49 allogeneic mouse model via inducing infiltration of cytotoxic T cells. Further mechanism exploration indicated that CHNQD-01281 regulated both EGFR/PI3K/AKT and EGFR/ERK pathways and mediated the chemotactic effect of chemokines on immune effector cells. Overall, CHNQD-01281 may serve as a potential therapeutic agent for bladder cancer through multiple mechanisms.
PubDate: 2024-08-05
DOI: 10.1007/s42995-024-00246-w
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- Community structure and carbon metabolism functions of bacterioplankton in
the Guangdong coastal zone-
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Abstract: Abstract Coastal ecosystems are an important region for biogeochemical cycling, are a hotspot of anthropogenic disturbance and play a crucial role in global carbon cycling through the metabolic activities of bacterioplankton. Bacterioplankton can be broadly classified into two lifestyles: free-living (FL) and particle-attached (PA). However, how coastal bacterioplankton the community structure, co-occurrence networks and carbon metabolic functions with different lifestyles are differentiated is still largely unknown. Understanding these processes is necessary to better determine the contributions of coastal bacterioplankton to carbon cycling. Here, the characteristics of community structure and carbon metabolism function of bacterioplankton with two lifestyles in the coastal areas of Guangdong Province were investigated using amplicon sequencing, metagenomic, and metatranscriptomic techniques. The results show that the main bacterioplankton responsible for carbon metabolism were the Pseudomonadota, Bacteroidota, and Actinomycetota. The microbial community structure, carbon metabolic function, and environmental preferences differ between different lifestyles. FL and PA bacteria exhibited higher carbon fixation and degradation potentials, respectively. A range of environmental factors, such as dissolved oxygen, pH, and temperature, were associated with the community structure and carbon metabolic functions of the bacterioplankton. Human activities, such as nutrient discharge, may affect the distribution of functional genes and enhance the carbon degradation functions of bacterioplankton. In conclusion, this study increased the understanding of the role of microorganisms in regulating carbon export in coastal ecosystems with intense human activity.
PubDate: 2024-07-29
DOI: 10.1007/s42995-024-00245-x
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- The potent osteo-inductive capacity of bioinspired brown seaweed-derived
carbohydrate nanofibrous three-dimensional scaffolds-
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Abstract: Abstract This study aimed to investigate the osteo-inductive capacity of a fucoidan polysaccharide network derived from brown algae on human adipose-derived stem cells (HA-MSCs) for bone regeneration. The physiochemical properties of the scaffold including surface morphology, surface chemistry, hydrophilicity, mechanical stiffness, and porosity were thoroughly characterized. Both in vitro and in vivo measurements implied a superior cell viability, proliferation, adhesion, and osteo-inductive performance of obtained scaffolds compared to using specific osteogenic induction medium with increased irregular growth of calcium crystallites, which mimic the structure of natural bones. That scaffold was highly biocompatible and suitable for cell cultures. Various examinations, such as quantification of mineralization, alkaline phosphatase, gene expression, and immunocytochemical staining of pre-osteocyte and bone markers confirmed that HAD-MSCs differentiate into osteoblasts, even without an osteogenic induction medium. This study provides evidence for the positive relationship and synergistic effects between the physical properties of the decellularized seaweed scaffold and the chemical composition of fucoidan in promoting the osteogenic differentiation of HA-MSCs. Altogether, the natural matrices derived from brown seaweed offers a sustainable, cost-effective, non-toxic bioinspired scaffold and holds promise for future clinical applications in orthopedics.
PubDate: 2024-07-24
DOI: 10.1007/s42995-024-00241-1
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- Molecular mechanism of a coastal cyanobacterium Synechococcus sp. PCC 7002
adapting to changing phosphate concentrations-
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Abstract: Abstract Phosphorus concentration on the surface of seawater varies greatly with different environments, especially in coastal. The molecular mechanism by which cyanobacteria adapt to fluctuating phosphorus bioavailability is still unclear. In this study, transcriptomes and gene knockouts were used to investigate the adaptive molecular mechanism of a model coastal cyanobacterium Synechococcus sp. PCC 7002 during periods of phosphorus starvation and phosphorus recovery (adding sufficient phosphorus after phosphorus starvation). The findings indicated that phosphorus deficiency affected the photosynthesis, ribosome synthesis, and bacterial motility pathways, which recommenced after phosphorus was resupplied. Even more, most of the metabolic pathways of cyanobacteria were enhanced after phosphorus recovery compared to the control which was kept in continuous phosphorus replete conditions. Based on transcriptome, 54 genes potentially related to phosphorus-deficiency adaptation were selected and knocked out individually or in combination. It was found that five mutants showed weak growth phenotype under phosphorus deficiency, indicating the importance of the genes (A0076, A0549-50, A1094, A1320, A1895) in the adaptation of phosphorus deficiency. Three mutants were found to grow better than the wild type under phosphorus deficiency, suggesting that the products of these genes (A0079, A0340, A2284–86) might influence the adaptation to phosphorus deficiency. Bioinformatics analysis revealed that cyanobacteria exposed to highly fluctuating phosphorus concentrations have more sophisticated phosphorus acquisition strategies. These results elucidated that Synechococcus sp. PCC 7002 have variable phosphorus response mechanisms to adapt to fluctuating phosphorus concentration, providing a novel perspective of how cyanobacteria may respond to the complex and dynamic environments.
PubDate: 2024-07-22
DOI: 10.1007/s42995-024-00244-y
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- Exogenous indole modulates several CpxRA-mediated virulence-related
parameters of Edwardsiella piscicida in vitro-
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Abstract: Abstract Indole signaling has been regarded as a promising target to control aquatic diseases. However, the relationship between exogenous indole and the virulence of Edwardsiella piscicida is obscure. E. piscicida is a facultative intracellular pathogen, and has been a model strain in aquaculture. In this study, we investigated the effect of exogenous indole on stress resistance and virulence of E. piscicida in the presence of and absence of endogenous indole (WT and ΔtnaA, respectively). Our results showed that exogenous indole reduced the resistance of WT against strong acidic stress, but enhanced that of ΔtnaA. Also, we found that exogenous indole abated viability of E. piscicida at high temperature, repressed bacterial biofilm formation, impaired bacterial envelope integrity, and weakened bacterial proliferation in macrophages, irrespective of the presence or absence of endogenous indole. These virulence-related phenotypes caused by exogenous indole are reasonably explained by the observation that exogenous indole downregulated the expressions of CpxRA and its target YccA via being responded by CpxA. The effects of exogenous indole on strong acid resistance are partially achieved by changing the expression of GadD, the key functional enzyme of acid resistance system (AR2). We believe that this is the first report about the impact of exogenous indole on strong acid stress and membrane integrity of pathogenic bacteria. Also, we reveal the likely mechanism by which exogenous indole regulates the expressions of virulence-related genes. These findings provide a new understanding on pathogenesis of E. piscicida and contribute to the prevention and control strategies of edwardsiellosis.
PubDate: 2024-07-10
DOI: 10.1007/s42995-024-00238-w
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- Pufferfish gasdermin Ea is a significant player in the defense against
bacterial pathogens-
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Abstract: Abstract Gasdermins (GSDMs) are proteins cleaved by caspase (CASP) to trigger pyroptosis. In teleosts, pyroptosis is mediated by gasdermin E (GSDME). The Pufferfish, Takifugu rubripes, possesses two GSDME orthologs: named TrGSDMEa and TrGSDMEb. TrGSDMEa is cleaved by CASP3/7 to liberate the N-terminal (NT) domain that can trigger pyroptosis in mammalian cells. However, the biological function of TrGSDMEa in pufferfish is unknown, and TrGSDMEb is poorly studied. We found that TrGSDMEb was cleaved by CASP1/3/6/7/8, but the resulting NT domain, despite its similarity to TrGSDMEa-NT domain in sequence and structure, failed to induce pyroptosis. TrGSDMEa and TrGSDMEb exhibited similar expression patterns in pufferfish under normal physiological conditions but were up- and downregulated, respectively, in expression during Vibrio harveyi and Edwardsiella tarda infection. Bacterial infection induced the activation of TrGSDMEa and CASP3/7 in pufferfish cells, resulting in pyroptosis accompanied with IL-1β production and maturation. Inhibition of TrGSDMEa-mediated pyroptosis via TrCASP3/7 reduced the death of pufferfish cells and augmented bacterial dissemination in fish tissues. Structure-oriented mutagenesis identified 16 conserved residues in teleost GSDMEa that were required for the pore formation or auto-inhibition of GSDMEa. This study illustrates the role of GSDMEa-mediated pyroptosis in teleost defense against bacterial pathogens and provides new insights into the structure-based function of vertebrate GSDME.
PubDate: 2024-06-28
DOI: 10.1007/s42995-024-00237-x
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- Exploring the biogeography, morphology, and phylogeny of the
condylostomatid ciliates (Alveolata, Ciliophora, Heterotrichea), with
establishment of four new Condylostoma species and a revision including
redescriptions of five species found in China-
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Abstract: Abstract Species of the ciliate class Heterotrichea Stein, 1859 are a cosmopolitan group of unicellular eukaryotic microorganisms, many of which have been widely used as models in various fields of research such as regenerative biology, functional ecology, environmental toxicology, and symbiotic behavior. However, species identification in the heterotrich family Condylostomatidae, especially the most species-rich and type genus Condylostoma Bory de Saint-Vincent, 1824, remains challenging due to incomplete original descriptions, few reliable distinguishing characters, and overlapping features between different species. This study presents an updated revision of Condylostoma and its related genus Condylostomides da Silva Neto, 1994 based on descriptions of five species, including nine populations collected from China, using both morphological and molecular methods. The main findings are as follows: (1) 43 nominal species and about 130 populations are reviewed, resulting in the recognition of 30 valid species of Condylostoma and eight valid species of Condylostomides; (2) keys, synonyms, biogeographic distributions and amended/improved diagnoses of all valid species are provided; (3) based on the available data, four new Condylostoma species (C. marinum sp. nov., C. petzi sp. nov., C. villeneuvei sp. nov., and C. microstomum sp. nov.), one new combination (Condylostomides minimus (Dragesco, 1954) comb. nov. & nom. corr.), and two corrected names (Condylostoma ancestrale Villeneuve-Brachon, 1940 nom. corr. and Condylostomides nigrus (Dragesco, 1960) nom. corr.) are suggested; (4) cryptic species are detected and proposed for the first time to form the Condylostoma curvum species complex; (5) three highly confusing Condylostoma species, C. kris, C. spatiosum, and C. minutum, are redefined for the first time based on modern taxonomic methods; (6) a ‘flagship’ species, Condylostomides coeruleus, is recorded for the first time from the continent of Asia, substantially expanding its biogeography; (7) ciliature adjacent to the distal end of the paroral membrane within the family Condylostomatidae is uniformly defined as frontal membranelles and is classified into three patterns according to the arrangement of kinetosomes, which serve as important key features.
PubDate: 2024-06-26
DOI: 10.1007/s42995-024-00223-3
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- Matrine-loaded self-adhesive swelling microneedle for inflammation
regulation to improve eczema treatment-
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Abstract: Abstract Eczema is a common chronic dermatological disease. Conventional treatments exhibit limited efficacy due to fast drug release resulting in short-term relief. Development of a new treatment strategy that enables sustained drug release and long-term maintenance on the skin surface is necessary. A self-adhesive swelling microneedle patch (SDSMNs) was designed and constructed using a two-step casting method. The adhesive substrate was prepared by blending gelatin and dopamine via oxidation of NaIO4, so it could adhere onto the skin surface as well as withstand repeated bending movement without detachment. The swelling needles were fabricated using polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP), which could swell by absorbing interstitial fluid and release the drug in a controlled manner. SDSMNs also showed desirable antibacterial activities toward E. coli and S. aureus. The adhesive microneedles loaded with matrine (MAT-SDSMNs), an anti-inflammatory Chinese medicine, dramatically relieved eczema symptoms through IL-17 mediated inflammation responses. The use of MAT-SDSMNs significantly decreased the infiltration of inflammation cells and level of inflammatory cytokines, reduced the skin thickness, and increased collagen deposition fraction compared with conventional ointment or subcutaneous injection. The results suggested that MAT-SDSMNs can improve eczema treatment by regulating the local inflammatory microenvironment, providing a simple, self-administered sustainable strategy for eczema treatment.
PubDate: 2024-06-26
DOI: 10.1007/s42995-024-00235-z
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- Environmental dispersal and host priority effect alternatively dominate
intestinal microbiota succession of cultured shrimp along with host
development-
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Abstract: Abstract Given the importance of the intestinal microbiota in life-long health, increasing attention has been paid to ecological mechanisms that govern microbial succession. Both environmental dispersal and host priority effect play important roles in intestinal microbiota succession of aquatic animals, but their relative importance is unknown. Here, we explore the intestinal microbiota succession and assembly of Litopenaeus vannamei across larvae, postlarvae, juvenile, and preadult stages. We aimed to clarify the relative contributions between environmental dispersal and host priority effect on intestinal microbiota succession. We found that both α- and β-diversity of the intestinal microbiota changed dynamically along with host development. In particular, the intestinal microbiota assemblies were dominated by stochastic processes, except with the larvae stage. The succession of shrimp intestinal microbiota was clearly influenced by internal communities in the intestines of larvae, as well as the external communities in water and sediment. Importantly, the impact of environmental dispersal on the intestinal microbiota succession outweighed the host priority effect during the larvae and postlarvae stages. However, this situation was largely reversed during the juvenile and preadult stages. The possible reason is that, during the larvae and postlarvae stages, shrimp mainly feed on plankton from the environment, and their digestive system remains underdeveloped, the host recruits numerous microbes from the environment and selects specific microbes to aid digestion and nutrient absorption. These findings enhance our understanding of alternate effects of environmental and host factors on the intestinal microbiota succession of aquatic animals and provide a foundation for developing microecological management strategies in shrimp culture.
PubDate: 2024-06-14
DOI: 10.1007/s42995-024-00236-y
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- Skeletal microstructures of cheilostome bryozoans (phylum Bryozoa, class
Gymnolaemata): crystallography and secretion patterns-
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Abstract: Abstract Gymnolaemata bryozoans produce CaCO3 skeletons of either calcite, aragonite, or both. Despite extensive research, their crystallography and biomineralization patterns remain unclear. We present a detailed study of the microstructures, mineralogy, and crystallography of eight extant cheilostome species using scanning electron microscopy, electron backscatter diffraction, atomic force microscopy, and micro-computed tomography. We distinguished five basic microstructures, three calcitic (tabular, irregularly platy, and granular), and two aragonitic (granular-platy and fibrous). The calcitic microstructures consist of crystal aggregates that transition from tabular or irregularly platy to granular assemblies. Fibrous aragonite consists of fibers arranged into spherulites. In all cases, the crystallographic textures are axial, and stronger in aragonite than in calcite, with the c-axis as the fiber axis. We reconstruct the biomineralization sequence in the different species by considering the distribution and morphology of the growth fronts of crystals and the location of the secretory epithelium. In bimineralic species, calcite formation always predates aragonite formation. In interior compound walls, growth proceeds from the cuticle toward the zooecium interior. We conclude that, with the exception of tabular calcite, biomineralization is remote and occurs within a relatively wide extrapallial space, which is consistent with the inorganic-like appearance of the microstructures. This biomineralization mode is rare among invertebrates.
PubDate: 2024-06-07
DOI: 10.1007/s42995-024-00233-1
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- Examination of wnt signaling mediated melanin transport and shell color
formation in Pacific oyster (Crassostrea gigas)-
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Abstract: Abstract Mollusca exhibit remarkable diversity in shell coloration, attributed to the presence of melanin, a widely distributed pigment with various essential roles, such as mechanical strengthening, antioxidation and thermoregulation. However, the regulatory network governing melanogenesis and melanin transport in molluscs remains poorly understood. In this study, we conducted a systematic analysis of melanin distribution and transport in the Pacific oyster, utilizing light microscopy and high-resolution transmission electron microscopy. In addition, we characterized CgWnt1 and CgWnt2b-a in Crassostrea gigas, and analyzed Wnt signaling in melanocyte formation. Expression analysis revealed that these genes were predominantly expressed in the mantle of black-shelled individuals, particularly in the outer fold of the mantle. Furthermore, we employed RNA interference and inhibitors to specifically inhibit Wnt signaling in both in vivo and in vitro. The results revealed impaired melanogenesis and diminished tyrosinase activity upon Wnt signaling inhibition. These findings suggest the crucial role of Wnt ligands and downstream factors in melanogenesis. In summary, our study provides valuable insights into the regulatory mechanism of shell pigmentation in C. gigas. By demonstrating the promotion of melanogenesis through Wnt signaling modulation, we contribute to a better understanding of the complex processes underlying molluscan melanin production and shell coloration.
PubDate: 2024-06-06
DOI: 10.1007/s42995-024-00221-5
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- Impacts of climate change on mangrove subsistence fisheries: a global
review-
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Abstract: Abstract Climate change will impact coastal ecosystems, threatening subsistence fisheries including those in mangrove forests. Despite their global contributions and roles in nutrition and cultural identity, mangrove subsistence fisheries are poorly studied. Here, we offer a foundation for improving the management of mangrove subsistence fisheries to deal with the impending effects of climate change. This multidisciplinary review—drawing on organismal biology, ecology, fisheries, and social science—focuses on the climate impacts relevant to mangrove ecosystems: heat waves, low-category, and high-category typhoons. First, we provide an overview of the mangroves, their harvestable stocks (fish, crustaceans, molluscs), and the fishers, offering an understanding of how they may be affected by relevant environmental variables; i.e., shifts in temperature, salinity, oxygen, flooding, and sediments. Then, we examine the potential effects of climate change on mangrove stocks and fishers, indicating the scope of impending changes. By combining the above information, we develop a simple model that forecasts the number of “fishing-days” lost by fishers due to climate change over the next decade (between 11 and 21 days will be lost per year per fisher). This indicates which aspects of climate change will have the greatest impacts on stocks and fishers. We found that high-category typhoons had more impacts than heat waves, which in turn had a greater impact than low-category typhoons). Finally, recognising gaps in our knowledge and understanding, we offer recommendations for approaches for future work to improve our predictions.
PubDate: 2024-06-05
DOI: 10.1007/s42995-024-00231-3
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- Tbx21 gene and its association with resistance against viral nervous
necrosis (VNN) in Asian seabass, Lates calcarifer-
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Abstract: Abstract Viral nervous necrosis (VNN) caused by a betanodavirus (NNV) is one of the major diseases in Asian seabass (Lates calcarifer) hatcheries. Our previous studies showed that the tbx21 gene was in a QTL for NNV resistance in linkage group 23 in Asian seabass. The expression of this gene was changed in tissues of Asian seabass challenged with NNV. However, the role of tbx21 in NNV resistance remains largely unknown. In this study, tbx21 of Asian seabass was characterized. This gene consists of an ORF of 1866 bp, a 5′ UTR of 357 bp, and a 3′ UTR of 4674 bp. The TBX21 protein showed substantial amino acid similarity (70–96%) with other fish but exhibited lower identity (47–52%) with mammals. One SNP identified in the first intron was significantly associated with NNV resistance. In healthy fish, tbx21 was expressed in all tissues examined, and was highly expressed in the kidney and liver. The expression of tbx21 increased in the eye, gills, heart, kidney and gut, but decreased in the brain and spleen at five days after NNV challenge. Overexpression of tbx21 reduced the replication of NNV, whereas knockdown increased viral expression and virus titers. These results suggest that tbx21 plays a key role in NNV resistance. The SNP in this gene could be used as a marker to facilitate marker-assisted selection for NNV resistance. Further investigation of polymorphisms in the 5’ and 3’ UTRs of tbx21 may provide additional insights into the gene's role in NNV resistance.
PubDate: 2024-05-31
DOI: 10.1007/s42995-024-00234-0
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- Correction: Spontaneous mutations and mutational responses to penicillin
treatment in the bacterial pathogen Streptococcus pneumoniae D39-
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PubDate: 2024-05-22
DOI: 10.1007/s42995-024-00232-2
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- Findings on three endocommensal scuticociliates (Protista, Ciliophora)
from freshwater mollusks, including their morphology and molecular
phylogeny with descriptions of two new species-
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Abstract: Abstract Species of the ciliate genera Myxophyllum and Conchophthirus are found as endocommensals of terrestrial and freshwater mollusks, respectively. So far, there have been few studies of these genera and morphological data for most members are often incomplete. In the present work, two new species, Myxophyllum weishanense sp. nov. and Conchophthirus paracurtus sp. nov., and a known species, Conchophthirus lamellidens, were isolated from hosts in Lake Weishan Wetland, China. Taxonomic studies indicate that M. weishanense sp. nov. can be recognized mainly by the combination of about 60 somatic kineties on both ventral and dorsal sides and the presence of caudal cilia. Conchophthirus paracurtus sp. nov. differs from congeners in its body shape and size, having a glabrous area on the posterior right side, and having fewer somatic kineties. In addition, differences in their ITS2 (Internally Transcribed Spacer 2) secondary structures support the discrimination of the two new species from their highly similar congeners. An improved diagnosis for the poorly known species, C. lamellidens is also provided. Phylogenetic analyses reveal that members of the genus Myxophyllum belong to a fully supported clade that is sister to a large, poorly supported clade consisting of Hemispeiridae, Ancistridae, and several lineages of the nonmonophyletic Cyclidiidae. The Myxophyllum clade also includes Protophyra ovicola JQ956552, a possible misidentification. Sequences of the two new Conchophthirus species cluster with other congeners in a fully supported clade that is unrelated to either the ‘typical’ thigmotrichs or to pleuronematids, thus conflicting with the traditional classification, and may represent an orphan scuticociliate lineage.
PubDate: 2024-05-21
DOI: 10.1007/s42995-024-00230-4
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- Context-dependent antioxidant defense system (ADS)-based stress memory in
response to recurrent environmental challenges in congeneric invasive
species-
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Abstract: Abstract Marine ecosystems are facing escalating environmental fluctuations owing to climate change and human activities, imposing pressures on marine species. To withstand recurring environmental challenges, marine organisms, especially benthic species lacking behavioral choices to select optimal habitats, have to utilize well-established strategies such as the antioxidant defense system (ADS) to ensure their survival. Therefore, understanding of the mechanisms governing the ADS-based response is essential for gaining insights into adaptive strategies for managing environmental challenges. Here we conducted a comparative analysis of the physiological and transcriptional responses based on the ADS during two rounds of 'hypersalinity-recovery' challenges in two model congeneric invasive ascidians, Ciona robusta and C. savignyi. Our results demonstrated that C. savignyi exhibited higher tolerance and resistance to salinity stresses at the physiological level, while C. robusta demonstrated heightened responses at the transcriptional level. We observed distinct transcriptional responses, particularly in the utilization of two superoxide dismutase (SOD) isoforms. Both Ciona species developed physiological stress memory with elevated total SOD (T-SOD) and glutathione (GSH) responses, while only C. robusta demonstrated transcriptional stress memory. The regulatory distinctions within the Nrf2-Keap1 signalling pathway likely explain the formation disparity of transcriptional stress memory between both Ciona species. These findings support the 'context-dependent stress memory hypothesis', emphasizing the emergence of species-specific stress memory at diverse regulatory levels in response to recurrent environmental challenges. Our results enhance our understanding of the mechanisms of environmental challenge management in marine species, particularly those related to the ADS.
PubDate: 2024-05-08
DOI: 10.1007/s42995-024-00228-y
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- Correction: Incorporating mesopelagic fish into the evaluation of marine
protected areas under climate change scenarios-
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PubDate: 2024-05-01
DOI: 10.1007/s42995-023-00193-y
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- Mucosal immune responses to Ichthyophthirius multifiliis in the ocular
mucosa of rainbow trout (Oncorhynchus mykiss, Walbaum), an ancient teleost
fish-
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Abstract: Abstract The eye, as a specialized visual organ, is directly exposed to the external environment, and, therefore, it faces constant challenges from external pathogenic organisms and toxins. In the ocular mucosa (OM) of mammals, mucosal-associated lymphoid tissues (MALTs) constitute the primary line of defense. However, the immune defense role of the OM remains unknown in aquatic vertebrates. To gain insights into the immune processes within the OM of teleost fish, we developed an infection model of rainbow trout (Oncorhynchus mykiss) OM using a parasite, Ichthyophthirius multifiliis (Ich). Immunofluorescence, qPCR, and H&E staining revealed that Ich successfully infiltrates the OM of rainbow trout, leading to pathological structural changes, as evidenced by A&B staining. Importantly, the qPCR results indicate an up-regulation of immune-related genes following Ich infection in the OM. Moreover, transcriptome analyses were conducted to detect immune responses and impairments in eye function within the OM of rainbow trout with Ich infection. The results of the transcriptome analysis that Ich infection can cause an extensive immune response in the OM, ultimately affecting ocular function. To the best of our knowledge, our findings represent for the first time that the teleost OM could act as an invasion site for parasites and trigger a strong mucosal immune response to parasitic infection.
PubDate: 2024-05-01
DOI: 10.1007/s42995-023-00199-6
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- Spontaneous mutations and mutational responses to penicillin treatment in
the bacterial pathogen Streptococcus pneumoniae D39-
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Abstract: Abstract Bacteria with functional DNA repair systems are expected to have low mutation rates due to strong natural selection for genomic stability. However, our study of the wild-type Streptococcus pneumoniae D39, a pathogen responsible for many common diseases, revealed a high spontaneous mutation rate of 0.02 per genome per cell division in mutation-accumulation (MA) lines. This rate is orders of magnitude higher than that of other non-mutator bacteria and is characterized by a high mutation bias in the A/T direction. The high mutation rate may have resulted from a reduction in the overall efficiency of selection, conferred by the tiny effective population size in nature. In line with this, S. pneumoniae D39 also exhibited the lowest DNA mismatch-repair (MMR) efficiency among bacteria. Treatment with the antibiotic penicillin did not elevate the mutation rate, as penicillin did not induce DNA damage and S. pneumoniae lacks a stress response pathway. Our findings suggested that the MA results are applicable to within-host scenarios and provide insights into pathogen evolution.
PubDate: 2024-04-16
DOI: 10.1007/s42995-024-00220-6
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- Role of marine natural products in the development of antiviral agents
against SARS-CoV-2: potential and prospects-
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Abstract: Abstract A novel coronavirus, known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has surfaced and caused global concern owing to its ferocity. SARS-CoV-2 is the causative agent of coronavirus disease 2019; however, it was only discovered at the end of the year and was considered a pandemic by the World Health Organization. Therefore, the development of novel potent inhibitors against SARS-CoV-2 and future outbreaks is urgently required. Numerous naturally occurring bioactive substances have been studied in the clinical setting for diverse disorders. The intricate infection and replication mechanism of SARS-CoV-2 offers diverse therapeutic drug targets for developing antiviral medicines by employing natural products that are safer than synthetic compounds. Marine natural products (MNPs) have received increased attention in the development of novel drugs owing to their high diversity and availability. Therefore, this review article investigates the infection and replication mechanisms, including the function of the SARS-CoV-2 genome and structure. Furthermore, we highlighted anti-SARS-CoV-2 therapeutic intervention efforts utilizing MNPs and predicted SARS-CoV-2 inhibitor design.
PubDate: 2024-02-21
DOI: 10.1007/s42995-023-00215-9
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