Specific fatty acids regulate lipid metabolism and innate immune via the PPAR-CPT1/NF-κB pathway in Hyriopsis cumingii

Copy number variation landscape in the Hyriopsis cumingii genome: Insights into the genetic basis of biomineralization and shell color phenotypic diversity

Nano zerovalent iron (nZVI) faces challenges of agglomeration, oxidation, and biotoxicity in environmental remediation. To address these issues, we synthesized biochar-supported sulfur-functionalized nZVI (BC-S-nZVI) and evaluated its performance in the simultaneous removal of Cr(VI) and acid red 73 (AR73), with exploration of the mechanisms and assessment of the ecotoxicity. The FeSx layer on BC-S-nZVI not only alleviated nZVI agglomeration and oxidation but also provided extra active sites, thus boosting the reactivity. BC-S-nZVI achieved high removal efficiencies of 99.9% for Cr(VI) and 96.9% for AR73 within 300 min with maximum adsorption capacities of 87.3 and 63.7 mg/g, respectively. The adsorption process followed Langmuir and pseudo-second-order models, indicative of monolayer chemisorption. Furthermore, BC-S-nZVI exhibited robust practicality, effectively decontaminating diverse natural water samples and maintaining high efficiency during continuous column operation for 432 h. Ecotoxicity assessments revealed that the BC-S-nZVI composite significantly reduced biotoxicity toward aquatic organisms (e.g., Hyriopsis cumingii) and relieved the inhibitory impact of Cr(VI) and AR73 on soil microorganisms. These findings highlight BC-S-nZVI as a promising, ecofriendly adsorbent for simultaneous remediation of heavy metals and organic pollutants from wastewater and groundwater.

Background: Hyriopsis cumingii polysaccharide (HCP) has been demonstrated to exhibit various biological activities. Our current research aimed to evaluate the protective effect of HCP on the osteoarthritis (OA) model mice. Methods: The therapeutic effect of HCP on OA was investigated by injecting monosodium iodoacetate into a mouse model of knee OA. The analgesic effect was assessed through behavioral analysis. The levels of serum antioxidant substances, including superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT), as well as the levels of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) in articular cartilage, were measured by using enzyme-linked immunosorbent assay. The tissue morphology of articular cartilage was examined using hematoxylin–eosin and safranin O-fast green staining. Microcomputed tomography scans were employed to analyze the microstructure. Additionally, immunohistochemistry was utilized to detect the expression of type II collagen (COL2), matrix metalloproteinase (MMP)13, MMP3, IL-6, nuclear factor-kappa B (NF-κB), and TNF-α proteins in the articular cartilage. Additionally, the impact of HCP on gut microbiota (GM) was assessed through high-throughput fecal 16S ribosomal RNA sequencing. Results: The HCP significantly improved the gait of the mice; increased the levels of serum SOD, GSH-Px, and CAT; and reduced TNF-α and IL-6 in cartilage tissue. The surface of the articular cartilage appeared flat. Subchondral bone destruction was inhibited, and the bone volume fraction was significantly increased. The expression of COL2 was elevated, whereas the expressions of MMP13, MMP3, NF-κB, IL-6, and TNF-α were significantly decreased. HCP can also regulate the diversity of GM, increase the abundance of Firmicutes of GM, and significantly reduce the abundance of Bacteroidetes and Proteobacteria. The gram-negative and pathogenic phenotypes were downregulated in the low-, medium-, and high-dose HCP groups. Conclusions: HCP increases the levels of the body’s antioxidant factors, improves the morphology of cartilage tissue, and optimizes the microstructure of subchondral bone, thereby inhibiting the progression of OA. Therapeutic efficacy HCP may be associated with the regulation of GM.

The nacre protein Hcperlucin provides antibacterial defense following Aeromonas hydrophila infection and crystal morphological modification during shell biomineralization in Hyriopsis cumingii.

Machine vision-based %PP trait drives GWAS of inner shell color in Hyriopsis cumingii

Response of organic matter decomposition and nitrogen transformation in surface sediment to Hyriopsis cumingii bioturbation

Hyriopsis cumingii is an important economic freshwater shellfish in China and there is a need to understand changes in the microbial community structure resulting in multidimensional quality degradation when the fish is stored at different temperatures. This study integrated 16S rRNA full-length sequencing with multidimensional quality indicators to investigate the temperature-regulated bacterial community shifts and quality deterioration mechanisms in stored H. cumingii meat. The results showed that bacterial richness (Chao1 index) decreased progressively with both refrigerated (4°C) and room-temperature (25°C) storage. Community composition underwent significant restructuring, with Bacteroidota decreasing at 25°C while Bacillota increased compared to 4°C storage. Additionally, the refrigerated group showed enrichment of Delftia turuhatensis and Chryseobacterium indologenes compared to the room-temperature storage group. Temperature significantly restructured bacterial communities, with notably higher pathogenic bacteria under refrigeration and spoilage bacteria dominance at room temperature. Metagenomic functional profiling revealed temperature-driven metabolic pathway divergence, indicating distinct spoilage mechanism. Predictable quality changes in H. cumingii correlated with temperature-imposed microbial composition.

Microplastics (MPs) are becoming ubiquitous, and their environmental fate is becoming an issue concern. MPs can adsorb antibiotics to coexist and accumulate in the aquatic environment in the form of complexes, resulting in unforeseeable adverse consequences. Herein, we investigated the genotoxic effects of coexist of polypropylene (PP) microplastic and two antibiotics of sulfamethoxazole (SMX) and oxytetracycline (OTC) at environmental concentrations on gill and gastrointestinal tract (GIT) cells of freshwater pearl mussel Hyriopsis cumingii. Results showed that coexist of PP and antibiotics SMX and OTC at environmental concentrations can cause the DNA damage (5.0 – 8.7% in gill and 4.5 7.9 % in GIT) and micronucleus (10.8 – 20.9 ‰ in gill and 11.9 – 18.6 ‰ in GIT) for H. cumingii. By principal component analysis, we found that there was a strong relationship between microplastic accumulation in the GIT and biomarkers, including DNA damage and micronucleus, for H. cumingii co-exposed to PP microplatics in combination with only OTC antibiotic. Meanwhile, only a strong correlation was detected between microplatic accumulation in gill or GIT and DNA damage in those tisues, when H. cumingii was exposed to mixing anibiotics OTC and SMX along with PP microplastic. Our study contributed to improve the understanding of the adverse genetic impacts of coexistance of PP microplastics and antibiotics (SMX and OTC) in the environment as well as to provided essential information for ecological risk assessment of MPs and antibiotics pollution.

The MIL-101(Cr), a category of MOFs characterized by a notably high specific surface area and well-developed porosity, is extensively employed in removing pollutants from water owing to the material has good stability and adsorption capacity. The sulfidation process markedly improves the performance of nano zerovalent iron, yielding a more effective reducing agent termed S-nZVI. It faces the actual application limitations due to nanoparticle agglomeration. This study prepared composite material (M-S-Fe) by incorporating S-nZVI into the matrix of MIL-101(Cr) via an in situ approach. The results indicated a notable synergy of the two components. This made the composite material highly efficient in eliminating U(VI) at an optimum mass ratio of 1.2:1 and an S/Fe mole ratio of 1:80. Microscopic characterization confirmed an good dispersion of S-nZVI load in MIL-101(Cr) and effectively reducing agglomeration. Batch experiments showed that U(VI) was effectively eliminated using M-S-Fe at pH 6.0 under aerobic conditions, exhibiting a maximum adsorption capacity of 746.3 mg/g. The kinetic data were best fitted by the pseudo-second-order model, while the equilibrium data were well described by the Langmuir isotherm, collectively suggesting a chemisorption mechanism limited to a monolayer coverage. The material maintained over 76% removal efficiency for U(VI) after six reuse cycles, demonstrating excellent reusability. Notably, the material demonstrated significant potential for uranium extraction from seawater, achieving a high removal capacity of 93.4% for U(VI) at an initial concentration of 50 mg/L in simulated seawater. The removal of U(VI) occurred via the synergistic mechanisms of adsorption, reduction, and coprecipitation, as demonstrated by experimental results and XPS analysis. Additionally, M-S-Fe exhibited low toxicity to Hyriopsis cumingii, suggesting its potential as an efficient composite material for uranium elimination in wastewater and seawater.

Mollusk shell formation is a delicate and comprehensive physiological process that relies on the precise deposition of crystals under the control of shell matrix proteins. However, the underlying protective mechanisms governing this process remain largely unknown. Herein, a novel shell matrix protein gene was identified from the freshwater mussel, Hyriopsis cumingii. The predicted protein is characterized by a high glycine content and two Kunitz-type SPI domains, designated as HcGrKuSPI. The HcGrKuSPI gene was highly expressed in the outer epithelial of the mantle edge and mantle pallial. Immunostaining in situ analysis revealed the presence of HcGrKuSPI in the thick inter-prism matrix of the prismatic layer and the organic membrane of the nacreous layer. The expression of HcGrKuSPI in the pearl sac significantly increased during the ordered deposition of pearl nacre tablets. The resultant recombinant protein, SUMO-HcGrKuSPI, exhibited a strong affinity for aragonite and calcite and was involved in the morphological modification of calcite crystals in vitro. These results indicate that HcGrKuSPI is involved in organic framework construction and crystal morphological modification during the prismatic and nacreous layers formation. Furthermore, the expression of HcGrKuSPI in the mantle significantly increased following bacterial infection within the extrapallial fluid, and SUMO-HcGrKuSPI exhibited a strong inhibitory effect against bacterial growth and trypsin activity. Antibody injection in vivo led to severe damage to the thick inter-column framework of the prismatic layer and morphological deformities of nacre tablets. These findings indicate that HcGrKuSPI exhibits excellent protease inhibitory and antibacterial activities, providing a matrix protection system to ensure the smoothness of shell and pearl formation. Overall, these results enhance our understanding of the protective mechanisms involved in mollusk biomineralization.

Pearl protein extracted from freshwater mussels has been shown to inhibit tyrosinase activity. However, the unclear inhibitory mechanism and associated conformational changes limit their practical applications. In this study, peptides from the crude extract of pearl powder are analyzed via liquid chromatography-tandem mass spectrometry (LC-MS/MS). These peptides are subsequently assessed for their tyrosinase inhibitory potential via molecular docking techniques. Notably, experiments reveal that a small-molecule peptide effectively prevents the interaction between 3,4-dihydroxyphenylalanine (L-DOPA) and tyrosinase, impeding the formation of dopaquinone. The peptide GLGGGLAGAGGADGA (95P, 1099.54 Da) shows particular promise, with synthesized 95P inhibiting both the monophenolase and diphenolase activities of tyrosinase, with IC 50 values of 30.97 ± 0.75 μM and 64.62 ± 3.08 μM,respectively. 95P inhibits tyrosinase activity in a mixed competitive and reversible manner. Molecular dynamics simulations suggest that 95P stabilizes 5M8N, impeding structural contraction identified by model number 5M8N. In conclusion, 95P is a powerful and stable tyrosinase inhibitor with the potential to be used as a skin whitening agent in the pharmaceutical field and an anti-browning agent in the food industry.

A novel Toll-like receptor in Hyriopsis cumingii responds to Aeromonas veronii GL1 infection by the MyD88 signaling pathway.

Elucidating the regulatory role of Nrf2 in Beclin1-mediated autophagy in freshwater bivalve Hyriopsis cumingii.

Pearl color serves as the paramount criterion for quality assessment and commercial valuation in the global pearl industry. Freshwater nucleated pearls, which constitute 95% of global production, exhibit striking chromatic diversity. This study deciphers the chromogenic mechanisms of freshwater nucleated cultured pearls in Hyriopsis cumingii from Zhuji, China, through integrated spectroscopic (UV-vis-NIR and Raman), colorimetric (CIELAB), and trace-element (LA-ICP-MS) analyses. We identify polyene compounds as the primary organic chromophores, with C=C bond counts determining core hue: purple (12 C=C bonds), pink (11 C=C bonds), and white/orange (10 C=C bonds). Color expression is further modulated by nacre microstructure; densely aligned aragonite tablets enhance optical interference in purple pearls, whereas irregular tablet arrangements in pink and orange pearls promote diffuse scattering. Crucially, trace elements (Mn, Fe, Cu, Zn) contribute synergistically via metalloporphyrin formation (e.g., Mn-porphyrin in purple variants) and aragonite lattice substitutions. These findings reveal that pearl coloration arises from the interplay of biological factors (organic matrix), physical structure (nacre architecture), and chemical composition (trace elements), providing insights for quality enhancement and sustainable aquaculture practices.

The role of the Steroidogenesis-Associated gene cyp11a in regulating gonadal development in Hyriopsis cumingii.

Fibroblast growth factor binding proteins (FGF-BPs) are involved in bone formation by binding to FGFs and modulating FGF signaling in vertebrates. Herein, a novel shell matrix protein gene, HcN13, was identified from the mussels Hyriopsis cumingii. Sequence analysis indicated that HcN13 belongs to the FGF-BP1 family. Quantitative real-time PCR and in situ hybridization analysis showed that HcN13 is expressed in the dorsal epithelial cells of the mantle center, indicating that HcN13 is a shell nacreous layer matrix protein. The expression of HcN13 in the mantle significantly increased during the regeneration of the prismatic and nacreous layers. Furthermore, the suppression of HcN13 at both the transcriptional and protein levels resulted in the complete destruction of the prisms and nacre tablets in vivo. However, the addition of SUMO-HcN13 did not affect the polymorphism and morphology of the crystals in vitro. These results indicated that HcN13 may serve as a modulator that influences downstream signaling pathways to further regulate shell formation. Additionally, HcN13 was highly expressed in hemocytes during pearl nacre disorder deposition and was also highly expressed in the mantle during pearl nacre order deposition, indicating that HcN13 is essential for pearl biomineralization. This study demonstrates, for the first time, the presence of FGF-BPs in the mollusk shell, highlighting their essential role in biomineralization in invertebrates.

The mechanism of IGF-AKT pathway promoting mantle biomineralization in Hyriopsis cumingii.

Genotype-environment interactions on growth and inner shell color variation in Hyriopsis cumingii cultured in different iron-level substrates

HcCnAα regulates NF-κB signaling in Hyriopsis cumingii by interacting with HcIKK and facilitating IκB phosphorylation.