Significant Changes In Expression Research Articles

Selective Estrogen Receptor Modulators’ (SERMs) Influence on TET3 Expression in Breast Cancer Cell Lines with Distinct Biological Subtypes

Tamoxifen, a selective estrogen receptor modulator (SERM), exhibits dual agonist or antagonist effects contingent upon its binding to either G-protein-coupled estrogen receptor (GPER) or estrogen nuclear receptor (ESR). Estrogen signaling plays a pivotal role in initiating epigenetic alterations and regulating estrogen-responsive genes in breast cancer. Employing three distinct breast cancer cell lines—MCF-7 (ESR+; GPER+), MDA-MB-231 (ESR−; GPER−), and SkBr3 (ESR−; GPER+)—this study subjected them to treatment with two tamoxifen derivatives: 4-hydroxytamoxifen (4-HT) and endoxifen (Endox). Through 2D high-performance liquid chromatography with tandem mass spectrometry detection (HPLC-MS/MS), varying levels of 5-methylcytosine (5-mC) were found, with MCF-7 displaying the highest levels. Furthermore, TET3 mRNA expression levels varied among the cell lines, with MCF-7 exhibiting the lowest expression. Notably, treatment with 4-HT induced significant changes in TET3 expression across all cell lines, with the most pronounced increase seen in MCF-7 and the least in MDA-MB-231. These findings underscore the influence of tamoxifen derivatives on DNA methylation patterns, particularly through modulating TET3 expression, which appears to be contingent on the presence of estrogen receptors. This study highlights the potential of targeting epigenetic modifications for personalized anti-cancer therapy, offering a novel avenue to improve treatment outcomes.

Developing an RNA Signature for Radiation Injury Using a Human Liver-on-a-Chip Model.

Radiation exposure in a therapeutic setting or during a mass casualty event requires improved medical triaging, where the time to delivery and quantity of medical countermeasures are critical to survival. Radiation-induced liver injury (RILI) and fibrosis can lead to death, but clinical symptoms manifest late in disease pathogenesis and there is no simple diagnostic test to determine RILI. Because animal models do not completely recapitulate clinical symptoms, we used a human liver-on-a-chip model to identify biomarkers of RILI. The goals of this study were: 1. to establish a microfluidic liver-on-a-chip device as a physiologically relevant model for studying radiation-induced tissue damage; and 2. to determine acute changes in RNA expression and biological pathway regulation that identify potential biomarkers and mechanisms of RILI. To model functional human liver tissue, we used the Emulate organ-on-a-chip system to establish a co-culture of human liver sinusoidal endothelial cells (LSECs) and hepatocytes. The chips were subject to 0 Gy (sham), 1 Gy, 4 Gy, or 10 Gy irradiation and cells were collected at 6 h, 24 h, or 7 days postirradiation for RNA isolation. To identify significant expression changes in messenger RNA (mRNA) and long non-coding RNA (lncRNA), we performed RNA sequencing (RNASeq) to conduct whole transcriptome analysis. We found distinct differences in expression patterns by time, dose, and cell type, with higher doses of radiation resulting in the most pronounced expression changes, as anticipated. Ingenuity Pathway Analysis indicated significant inhibition of the cell viability pathway 24 h after 10 Gy exposure in LSECs but activation of this pathway in hepatocytes, highlighting differences between cell types despite receiving the same radiation dose. Overall, hepatocytes showed fewer gene expression changes in response to radiation, with only 3 statistically significant differentially expressed genes at 7 days: APOBEC3H, PTCHD4, and GDNF. We further highlight lncRNA of interest including DINO and PURPL in hepatocytes and TMPO-AS1 and PRC-AS1 in LSECs, identifying potential biomarkers of RILI. We demonstrated the potential utility of a human liver-on-a-chip model with primary cells to model organ-specific radiation injury, establishing a model for radiation medical countermeasure development and further biomarker validation. Furthermore, we identified biomarkers that differentiate radiation dose and defined cell-specific targets for potential radiation mitigation therapies.

Tissue distribution and expression dynamics of trefoil factor genes in the hydroid Hydractinia symbiolongicarpus

Proteins of the trefoil factor family (TFF) participate in mucosal repair and are formed by single or tandemly repeated trefoil domains. TFFs have been extensively studied in mammals and amphibians, but they have not been functionally characterized in other animals. Here we report the identification of two genes expressed in the hydroid Hydractinia symbiolongicarpus, predicted to encode trefoil domain-containing peptides, one with four trefoil domains in tandem and the other one with a trefoil domain flanked by two ShKT domains. Differential expression analyses by qPCR after an immune challenge and an induced mechanical damage, reveal that the former gene (hysyTFF) had no significant changes in expression after the inductions. However, the latter (hysyTFF-like) was overexpressed after three hours post immune challenge and was downregulated after the first hour post epithelial damage. Immunoblot analyses using specific Ig Y antibodies revealed that hysyTFF is secreted as a high molecular weight complex. Finally, whole mount immunofluorescence assays showed that hysyTFF was predominantly expressed in the endoderm of stolons and polyps, and sparsely in the ectoderm of both polyps and larvae. Thus, tissue distribution and expression dynamics of trefoil factor genes in H. symbiolongicarpus suggest that hysyTFF is an ancient mechanism of epithelial restitution, and the newly reported TFF-like might act as an immune effector gene, perhaps encoding an antibacterial peptide.

Genome and Transcriptome Analysis of NF-Y Transcription Factors in Sweet Potato under Salt Stress

Nuclear factor Y (NF-Y) is a heterotrimeric complex composed of three unique subunits: NF-YA, NF-YB, and NF-YC. This transcription factor complex binds to the CCAAT box of eukaryotic promoters, playing a crucial role in various biological processes in plants. Despite its importance, the NF-Y gene family has not been reported in the sweet potato (Ipomoea batatas) genome, an important food and energy crop. Understanding the role and function of NF-Y in sweet potatoes could provide valuable insights for genetic improvement and yield enhancement. To address this gap, our research aimed to comprehensively catalog and characterize the NF-Y genes in sweet potatoes, which we refer to as ‘IbNF-Y’, where ‘Ib’ denotes Ipomoea batatas. A total of 37 NF-Ys were identified, including 11 NF-YA, 21 NF-YB, and 5 NF-YC members, and their phylogeny, gene structure, chromosomal distribution, and conserved motifs were analyzed. Additionally, we assessed their expression patterns under salt stress in both light and dark conditions using transcriptome sequencing. Notably, we discovered that certain IbNF-Y genes showed significant changes in expression under salt stress, suggesting their potential roles in sweet potato’s adaptation to saline environments. Furthermore, our work enriches the genomics and genetic research on sweet potatoes and contributes valuable knowledge to the broader scientific community of the Convolvulaceae family.

Ferredoxin: a novel antimicrobial peptide derived from the black scraper (Thamnaconus modestus)

Ferredoxin (FDX) is a highly conserved iron-sulfur protein that participates in redox reactions and plays an important role as an electron transport protein in biological processes. However, its function in marine fish remains unclear. We identified two ferrodoxin proteins, FDX1 and FDX2, from black scraper (Thamnaconus modestus) to confirm their genetic structures and expression profiles and to investigate their antimicrobial activity properties by fabricating them with antimicrobial peptides based on sequences. The two TmFDXs mRNAs were most abundant in peripheral blood leukocytes of healthy T. modestus. After artificial infection with Vibrio anguillarum, a major pathogen of T. modestus, TmFDX1 mRNA was significantly upregulated in the gills, heart, intestines, kidneys, liver, and spleen, but was consistently downregulated in the brain. The expression levels of TmFDX2 mRNA were significantly upregulated in the heart, intestines, kidneys, liver, and spleen; however, no significant changes in expression were observed in the brain or gills. Based on the 2Fe-2S ferredoxin-type iron-sulfur-binding domain sequence, two peptides (pFDX1 and pFDX2) were synthesized. The bactericidal effect, biofilm formation inhibition, and gDNA-binding activity of these peptides were investigated. These findings highlight the potential as a natural peptide candidate for TmFDXs.

Comprehensive characterization of islet remodeling in development and in diabetes using mass cytometry.

The pancreatic islet is the functional and structural unit of the pancreatic endocrine portion. Islet remodeling occurs in both normal development and pathogenesis of type 1 (T1D) and type 2 diabetes (T2D). However, accurately quantifying changes in islet cellular makeup and hormone expressions poses significant challenges due to large intra- and inter-donor heterogeneity and the limited scalability of traditional methods such as immunostaining. The cytometry by time-of-flight (CyTOF) technology enables simultaneous quantification of over 30 protein markers at the single-cell resolution in a high throughput fashion. Moreover, with distinct DNA and viability markers, single live cells can be explicitly selected in CyTOF. Here, leveraging the CyTOF data generated by the Human Pancreas Analysis Program (HPAP), we characterized more than 12 million islet cells from 71 donors. Our data revealed continued age-related changes in islet endocrine cell compositions, but the maturity of endocrine cells is reached by three years of age. We also observed significant changes in beta cell numbers and key protein expressions, along with a significant increase in bihormonal cells in T1D donors. In contrast, T2D donors exhibited minimal islet remodeling events. Our data shine a light on the islet dynamics during development and diabetes pathogenesis and suggest divergent pathogenesis processes of T1D and T2D. Our comprehensive approach not only elucidates islet plasticity but also establishes a foundation for integrated CyTOF analysis in islet biology and beyond.

LL-37 and bisphosphonate co-delivery 3D-scaffold with antimicrobial and antiresorptive activities for bone regeneration

This study introduces a novel 3D scaffold for bone regeneration, composed of silk fibroin, chitosan, nano-hydroxyapatite, LL-37 antimicrobial peptide, and pamidronate. The scaffold addresses a critical need in bone tissue engineering by simultaneously combating bone infections and promoting bone growth. LL-37 was incorporated for its broad-spectrum antimicrobial properties, while pamidronate was included to inhibit bone resorption. The scaffold's porous structure, essential for cell infiltration and nutrient diffusion, was achieved through a freeze-drying process. In vitro assessments using SEM and FTIR confirmed the scaffold's morphology and chemical integrity. Antimicrobial efficacy was tested against pathogens of Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa). In vivo studies in a murine model of infectious bone defect revealed the scaffold's effectiveness in reducing inflammation and bacterial load, and promoting bone regeneration. RNA sequencing of treated specimens provided insights into the molecular mechanisms underlying these observations, revealing significant gene expression changes related to bone healing and immune response modulation. The results indicate that the scaffold effectively inhibits bacterial growth and supports bone cell functions, making it a promising candidate for treating infectious bone defects. Future studies should focus on optimizing the release of therapeutic agents and evaluating the scaffold's clinical potential.

Informing Hazard Identification and Risk Characterization of Environmental Chemicals by Combining Transcriptomic and Functional Data from Human-Induced Pluripotent Stem-Cell-Derived Cardiomyocytes.

Environmental chemicals may contribute to the global burden of cardiovascular disease, but experimental data are lacking to determine which substances pose the greatest risk. Human-induced pluripotent stem cell (iPSC)-derived cardiomyocytes are a high-throughput cardiotoxicity model that is widely used to test drugs and chemicals; however, most studies focus on exploring electro-physiological readouts. Gene expression data may provide additional molecular insights to be used for both mechanistic interpretation and dose-response analyses. Therefore, we hypothesized that both transcriptomic and functional data in human iPSC-derived cardiomyocytes may be used as a comprehensive screening tool to identify potential cardiotoxicity hazards and risks of the chemicals. To test this hypothesis, we performed concentration-response analysis of 464 chemicals from 12 classes, including both pharmaceuticals and nonpharmaceutical substances. Functional effects (beat frequency, QT prolongation, and asystole), cytotoxicity, and whole transcriptome response were evaluated. Points of departure were derived from phenotypic and transcriptomic data, and risk characterization was performed. Overall, 244 (53%) substances were active in at least one phenotype; as expected, pharmaceuticals with known cardiac liabilities were the most active. Positive chronotropy was the functional phenotype activated by the largest number of tested chemicals. No chemical class was particularly prone to pose a potential hazard to cardiomyocytes; a varying proportion (10-44%) of substances in each class had effects on cardiomyocytes. Transcriptomic data showed that 69 (15%) substances elicited significant gene expression changes; most perturbed pathways were highly relevant to known key characteristics of human cardiotoxicants. The bioactivity-to-exposure ratios showed that phenotypic- and transcriptomic-based POD led to similar results for risk characterization. Overall, our findings demonstrate how the integrative use of in vitro transcriptomic and phenotypic data from iPSC-derived cardiomyocytes not only offers a complementary approach for hazard and risk prioritization, but also enables mechanistic interpretation of the in vitro test results to increase confidence in decision-making.

Enhancing Pseudomonas syringae pv. Actinidiae sensitivity in kiwifruit by repressing the NBS-LRR genes through miRNA-215-3p and miRNA-29-3p identification.

Kiwifruit bacterial canker, caused by Pseudomonas syringae pv. actinidiae (PSA), poses a grave threat to the global kiwifruit industry. In this study, we examined the role of microRNAs (miRNAs) in kiwifruit's response to PSA. Kiwifruit seedlings subjected to PSA treatment showed significant changes in both miRNA and gene expression compared to the control group. We identified 364 differentially expressed miRNAs (DEMs) and 7170 differentially expressed genes (DEGs). Further analysis revealed 180 miRNAs negatively regulating 641 mRNAs. Notably, two miRNAs from the miRNA482 family, miRNA-215-3p and miRNA-29-3p, were found to increase kiwifruit's sensitivity to PSA when overexpressed. These miRNAs were linked to the regulation of NBS-LRR target genes, shedding light on their role in kiwifruit's defence against PSA. This study offers insights into the miRNA482-NBS-LRR network as a crucial component in enhancing kiwifruit bioresistance to PSA infestation and provides promising candidate genes for further research.

Jamaican fruit bat (Artibeus jamaicensis) insusceptibility to mucosal inoculation with SARS-CoV-2 Delta variant is not caused by receptor compatibility

The ancestral sarbecovirus giving rise to SARS-CoV-2 is posited to have originated in bats. While SARS-CoV-2 causes asymptomatic to severe respiratory disease in humans, little is known about the biology, virus tropism, and immunity of SARS-CoV-2-like sarbecoviruses in bats. SARS-CoV-2 has been shown to infect multiple mammalian species, including various rodent species, non-human primates, and Egyptian fruit bats. We show that SARS-CoV-2 can utilize Jamaican fruit bat (Artibeus jamaicensis) ACE2 spike for entry in vitro. Therefore, we investigate the Jamaican fruit bat as a possible in vivo model to study reservoir responses. We find that SARS-CoV-2 Delta does not efficiently replicate in Jamaican fruit bats in vivo. We observe infectious viruses in the lungs of only one animal on day 1 post-inoculation and find no evidence of shedding or seroconversion. This is possibly due to host factors restricting virus egress after aborted replication. Furthermore, we observe no significant immune gene expression changes in the respiratory tract but do observe changes in the intestinal metabolome after inoculation. This suggests that, despite its broad host range, SARS-CoV-2 is unable to infect all bat species, and Jamaican fruit bats are not an appropriate model to study SARS-CoV-2 reservoir infection.

Effect of Triclisia subcordata Oliv. (Menispermaceae) leaves on hormonal imbalance and genes expression in the ovaries of letrozole-induced polycystic rats via in vivo and computational approaches

The hormonal imbalance, insulin sensitivity, and ovarian function are among the biological processes linked to polycystic ovarian syndrome (PCOS). Hence, in PCOS ovaries, the impact of Triclisia subcordata Oliv. leaf (TSL) on hormone levels and the expression of the genes FTO, CYP11A, IRS, P53, and HSD17B2 was studied. Comparable to a normal control group, the rats treated with TSL methanol extract had the lowest levels of testosterone and the highest quantity of the follicle-stimulating hormone. In the ovaries of PCOS rats, TSL methanol extract strongly reduced HSD17B2 expression and significantly increased IRS expression. Furthermore, significant changes in FTO expression were detected, suggesting possible correlations with metabolic disorders, hormone dysregulation, and features of ovarian function. Additionally, P53 expression significantly decreased. GC-MS analysis revealed the presence of farnesol formate, 4-(4-ethylcyclohexyl) -1-pentyl, and cyclohexene as phytoconstituents. In T. subcordata leaves, cyclohexene, 4-(4-ethylcyclohexyl)-1-pentyl-, and farnesol formate showed a more unusual and specific binding to the p53 core, FTO protein, and cytochrome P450 CYP11A1 domains. According to the molecular dynamics study, one of the main mechanisms that have been proposed for the recovery of metabolic syndrome in affected individuals is the stabilization of proteins by the binding of these chemicals to the targeted structure. All these results suggest that Triclisia subcordata leaves may have complex impacts on PCOS-related molecular pathways, including restoring normalcy to insulin sensitivity, androgen metabolism, hormone balance, and ovarian function.

Deletion of an evolutionarily conserved TAD boundary compromises spermatogenesis in mice.

Spermatogenesis is a complex process that can be disrupted by genetic and epigenetic changes, potentially leading to male infertility. Recent research has rapidly increased the number of protein coding mutations causally linked to impaired spermatogenesis in humans and mice. However, the role of non-coding mutations remains largely unexplored. As a case study to evaluate the effects of non-coding mutations on spermatogenesis, we first identified an evolutionarily conserved topologically associated domain (TAD) boundary near two genes with important roles in mammalian testis function: Dmrtb1 and Lrp8 . We then used CRISPR-Cas9 to generate a mouse line where 26kb of the boundary was removed including a strong and evolutionarily conserved CTCF binding site. ChIP-seq and Hi-C experiments confirmed the removal of the CTCF site and a resulting increase in the DNA-DNA interactions across the domain boundary. Mutant mice displayed significant changes in testis gene expression, abnormal testis histology, a 35% drop in the estimated efficiency of spermatogenesis and a 28% decrease in daily sperm production compared to littermate controls. Despite these quantitative changes in testis function, mutant mice show no significant changes in fertility. This suggests that non-coding deletions affecting testis gene regulation may have smaller effects on fertility compared to coding mutations of the same genes. Our results demonstrate that disruption of a TAD boundary can have a negative impact on sperm production and highlight the importance of considering non-coding mutations in the analysis of patients with male infertility.

Plant volatile-triggered defense in citrus against biotic stressors.

Plants employ sophisticated defense mechanisms, including releasing volatile organic compounds, to defend against biotic and abiotic stresses. These compounds play a crucial role in plant defense by attracting natural enemies and facilitating communication between plants to activate defense mechanisms. However, there has been no research on how exposure to these compounds activates defense mechanisms in citrus plants. To elucidate the underlying mechanisms governing citrus defensive activation, we conducted a molecular analysis of the rootstock Citrange carrizo [a hybrid of Citrus sinensis × Poncirus trifoliata] in response to defense activation by the volatile (Z)-3-hexenyl propanoate [(Z)-3-HP], utilizing a groundbreaking transcriptomic analysis involving the genomes of both parental species. Our results revealed significant gene expression changes, notably the overexpression of genes related to plant immunity, antioxidant activity, defense against herbivores, and tolerance to abiotic stress. Significantly, P. trifoliata contributed most notably to the hybrid's gene expression profile in response to (Z)-3-HP. Additionally, plants exposed to (Z)-3-HP repelled several citrus pests, attracted natural predators, and led to diminished performance of two key citrus pests. Our study emphasizes the complex molecular basis of volatile-triggered defenses in citrus and highlights the potential of plant volatiles in pest control strategies.

Nematode Galectin Inhibits Basophilic Leukaemia RBL-2H3 Cells Apoptosis in IgE-Mediated Activation.

Mast cells are essential immune cells involved in the host's defence against gastrointestinal nematodes. To evade the immune response, parasitic nematodes produce a variety of molecules. Galectin 1, produced by Teladorsagia circumcincta (Tci-gal-1), reduces mast cell degranulation and selectively regulates mediator production and release in an IgE-dependent manner. To uncover the activity of Tci-gal-1, we have examined the effect of the protein on gene expression, protein production, and apoptosis in activated basophilic leukaemia RBL-2H3 cells. Rat RBL-2H3 cells were activated with anti-DNP IgE and DNP-HSA, and then treated with Tci-gal-1. Microarray analysis was used to examine gene expression. The levels of several apoptosis-related molecules and cytokines were determined using antibody arrays and ELISA. Early and late apoptosis was evaluated cytometrically. Degranulation of cells was determined by a β-hexosaminidase release assay. Treatment of activated RBL-2H3 cells with Tci-gal-1 resulted in inhibited apoptosis and decreased degranulation, although we did not detect significant changes in gene expression. The production of pro-apoptotic molecules, receptor for advanced glycation end products (RAGE) and Fas ligand (FasL), and the cytokines IL-9, IL-10, IL-13, TNF-α, and IL-2 was strongly inhibited. Tci-gal-1 modulates apoptosis, degranulation, and production of cytokines by activated RBL-2H3 cells without detectable influence on gene transcription. This parasite protein is crucial for modulation of the protective immune response and the inhibition of chronic inflammation driven by mast cell activity.

Vitamin D Receptor Regulates Liver Regeneration After Partial Hepatectomy in Male Mice.

Vitamin D signals through the vitamin D receptor (VDR) to induce its end-organ effects. Hepatic stellate cells control development of liver fibrosis in response to stressors and vitamin D signaling decreases fibrogenesis. VDR expression in hepatocytes, however, is low in healthy liver, and the role of VDR in hepatocyte proliferation is unclear. Hepatocyte-VDR null mice (hVDR) were used to assess the role of VDR and vitamin D signaling in hepatic regeneration. hVDR mice have impaired liver regeneration and impaired hepatocyte proliferation associated with significant differential changes in bile salts. Notably, mice lacking hepatocyte VDR had significant increases in expression of conjugated bile acids after partial hepatectomy, consistent with failure to normalize hepatic function by the 14-day time point tested. Real-time PCR of hVDR and control livers showed significant changes in expression of cell cycle genes including cyclins D1 and E1 and cyclin-dependent kinase 2. Gene expression profiling of hepatocytes treated with vitamin D or control showed regulation of groups of genes involved in liver proliferation, hepatitis, liver hyperplasia/hyperproliferation and liver necrosis/cell death. Together these studies demonstrate an important functional role for VDR in hepatocytes during liver regeneration. Combined with the known profibrotic effects of impaired VDR signaling in stellate cells, the studies provide a mechanism whereby vitamin D deficiency would both reduce hepatocyte proliferation and permit fibrosis, leading to significant liver compromise.

The effect of preoperative hormonal stimulation on the urethral plate; A histologic and histochemical study

Preoperative hormone stimulation (PHS) is used to increase the glans size and may improve the cosmetic appearance after hypospadias surgery. The exact effect of PHS on different penile tissues remains unclear and controversial. Previous studies showed that PHS increased vessel density in the foreskin. However, the effect of PHS on the urethral has never been studied before. In this study we examine the PHS effects on the urethral plate. Specimens of the urethral plate and the underlying tissue were excised to correct severe chordee in 16 children with proximal and perineal hypospadias with severe chordee in 2 groups. Group A consisted of 8 children received PHS prior to surgery. Group B included 8 children with proximal and perineal hypospadias with severe chordee who did not receive PHS and served as a control group. Specimens were examined blindly using hematoxylin-eosin and elastic van-Gieson stain as well as factor 8 and SMA antibodies. The median age of Group A was 13 (range 10-20) months. The median age of Group B (without prior PHS) was 17 (range 14-29) months (p=0,03). The median vessel-density in group A (82 vessels per mm2) was significantly higher than in Group B (65 per mm2), (p<0.05). The median vessel diameter was also significantly higher in Group A (13μm) than in Group B (11μm), (p<0.05). The median epithelial layer thickness in Group A was 110μm and in Group B 98μm, but showed no statistical significance (p=0,16). There was no significant change in dartos fascia layer thickness or androgen receptor expression. There was no visual change in the organization of elastic fibers. This study is the first study to document the effect of PHS on the urethral plate in hypospadias with severe chordee. PHS significantly increased the median vessel-density as well as median vessel diameter as compared to a matching control group. The findings of the study may justify PHS administration before the first operation to improve the vascularity and may reduce the severity of chordee.

Analysis of culture and RNA isolation methods for precision-cut liver slices from cirrhotic rats

Precision-cut liver slices (PCLS) are increasingly used as a model to investigate anti-fibrotic therapies. However, many studies use PCLS from healthy animals treated with pro-fibrotic stimuli in culture, which reflects only the early stages of fibrosis. The effects of different culture conditions on PCLS from cirrhotic animals has not been well characterized and there is no consensus on optimal methods. In this study, we report a method for the collection and culture of cirrhotic PCLS and compare the effect of common culture conditions on viability, function, and gene expression. Additionally, we compared three methods of RNA isolation and identified a protocol with high yield and purity. We observed significantly increased albumin production when cultured with insulin-transferrin-selenium and dexamethasone, and when incubated on a rocking platform. Culturing with insulin-transferrin-selenium and dexamethasone maintained gene expression closer to the levels in fresh slices. However, despite stable viability and function up to 4 days, we found significant changes in expression of key genes by day 2. Interestingly, we also observed that cirrhotic PCLS maintain viability in culture longer than slices from healthy animals. Due to the influence of matrix stiffness on fibrosis and hepatocellular function, it is important to evaluate prospective anti-fibrotic therapies in a platform that preserves tissue biomechanics. PCLS from cirrhotic animals represent a promising tool for the development of treatments for chronic liver disease.

P-400 Pregnancy-specific glycoproteins - potential markers for risk associated with preeclampsia during gestational SARS-CoV-2 Infection

Abstract Study question Could pregnancy-specific glycoproteins serve as potential markers for the risk of developing preeclampsia during gestational SARS-CoV-2 Infection? Summary answer Pregnancy-specific glycoproteins (PSGs) are significantly down-regulated in women with gestational SARS-CoV-2 infection, which could be used to diagnose high-risk pregnancies in assisted reproductive treatment (ART). What is known already In vitro fertilization (IVF) pregnancies are precious and face increased risks of preeclampsia. Similarly, SARS-CoV-2 infection during pregnancy increases the risk for preeclampsia. Precious pregnancies with ART along with SARS-CoV-2 infection can further exacerbate the risk for preeclampsia, affecting both maternal and fetal health. Thus, identifying molecular markers associated with preeclampsia risk in the context of SARS-CoV-2 infection is crucial for maternal and fetal health management, specifically in pregnancies with IVF. Study design, size, duration Placental samples (n = 16) were collected at term delivery from SARS-CoV-2 positive women (n = 7) and negative healthy women (n = 9). We studied separately, the gene expression pattern in maternal and fetal placental compartments. Interesting genes from RNA sequencing results were validated using real-time PCR. Participants/materials, setting, methods All pregnant women at their term delivery were clinically tested for SARS-CoV-2 infection by PCR. Maternal and fetal sides of placenta were collected in total RNA was extracted from the snap-frozen tissues. cDNA libraries were constructed using Smart-seq2 method and sequenced using Illumina NovaSeq 6000 sequencing platform. Bioinformatic analysis was using Partek® Flow® software, v9.0, DEGs were identified by applying FDR ≤ 0.05. qPCR was for validating the interesting genes. Main results and the role of chance Our analysis revealed 635 DEGs in the maternal placental tissue, with 518 upregulated and 117 downregulated genes in SARS-CoV-2-positive women compared with the healthy SARS-CoV-2-negative women. In contrast, the fetal compartment did not exhibit any significant changes in gene expression with SARS-CoV-2 infection. In the maternal compartment, we observed significant downregulation of nine genes belonging to the pregnancy-specific glycoprotein related to the immunoglobulin superfamily with active SARS-CoV-2 infection (fold change range from −13.70 to − 5.28; FDR ≤ 0.01). Additionally, comparing symptomatic women with healthy women, we identified 1788 DEGs. Furthermore, pathway enrichment analysis revealed that pathways related to oxidative phosphorylation, insulin secretion, cortisol synthesis, estrogen signaling, oxytocin signaling, and antigen processing were altered significantly in symptomatic women. Limitations, reasons for caution We have a limited sample size in this study, though we collected placental samples from all the women who were positive for SARS-CoV-2, at admission for delivery. Studies with larger sample sizes are warranted to further reconfirm the results. In vitro studies may help us to deepen our understanding. Wider implications of the findings This study sheds light on PSGs as potential biomarkers for risk for preeclampsia during gestational SARS-CoV-2 and reveals molecular pathways associated with an increased clinical risk of preeclampsia with COVID-19 during pregnancy. The findings offer valuable insights that could be further explored clinically in managing pregnant women with COVID-19. Trial registration number not applicable

Physiological and transcriptomic analysis reveals the toxicological mechanisms of polystyrene micro- and nano-plastics in Chlamydomonas reinhardtii

With the accumulation of plastic waste in the environment, the toxicity of micro- and nano-plastics (MNPs) to microalgae has attracted increasing attention. However, the underlying toxic mechanisms of MNPs remain to be elucidated. In this study, we synthesized micro- and nano-scale of polystyrene MNPs (PS MNPs) to investigate their toxicity and toxic mechanisms in Chlamydomonas reinhardtii. We found that PS MNPs significantly inhibit the production of photosynthetic pigments and increase soluble protein content. The detailed analysis of results shows that both materials affect photosynthetic efficiency by damaging the donor side, reaction center, and electron transfer of photosystem II. Moreover, compared to PS MPs, PS NPs have a greater negative impact on algal cells. Analyzing the transcriptome of cells suggests that the most sensitive metabolic pathways in response to PS MNPs involve oxidative phosphorylation, biosynthesis of secondary metabolites, and photosynthesis. Especially, genes related to photosynthesis and oxidative phosphorylation showed significant changes in expression after exposure to PS MNPs. This study provided molecular-level insights into the toxic mechanisms of PS MNPs on microalgae.

The effects and mechanisms of novel antibacterial amyloid peptides derived from Streptococcus mutans proteome

Streptococcus mutans (S. mutans) is one of the primary cariogenic pathogens. Recently the aggregation prone region (APR) has been applied to develop novel antibacterial amyloid peptides due to its ability to target and trigger the aggregation of proteins containing similar APRs. In this study, we modified 63 novel amyloid peptides based on the APRs screened from S. mutans proteome. Three of the peptides exhibited significant antibacterial activity against S. mutans, but without specificity. Transmission electron microscope (TEM), stain of Congo red and ThT, and Fourier transform infrared spectroscopy (FTIR) showed that the antimicrobial amyloid peptides (C9 and C12) aggregated into unmature fibrils, not typical morphology of mature amyloid fibrils. Distortion and perforation of cell membrane were observed by various microscopes. Membrane permeabilization assay and SYTO9/PI staining assay verified that the membrane permeability increased after being treated by C9 and C12. Aggregates and unmature fibrils could be observed inside dead cells in the ultrathin sections by TEM. Transcriptome sequencing (RNA-seq) detected the significant expression changes of genes related to protein aggregates formation (dnaK, groL and groES) and metabolism (gtfB), which was further verified by quantitative real-time PCR (qRT-PCR). In conclusion, we innovatively developed antimicrobial amyloid peptides based on the APRs in S. mutans proteome and found their combination antimicrobial mechanism of damaging the membrane with triggering protein aggregation, which might shed light on novel antibacterial peptides development.