Nanoarchitectonics of Injectable Biomimetic Conjugates for Cartilage Protection and Therapy Based on Degenerative Osteoarthritis Progression.

Osteoarthritis (OA) is a common age-related degenerative disease characterized by changes in the local tissue environment as inflammation progresses. Inspired by the wind-dispersal mechanism of dandelion seeds, this study develops responsive biomimetic microsphere-drug conjugate for OA therapy and protection. The conjugate integrates dibenzaldehyde polyethylene glycol (DFPEG) with chitosan and polyethylene glycol diacrylate (PEGDA) through dynamic covalent bonds to form a dual-network hydrogel microsphere. Based on the progression of OA, the conjugate with the surface-anchored cyclic peptide cortistatin-14 (CST-14) achieves targeted drug therapy and a self-regulating hydrogel network. In cases of progressing inflammation (pH < 5), CST-14 dissociates from the microsphere surface (viz. the drug release rate increased) and inhibits TNF-α signaling to suppress OA. Concurrently, the monomer DFPEG responsively detaches from the hydrogel network and scavenges reactive oxygen species (ROS) to protect the cartilage tissue. The ROS scavenging of DFPEG is comparable to that of coenzyme Q10 and vitamin C. The degraded PEGDA microspheres provide tissue lubrication through reused conjugates. The rat OA model successfully achieved a synergistic therapeutic effect greater than the additive effect (1 + 1 > 2). This strategy offers an approach for anchoring amine-containing drugs and has marked potential for OA treatment and protection.

Biostimulation accelerates landfill stabilization and resource utilization efficiency, providing feasible technical support for the overall lifecycle management of landfills.

Although sanitary landfill is one of the principal municipal solid waste (MSW) treatment and disposal methods, its limitations, such as insufficient use of resources, long stability time, and high risk of environmental pollution, must be urgently resolved. The effect of multifunctional microbial community (MMC) inoculation on MSW landfill process was investigated using simulated anaerobic bioreactor landfill (ABL), and composition and microbial community structure of waste, leachate water quality, and gas production were monitored. MMC inoculation significantly accelerated lignocellulose degradation, and the (Hemicellulose content + Cellulose content)/Lignin content ((C + H)/L) of MMC inoculation treatment was 0.89 ± 0.04 on day 44, which was significantly lower than that of the control group (1.14 ± 0.02). At the end of the landfill process, the reductive organic matter, ammonia nitrogen, and volatile fatty acids in the leachate of the MMC group decreased to 9400.00 ± 288.68, 332.78 ± 5.77, and 79.33 ± 6.44 mg L-1, respectively, significantly lower than those of the control group (24,167.00 ± 208.17, 551.14 ± 5.60, and 156.33 ± 8.22 mg L-1). Meanwhile, MMC inoculation increased the methane production to 118.12 ± 5.42 L kg-1 of dry matter, significantly higher than the output of the control group (60.60 ± 2.24 L kg-1). MMC inoculation optimized the microbial community structure in ABL and increased lignocellulose-degrading microorganisms (Brevundimonas, Cellvibrio, Leifsonia, and Devosia) and methanogen (Methanosaeta and Methanoculleus) abundance in the middle stage of landfill. Moreover, MMC introduction improved the abundance of carbon metabolism enzymes and increased saprophytic fungal abundance by 30.09% in the middle stage of landfill. Overall, these findings may help in developing an effective method to increase the lifespan of landfills and enhance their post-closure management.

Relation between blood pressure time in range and composite cardiovascular outcomes in patients with primary aldosteronism: a retrospective case study.

PURPOSE: To investigate the association between blood pressure (BP) time in range (TIR) and composite cardiovascular outcomes in patients with primary aldosteronism (PA). METHODS: Between January 2019 and December 2021, 47 patients with PA were recruited from the First Affiliated Hospital of Xiamen University. Twenty-four-hour ambulatory BP monitoring (ABPM) and cardiovascular outcomes were assessed in all patients during the first diagnosis of PA. RESULTS: The mean age of the patients was 48.8 ± 11.4 years. Compared to PA without composite cardiovascular outcomes, the nighttime systolic BP TIR [31.2% (6.2%, 81.2%) vs. 11.5% (0.0%, 29.7%), p = 0.02] and defined daily dose (DDDs) of antihypertensive medication [2.0 (1.0, 2.8) vs. 1.0 (1.0, 2.0), p = 0.03] were lower in PA patients with composite cardiovascular outcomes, while higher glucose (5.0 ± 1.0 mmol/L vs. 5.9 ± 1.5 mmol/L) and prevalence of a history of alcohol intake was higher in PA patients with composite cardiovascular outcomes. There were no differences in age, sex, BMI, smoking, duration of hypertension, lipid levels, aldosteronism, clinic BP, 24-hour mean BP, daytime or nighttime BP, percentage of nocturnal SBP or DBP decline, 24-hour BP TIR, daytime BP TIR, or nighttime DBP TIR between the two groups. After adjusting for confounding factors, nighttime systolic BP TIR was significantly associated with composite cardiovascular outcomes (adjusted OR = 0.92 [95% CI 0.86, 0.99]) in multiple logistic regression analysis. CONCLUSION: Nighttime systolic BP TIR was significantly associated with composite cardiovascular outcomes in patients with PA.

A novel strategy for detoxification of deoxynivalenol via modification of both toxic groups.

Deoxynivalenol (DON) is the most abundant mycotoxin in cereal crops and derived foods and is of great concern in agriculture. Bioremediation strategies have long been sought to minimize the impact of mycotoxin contamination, but few direct and effective enzyme-catalyzed detoxification methods are currently available. In this study, we established a multi-enzymatic cascade reaction and successfully achieved detoxification at double sites: glutathionylation for the C-12,13 epoxide group and epimerization for the C-3 hydroxyl group. This yielded novel derivatives of DON, 3-epi-DON-13-glutathione (3-epi-DON-13-GSH) as well as its by-product, 3-keto-DON-13-GSH, for which precise structures were validated via liquid chromatography-high-resolution tandem mass spectrometry (LC-HRMS) and nuclear magnetic resonance (NMR) spectroscopy. Both cell viability and DNA synthesis assays demonstrated dramatically decreased cytotoxicity of the double-site modified product 3-epi-DON-13-GSH. These findings provide a promising and urgently needed novel method for addressing the problem of DON contamination in agricultural and industrial settings.

Synergistic action and mechanism of scoparone, a key bioactive component of Artemisia capillaris, and spirodiclofen against spider mites.

BACKGROUND: Plants have numerous defensive secondary metabolites to withstand insect attacks. Scoparone, which is extracted from the medicinal plant Artemisia capillaris, has potent acaricidal effects on Tetranychus cinnabarinus. Spirodiclofen, derived from a tetronic acid derivative, is a potent commercial acaricide that is extensively used globally. However, whether scoparone has synergistic effects when used in conjunction with spirodiclofen and the underlying synergistic mechanism remains unclear. RESULTS: Scoparone exhibited a potent synergistic effect when it was combined with spirodiclofen at a 1:9 ratio. Subsequently, cytochrome P450 monooxygenase (P450) activity, RNA-Seq and qPCR assays indicated that the enzyme activity of P450 and the expression of one P450 gene from T. cinnabarinus, TcCYP388A1, were significantly inhibited by scoparone and spirodiclofen + scoparone; conversely, P450 was activated in spirodiclofen-exposed mites. Importantly, RNAi-mediated silencing of the TcCYP388A1 gene markedly increased the susceptibility of spider mites to spirodiclofen, scoparone and spirodiclofen + scoparone, and in vitro, the recombinant TcCYP388A1 protein could metabolize spirodiclofen. Molecular docking and functional analyses further indicated that R117, which is highly conserved in Arachnoidea species, may be a vital specific binding site for scoparone in the mite TcCYP388A1 protein. This binding site was subsequently confirmed using mutagenesis data, which revealed that this binding site was the sole site selected by scoparone in spider mites over mammalian or fly CYP388A1. CONCLUSIONS: These results indicate that the synergistic effects of scoparone and spirodiclofen on mites occurs through the inhibition of P450 activity, thus reducing spirodiclofen metabolism. The synergistic effect of this potent natural product on the detoxification enzyme-targeted activity of commercial acaricides may offer a sustainable strategy for pest mite resistance management. © 2024 Society of Chemical Industry.

Feasibility and limitations of combined treatment for lateral pelvic lymph node metastases in rectal cancer.

Colorectal cancer ranks among the most commonly diagnosed cancers globally, and is associated with a high rate of pelvic recurrence after surgery. In efforts to mitigate recurrence, pelvic lymph node dissection (PLND) is commonly advocated as an adjunct to radical surgery. Neoadjuvant chemoradiotherapy (NACRT) is a therapeutic approach employed in managing locally advanced rectal cancer, and has been found to increase the survival rates. Chua et al have proposed a combination of NACRT with selective PLND for addressing lateral pelvic lymph node metastases in rectal cancer patients, with the aim of reducing recurrence and improving survival outcomes. Nevertheless, certain studies have indicated that the addition of PLND to NACRT and total mesorectal excision did not yield a significant reduction in local recurrence rates or improvement in survival. Consequently, meticulous patient selection and perioperative chemotherapy may prove indispensable in ensuring the efficacy of PLND.

Identification and experimental validation of immune-related gene PPARG is involved in ulcerative colitis.

BACKGROUND: The pathophysiology of ulcerative colitis (UC) is believed to be heavily influenced by immunology, which presents challenges for both diagnosis and treatment. The main aims of this study are to deepen our understanding of the immunological characteristics associated with the disease and to identify valuable biomarkers for diagnosis and treatment. METHODS: The UC datasets were sourced from the GEO database and were analyzed using unsupervised clustering to identify different subtypes of UC. Twelve machine learning algorithms and Deep learning model DNN were developed to identify potential UC biomarkers, with the LIME and SHAP methods used to explain the models' findings. PPI network is used to verify the identified key biomarkers, and then a network connecting super enhancers, transcription factors and genes is constructed. Single-cell sequencing technology was utilized to investigate the role of Peroxisome Proliferator Activated Receptor Gamma (PPARG) in UC and its correlation with macrophage infiltration. Furthermore, alterations in PPARG expression were validated through Western blot (WB) and immunohistochemistry (IHC) in both in vitro and in vivo experiments. RESULT: By utilizing bioinformatics techniques, we were able to pinpoint PPARG as a key biomarker for UC. The expression of PPARG was significantly reduced in cell models, UC animal models, and colitis models induced by dextran sodium sulfate (DSS). Interestingly, overexpression of PPARG was able to restore intestinal barrier function in H2O2-induced IEC-6 cells. Additionally, immune-related differentially expressed genes (DEGs) allowed for efficient classification of UC samples into neutrophil and mitochondrial metabolic subtypes. A diagnostic model incorporating the three disease-specific genes PPARG, PLA2G2A, and IDO1 demonstrated high accuracy in distinguishing between the UC group and the control group. Furthermore, single-cell analysis revealed that decreased PPARG expression in colon tissue may contribute to the polarization of M1 macrophages through activation of inflammatory pathways. CONCLUSION: In conclusion, PPARG, a gene related to immunity, has been established as a reliable potential biomarker for the diagnosis and treatment of UC. The immune response it controls plays a key role in the progression and development of UC by enabling interaction between characteristic biomarkers and immune infiltrating cells.

The CDK9 inhibitor enitociclib overcomes resistance to BTK inhibition and CAR-T therapy in mantle cell lymphoma.

Inhibitors of Bruton's tyrosine kinase (BTKi) and chimeric antigen receptor T-cell (CAR-T) therapy targeting CD19 are paradigm-shifting advances in treating patients with aggressive mantle cell lymphoma (MCL). However, clinical relapses following BTKi and CD19-directed CAR-T treatments are a fast-growing medical challenge. Development of novel therapies to overcome BTKi resistance (BTKi-R) and BTKi-CAR-T dual resistance (Dual-R) are urgently needed. Our single-cell RNA sequencing data revealed major transcriptomic reprogramming, with great enrichment of MYC-targets evolving as resistance to these therapies developed. Interestingly, cyclin-dependent kinase 9 (CDK9), a critical component of the positive transcription elongation factor-b complex, was among the top upregulated genes in Dual-R vs. BTKi-R samples. We therefore hypothesized that targeting CDK9 may turn off MYC-driven tumor survival and drug resistance. Enitociclib (formerly VIP152) is a selective CDK9 inhibitor whose potency against MCL has not been assessed. In this study, we found that enitociclib was highly potent in targeting lymphoma cells, with the half-maximal inhibitory concentration (IC50) ranging from 32 to 172 nM in MCL and diffuse large B-cell lymphoma cell lines. It inhibited CDK9 phosphorylation and downstream events including de novo synthesis of the short-lived proteins c-MYC, MCL-1, and cyclin D1, and induced apoptosis in a caspase-3-dependent manner. Enitociclib potently inhibited in vivo tumor growth of cell line-derived and patient-derived xenografts having therapeutic resistance. Our data demonstrate the potency of enitociclib in overcoming therapeutic resistance in MCL models and provide evidence in favor of its clinical investigation.

DeepFace: Deep-learning-based framework to contextualize orofacial-cleft-related variants during human embryonic craniofacial development.

Orofacial clefts (OFCs) are among the most common human congenital birth defects. Previous multiethnic studies have identified dozens of associated loci for both cleft lip with or without cleft palate (CL/P) and cleft palate alone (CP). Although several nearby genes have been highlighted, the "casual" variants are largely unknown. Here, we developed DeepFace, a convolutional neural network model, to assess the functional impact of variants by SNP activity difference (SAD) scores. The DeepFace model is trained with 204 epigenomic assays from crucial human embryonic craniofacial developmental stages of post-conception week (pcw) 4 to pcw 10. The Pearson correlation coefficient between the predicted and actual values for 12 epigenetic features achieved a median range of 0.50-0.83. Specifically, our model revealed that SNPs significantly associated with OFCs tended to exhibit higher SAD scores across various variant categories compared to less related groups, indicating a context-specific impact of OFC-related SNPs. Notably, we identified six SNPs with a significant linear relationship to SAD scores throughout developmental progression, suggesting that these SNPs could play a temporal regulatory role. Furthermore, our cell-type specificity analysis pinpointed the trophoblast cell as having the highest enrichment of risk signals associated with OFCs. Overall, DeepFace can harness distal regulatory signals from extensive epigenomic assays, offering new perspectives for prioritizing OFC variants using contextualized functional genomic features. We expect DeepFace to be instrumental in accessing and predicting the regulatory roles of variants associated with OFCs, and the model can be extended to study other complex diseases or traits.

syn-tasiRnas targeting the coat protein of potato virus Y confer antiviral resistance in Nicotiana benthamiana.

Trans-acting small interfering RNAs (tasiRNAs) are 21-nt phased (phased siRNAs) resulting from successive DCL-catalyzed processing from the end of a double-stranded RNA substrate originating from the RDR of an AGO-catalyzed cleaved RNA at a micro RNA target site. Plant tasiRNAs have been synthesized to produce synthetic tasiRNAs (syn-tasiRNAs) targeting viral RNAs that confer viral resistance. In this study, we engineered syn-tasiRNAs to target potato virus Y (PVY) infection by replacing five native siRNAs of TAS1c with 210-bp fragments from the coat protein (CP) region of the PVY genome. The results showed that the transient expression of syn-tasiR-CPpvy2 in Nicotiana benthamiana (N. benthamiana) plants conferred antiviral resistance, supported by the absence of PVY infection symptoms and viral accumulation. This indicated that syn-tasiR-CPpvy2 successfully targeted and silenced the PVY CP gene, effectively inhibiting viral infection. syn-tasiR-CPpvy1 displayed attenuated symptoms and decreased viral accumulation in these plants However, severe symptoms of PVY infection and a similar amount of viral accumulation as the control were observed in plants expressing syn-tasiR-CPpvy3. syn-tasiR-CPpvy/pvx, which targets both PVY and potato virus X (PVX), was engineered using a single precursor. After the transient expression of syn-tasiR-CPpvy/pvx3 and syn-tasiR-CPpvy/pvx5 in N. benthamiana, the plants were resistant to both PVY and PVX. These results suggested that engineered syn-tasiRNAs could not only specifically induce antiviral resistance against one target virus but could also be designed for multi-targeted silencing of different viruses, thereby preventing complex virus infection in plants.

Investigating gene functions and single-cell expression profiles of de novo variants in orofacial clefts.

Orofacial clefts (OFCs) are common congenital birth defects with various etiologies, including genetic variants. Online Mendelian Inheritance in Man (OMIM) annotated several hundred genes involving OFCs. Furthermore, several hundreds of de novo variants (DNVs) have been identified from individuals with OFCs. Some DNVs are related to known OFC genes or pathways, but there are still many DNVs whose relevance to OFC development is unknown. To explore novel gene functions and their cellular expression profiles, we focused on DNVs in genes that were not listed in OMIM. We collected 960 DNVs in 853 genes from published studies and curated these genes, based on the DNVs' deleteriousness, into 230 and 23 genes related to cleft lip with or without cleft palate (CL/P) and cleft palate only (CPO), respectively. For comparison, we curated 178 CL/P and 277 CPO genes from OMIM. In CL/P, the pathways enriched in DNV and OMIM genes were significantly overlapped (p = 0.002). Single-cell RNA sequencing (scRNA-seq) analysis of mouse lip development revealed that both gene sets had abundant expression in the ectoderm (DNV genes: adjusted p = 0.032, OMIM genes: adjusted p < 0.0002), while only DNV genes were enriched in the endothelium (adjusted p = 0.032). Although we did not achieve significant findings using CPO gene sets, which was mainly due to the limited number of DNV genes, scRNA-seq analysis implicated various expression patterns among DNV and OMIM genes. Our results suggest that combinatory pathway and scRNA-seq data analyses are helpful for contextualizing genes in OFC development.

Corrigendum: Sulforaphane diminishes moonlighting of pyruvate kinase M2 and interleukin 1ß expression in M1 (LPS) macrophages.

[This corrects the article DOI: 10.3389/fimmu.2022.935692.].

Molecular characterization and pathogenicity of a novel monopartite geminivirus infecting tobacco in China.

The occurrence of geminiviruses causes significant economic losses in many economically important crops. In this study, a novel geminivirus isolated from tobacco in Sichuan province of China, named tomato leaf curl Chuxiong virus (TLCCxV), was characterized by small RNA-based deep sequencing. The full-length of TLCCxV genome was determined to be 2744 nucleotides (nt) encoding six open reading frames. Phylogenetic and genome-wide pairwise identity analysis revealed that TLCCxV shared less than 91% identities with reported geminiviruses. A TLCCxV infectious clone was constructed and successfully infected Nicotiana benthamiana, N. tabacum, N. glutinosa, Solanum lycopersicum and Petunia hybrida plants. Furthermore, expression of the V2, C1 and C4 proteins through a potato virus X vector caused severe chlorosis or necrosis symptom in N. benthamiana. Taken together, we identified a new geminivirus in tobacco plants, and found that V2, C1 and C4 contribute to symptom development.

Integration of transcriptomics and metabolomics identify biomarkers of aberrant lipid metabolism in ulcerative colitis.

BACKGROUND: The incidence of ulcerative colitis (UC) continues to rise globally, but effective therapeutic targets are still lacking. In recent years, numerous studies have indicated that lipid therapies could offer a novel perspective for UC treatment. Given the absence of prior research utilizing high-throughput data to identify target genes associated with lipid metabolism, we conducted this work. METHODS: The training set for this study was derived from four datasets within the Gene Expression Omnibus (GEO), encompassing a total of 357 UC patients. We employed four machine learning methods (LASSO, SVM, RF, and Boruta) to jointly identify core biomarkers in these patients, whose aberrant expression needed to be validated in independent datasets and in dextrose sulfate sodium salt (DSS)-induced UC mouse models. Regarding metabolomics, we detected abnormal oxidized lipids in the serum of UC mouse using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in conjunction with orthogonal partial least squares-discriminant analysis (OPLS-DA). RESULTS: Phospholipase A2 Group IIA (PLA2G2A) was first identified as a possible biomarker for UC, with AUC values of 0.810 and 1.000 in the two validation sets, while in animal models the gene showed similarly significant up-regulation in damaged intestinal mucosa. Further analysis of this gene showed that it was positively correlated with 17 immune cell types and histological severity. Additionally, we pioneered the development of a lipid metabolism score in UC research, which outperformed all individual genes in terms of disease diagnostic efficacy (AUC values of 0.980 and 1.000 for the two validation sets, respectively). Finally, the metabolomics study also identified 31 significantly abnormal oxidized lipids, including 12-HHT and DHA. CONCLUSIONS: PLA2G2A is a key therapeutic target for UC, and oxidized lipids such as 12-HHT can serve as potential serologic indicators for diagnosis.

The HSP90-MYC-CDK9 network drives therapeutic resistance in mantle cell lymphoma.

Brexucabtagene autoleucel CAR-T therapy is highly efficacious in overcoming resistance to Bruton's tyrosine kinase inhibitors (BTKi) in mantle cell lymphoma. However, many patients relapse post CAR-T therapy with dismal outcomes. To dissect the underlying mechanisms of sequential resistance to BTKi and CAR-T therapy, we performed single-cell RNA sequencing analysis for 66 samples from 25 patients treated with BTKi and/or CAR-T therapy and conducted in-depth bioinformatics™ analysis. Our analysis revealed that MYC activity progressively increased with sequential resistance. HSP90AB1 (Heat shock protein 90 alpha family class B member 1), a MYC target, was identified as early driver of CAR-T resistance. CDK9 (Cyclin-dependent kinase 9), another MYC target, was significantly upregulated in Dual-R samples. Both HSP90AB1 and CDK9 expression were correlated with MYC activity levels. Pharmaceutical co-targeting of HSP90 and CDK9 synergistically diminished MYC activity, leading to potent anti-MCL activity. Collectively, our study revealed that HSP90-MYC-CDK9 network is the primary driving force of therapeutic resistance.

Single-cell multiomics decodes regulatory programs for mouse secondary palate development.

Perturbations in gene regulation during palatogenesis can lead to cleft palate, which is among the most common congenital birth defects. Here, we perform single-cell multiome sequencing and profile chromatin accessibility and gene expression simultaneously within the same cells (n = 36,154) isolated from mouse secondary palate across embryonic days (E) 12.5, E13.5, E14.0, and E14.5. We construct five trajectories representing continuous differentiation of cranial neural crest-derived multipotent cells into distinct lineages. By linking open chromatin signals to gene expression changes, we characterize the underlying lineage-determining transcription factors. In silico perturbation analysis identifies transcription factors SHOX2 and MEOX2 as important regulators of the development of the anterior and posterior palate, respectively. In conclusion, our study charts epigenetic and transcriptional dynamics in palatogenesis, serving as a valuable resource for further cleft palate research.

The Gene Expression Profiles Associated with Maternal Nicotine Exposure in the Liver of Offspring Mice.

This study aims to investigate the effect of maternal nicotine exposure on the gene expression profiles in the liver of offspring mice. Pregnant mice were subcutaneously injected with either saline vehicle or nicotine twice a day on gestational days 11-21. Total RNA from the liver samples which collected from the offspring mice of postnatal day 7 and 21 was subjected to RNA sequencing. Gene Ontology (GO) functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathway enrichment analysis were conducted to identify the functions of differentially expressed genes (DEGs). Four genes were selected for further validation by quantitative reverse transcription polymerase chain reaction (qRT-PCR). A total of 448 DEGs and 186 DEGs were identified on postnatal day 7 and 21, respectively. GO analysis revealed that the DEGs on postnatal day 7 mainly participated in the biological functions of cell growth and proliferation, and the DEGs on postnatal day 21 mainly participated in ion transport/activity. KEGG enrichment analysis showed that the DEGs on postnatal day 7 were mainly enriched in the cell cycle, cytokine-cytokine receptor interactions, hypertrophic cardiomyopathy, and the p53 signaling pathway, while the DEGs on postnatal day 21 were mainly enriched in neuroactive ligand-receptor interactions, the calcium signaling pathway, retinol metabolism, and axon guidance. The qRT-PCR results were consistent with the RNA sequencing data. The DEGs may affect the growth of liver in early postnatal period while may affect ion transport/activity in late postnatal period.

A newly isolated intestinal bacterium involved in the C-ring cleavage of flavan-3-ol monomers and the antioxidant activity of the metabolites.

Flavan-3-ols are an important class of secondary metabolites in many plants. Their bioavailability and bioactivity are largely determined by the metabolism of intestinal microbiota. However, little is known about the intestinal bacteria involved in the metabolism of flavan-3-ols and the activities of the metabolites. C-ring cleavage is the initial and key step in the metabolism of flavan-3-ol monomers. Here, we isolated a strain from porcine cecum content, which is capable of cleaving the heterocyclic C-ring to form 1-(3',4'-dihydroxyphenyl)-3-(2'',4'',6''-trihydroxyphenyl)propan-2-ol from (+)-catechin and (-)-epicatechin, and 1-(3',4',5'-trihydroxyphenyl)-3-(2'',4'',6''-trihydroxyphenyl) propan-2-ol from (-)-epigallocatechin. The strain was identified as Streptococcus pasteurianus (Streptococcus gallolyticus subsp. Pasteurianus, designated as F32-1) based on 16S rDNA similarity and MALDI-TOF-MS identification. The formation of the C-ring cleavage structural unit by the F32-1 strain enhanced the chemical antioxidant ability and altered the cellular antioxidant activity of (+)-catechin, (-)-epicatechin and (-)-epigallocatechin. Overall, in this study we isolated a new intestinal bacterium involved in the C-ring cleavage of flavan-3-ol monomers and elucidated the bioactivity of their metabolites.