Lactylated Apolipoprotein C-II Induces Immunotherapy Resistance by Promoting Extracellular Lipolysis.

Mortality rates due to lung cancer are high worldwide. Although PD-1 and PD-L1 immune checkpoint inhibitors boost the survival of patients with non-small-cell lung cancer (NSCLC), resistance often arises. The Warburg Effect, which causes lactate build-up and potential lysine-lactylation (Kla), links immune dysfunction to tumor metabolism. The role of non-histone Kla in tumor immune microenvironment and immunotherapy remains to be clarified. Here, global lactylome profiling and metabolomic analyses of samples from patients with NSCLC is conducted. By combining multi-omics analysis with in vitro and in vivo validation, that intracellular lactate promotes extracellular lipolysis through lactyl-APOC2 is revealed. Mechanistically, lactate enhances APOC2 lactylation at K70, stabilizing it and resulting in FFA release, regulatory T cell accumulation, immunotherapy resistance, and metastasis. Moreover, the anti-APOC2K70-lac antibody that sensitized anti-PD-1 therapy in vivo is developed. This findings highlight the potential of anti lactyl-APOC2-K70 approach as a new combination therapy for sensitizing immunotherapeutic responses.

Association between pretreatment emotional distress and immune checkpoint inhibitor response in non-small-cell lung cancer.

Emotional distress (ED), commonly characterized by symptoms of depression and/or anxiety, is prevalent in patients with cancer. Preclinical studies suggest that ED can impair antitumor immune responses, but few clinical studies have explored its relationship with response to immune checkpoint inhibitors (ICIs). Here we report results from cohort 1 of the prospective observational STRESS-LUNG study, which investigated the association between ED and clinical efficacy of first-line treatment of ICIs in patients with advanced non-small-cell lung cancer. ED was assessed by Patient Health Questionnaire-9 and Generalized Anxiety Disorder 7-item scale. The study included 227 patients with 111 (48.9%) exhibiting ED who presented depression (Patient Health Questionnaire-9 score ≥5) and/or anxiety (Generalized Anxiety Disorder 7-item score ≥5) symptoms at baseline. On the primary endpoint analysis, patients with baseline ED exhibited a significantly shorter median progression-free survival compared with those without ED (7.9 months versus 15.5 months, hazard ratio 1.73, 95% confidence interval 1.23 to 2.43, P = 0.002). On the secondary endpoint analysis, ED was associated with lower objective response rate (46.8% versus 62.1%, odds ratio 0.54, P = 0.022), reduced 2-year overall survival rate of 46.5% versus 64.9% (hazard ratio for death 1.82, 95% confidence interval 1.12 to 2.97, P = 0.016) and detriments in quality of life. The exploratory analysis indicated that the ED group showed elevated blood cortisol levels, which was associated with adverse survival outcomes. This study suggests that there is an association between ED and worse clinical outcomes in patients with advanced non-small-cell lung cancer treated with ICIs, highlighting the potential significance of addressing ED in cancer management. ClinicalTrials.gov registration: NCT05477979 .

Chemical Constituents of the Fruits of Cornus Officinalis and Evaluation of their Neuroprotective Activity.

The phytochemical investigation of the fruits of Cornus officinalis yielded a new phenolic acid derivative, neophenolic acid A (1), and a novel flavonoid glycoside, (2R)-naringenin-7-O-ß-(6''-galloyl-glucopyranoside) (2 a), along with six known flavonoid glycosides (2 b-7). Their structures were determined by 1D, 2D NMR and HRESIMS data. The absolute configuration of 1 was established by ECD analysis. Compounds 1- 7 were evaluated for their neuroprotective activities against corticosterone (CORT)-induced injury in PC-12 cells. Compounds 1, 2 a, 2 b, 5, and 6 exhibited neuroprotective activities against CORT-induced neurotoxicity in PC-12 cells. The underlying mechanism study suggested that compounds 1, 2 a, 2 b, 5, and 6 were able to attenuate CORT-induced apoptosis and damage, increase the levels of MMP and decrease Ca2+ inward flow in PC-12 cells.

The clinical characteristics, gene mutations and outcomes of myelodysplastic syndromes with diabetes mellitus.

PURPOSE: Diabetes mellitus (DM) is the second most common comorbidity in myelodysplastic syndromes (MDS). The purpose of the study was to investigate the clinical characteristics of MDS patients with DM. METHODS: A retrospective analysis was performed on the clinical data of 890 MDS patients with or without DM. Clinical data, including genetic changes, overall survival (OS), leukemia-free survival (LFS) and infection, were analyzed. RESULTS: Among 890 patients, 184 (20.7%) had DM. TET2 and SF3B1 mutations occurred more frequently in the DM group than those in the non-DM group (p = 0.0092 and p = 0.0004, respectively). Besides, DM was an independent risk factor for infection (HR 2.135 CI 1.451-3.110, p = 0.000) in MDS. Compared to non-DM patients, MDS patients with DM had poor OS and LFS (p = 0.0002 and p = 0.0017, respectively), especially in the lower-risk group. While in multivariate analysis, DM did not retain its prognostic significance and the prognostic significance of infection was maintained (HR 2.488 CI 1.749-3.538, p = 0.000). CONCLUSIONS: MDS patients with DM have an inferior prognosis which may due to higher infection incidence, with TET2 and SF3B1 mutations being more frequent in those cases.

ROBO1 deficiency impairs HSPC homeostasis and erythropoiesis via CDC42 and predicts poor prognosis in MDS.

Myelodysplastic syndrome (MDS) is a group of clonal hematopoietic neoplasms originating from hematopoietic stem progenitor cells (HSPCs). We previously identified frequent roundabout guidance receptor 1 (ROBO1) mutations in patients with MDS, while the exact role of ROBO1 in hematopoiesis remains poorly delineated. Here, we report that ROBO1 deficiency confers MDS-like disease with anemia and multilineage dysplasia in mice and predicts poor prognosis in patients with MDS. More specifically, Robo1 deficiency impairs HSPC homeostasis and disrupts HSPC pool, especially the reduction of megakaryocyte erythroid progenitors, which causes a blockage in the early stages of erythropoiesis in mice. Mechanistically, transcriptional profiling indicates that Cdc42, a member of the Rho-guanosine triphosphatase family, acts as a downstream target gene for Robo1 in HSPCs. Overexpression of Cdc42 partially restores the self-renewal and erythropoiesis of HSPCs in Robo1-deficient mice. Collectively, our result implicates the essential role of ROBO1 in maintaining HSPC homeostasis and erythropoiesis via CDC42.

Cuproptosis-related molecular patterns and gene (ATP7A) in hepatocellular carcinoma and their relationships with tumor immune microenvironment and clinical features.

BACKGROUND: Cuproptosis has been studied in various aspects as a new form of cell death. AIMS: We hope to explore the molecular patterns and genes related to cuproptosis in evaluating and predicting the prognosis of hepatocellular carcinoma (HCC), as well as the impact of tumor immune microenvironment. METHODS AND RESULTS: Sixteen cuproptosis related gene (CRGs) and cuproptosis related molecular and gene characteristics were comprehensively analyzed from 492 HCC samples. Cuproptosis related molecular patterns were generated by consensus clustering algorithm, including cuproptosis clusters, cuproptosis gene clusters (CGC) and cuproptosis score (CS). The characteristics of tumor microenvironment (TME) and tumor immune cells were described by the ssGSEA and ESTIMATE algorithms. Cuproptosis score was established to assess the clinical characteristics, prognostic and immunotherapy. The role and mechanism of CRG (ATP7A) in HCC, as well as its relationship with TME and immune checkpoints, have been further explored. The results of somatic mutation, copy number variations (CNV), and CRGs expression in HCC suggested the CRGs might participate in the HCC oncogenesis. The cuproptosis clusters were closely related to the clinical pathological characteristics, biological processes, and prognosis of HCC. The three CGC was revealed to be consistent with the three immune infiltration characterizations, including immune-high, immune-mid, and immune-low subtypes. Higher CS was characterized by decreased TMB, activated immunity, higher immune cell proportion score (IPS) and better overall survival (OS), which indicated higher CS was immune-high type and with better treatment effect and prognosis. The ATP7A had the highest hazard ratio (HR = 1.465, p < .001), was high expression in HCC tissues and with a shorter 5-year OS. Knocking down ATP7A could enhance intracellular copper concentration, cause a decrease in DLAT expression, and induce cuproptosis and inhibit cell proliferation and migration. ATP7A was also positively correlated with most cancer immune cells and immune checkpoints. CONCLUSION: Taken together, this research revealed the cuproptosis related molecular patterns and genes associated with the clinical pathological characteristics, TME phenotype and prognosis of HCC. The CS will further deepen our understanding of the TME characteristics of HCC, and the involvement of ATP7A in cuproptosis will provide new ideas for predicting HCC prognosis and immunotherapy.

Understanding the Molecular Mechanisms of Polyphenol Inhibition of Amyloid ß Aggregation.

Alzheimer's disease (AD) is highly associated with self-aggregation of amyloid ß (Aß) proteins into fibrils. Inhibition of Aß aggregation by polyphenols is one of the major therapeutic strategies for AD. Among them, four polyphenols (brazilin, resveratrol, hematoxylin, and rosmarinic acid) have been reported to be effective at inhibiting Aß aggregation, but the inhibition mechanisms are still unclear. In this work, these four polyphenols were selected to explore their interactions with the Aß17-42 pentamer by molecular dynamics simulation. All four polyphenols can bind to the pentamer tightly but prefer different binding sites. Conversion of the ß-sheet to the random coil, fewer interchain hydrogen bonds, and weaker salt bridges were observed after binding. Interestingly, different Aß17-42 pentamer destabilizing mechanisms for resveratrol and hematoxylin were found. Resveratrol inserts into the hydrophobic core of the pentamer by forming hydrogen bonds with Asp23 and Lys28, while hematoxylin prefers to bind beside chain A of the pentamer, which leads to ß-sheet offset and dissociation of the ß1 sheet of chain E. This work reveals the interactions between the Aß17-42 pentamer and four polyphenols and discusses the relationship between inhibitor structures and their inhibition mechanisms, which also provides useful guidance for screening effective Aß aggregation inhibitors and drug design against AD.

A Unique G-Quadruplex Aptamer: A Novel Approach for Cancer Cell Recognition, Cell Membrane Visualization, and RSV Infection Detection.

Surface staining has emerged as a rapid technique for applying external stains to trace cellular identities in diverse populations. In this study, we developed a distinctive aptamer with selective binding to cell surface nucleolin (NCL), bypassing cytoplasmic internalization. Conjugation of the aptamer with a FAM group facilitated NCL visualization on live cell surfaces with laser confocal microscopy. To validate the aptamer-NCL interaction, we employed various methods, including the surface plasmon resonance, IHC-based flow cytometry, and electrophoretic mobility shift assay. The G-quadruplex formations created by aptamers were confirmed with a nuclear magnetic resonance and an electrophoretic mobility shift assay utilizing BG4, a G-quadruplex-specific antibody. Furthermore, the aptamer exhibited discriminatory potential in distinguishing between cancerous and normal cells using flow cytometry. Notably, it functioned as a dynamic probe, allowing real-time monitoring of heightened NCL expression triggered by a respiratory syncytial virus (RSV) on normal cell surfaces. This effect was subsequently counteracted with dsRNA transfection and suppressed the NCL expression; thus, emphasizing the dynamic attributes of the probe. These collective findings highlight the robust versatility of our aptamer as a powerful tool for imaging cell surfaces, holding promising implications for cancer cell identification and the detection of RSV infections.

Exosome from adipose-derived mesenchymal stem cells attenuates scar formation through microRNA-181a/SIRT1 axis.

Pathological scarring is the greatest challenge after injury. Exosome from adipose-derived mesenchymal stem cells has been reported effective to improve hypertrophic scar. This study focused on the possible mechanisms during this process. Exosomes from adipose-derived mesenchymal stem cells were extracted first. Hypertrophic scar tissue and paired normal skin tissue were collected from patients. Mice skin incision model and fibroblasts model were established. TGF-ß1 was used to stimulate fibroblasts to myofibroblasts transdifferentiation. It was found that exosomes injection could decrease collagen sediment after wound healing. During which, the expression of microRNA-181a decreased. Further, we found that expression of microRNA-181a in scar tissue was higher than in normal skin. Then hypertrophic scar-derived fibroblasts were used for in vitro study. It was found that similar to the use of exosomes, microRNA-181a inhibitor decreased the expression of collagen and α-SMA. While microRNA-181a mimics suppressed the effects of exosomes. During fibroblast to myofibroblast trans-differentiation, level of microRNA-181a well as levels of scar-related molecules also decreased with the use of exosomes and vice versa. SIRT1 was confirmed one of the downstream targets of microRNA-181a. Suppression of SIRT1 led to diminished effects of exosomes in hypertrophic scar derived fibroblasts. In mice skin incision model, injection of SIRT1 inhibitor led to increased collagen synthesis. In conclusion, exosomes from Adipose-derived mesenchymal stem cells are promising to antagonize scarring through the regulation of microRNA-181a/SIRT1 axis.

Unveiling the role of G-quadruplex structure in promoter region: Regulation of ABCA1 expression in macrophages possibly via NONO protein recruitment.

ABCA1 has been found to be critical for cholesterol efflux in macrophages. Understanding the mechanism regulating ABCA1 expression is important for the prevention and treatment of atherosclerosis. In the present study, a G-quadruplex (G4) structure was identified in the ABCA1 promoter region. This G4 was shown to be essential for ABCA1 transcription. Stabilizing the G4 by ligands surprisingly upregulated ABCA1 expression in macrophages. Knocking out the G4 remarkably reduced ABCA1 expression, and abolished the increase of ABCA1 expression induced by the G4 ligand. By pull-down assays, the protein NONO was identified as an ABCA1 G4 binder. Overexpression or repression of NONO significantly induced upregulation and downregulation of ABCA1 expression, respectively. ChIP and EMSA experiments showed that the G4 ligand promoted the binding between the ABCA1 G4 and NONO, which led to more recruitment of NONO to the promoter region and enhanced ABCA1 transcription. Finally, the G4 ligand was shown to significantly reduce the accumulation of cholesterol in macrophages. This study showed a new insight into the regulation of gene expression by G4, and provided a new molecular mechanism regulating ABCA1 expression in macrophages. Furthermore, the study showed a possible novel application of the G4 ligand: preventing and treating atherosclerosis.

Exploiting Broad-Spectrum Chimeric Lysin to Cooperate with Mupirocin against Staphylococcus aureus-Induced Skin Infections and Delay the Development of Mupirocin Resistance.

Staphylococcus aureus often leads to severe skin infections. However, S. aureus is facing a crisis of antibiotic resistance. The combination of phage and antibiotics is effective for drug-resistant S. aureus infections. Therefore, it is worth exploiting novel antibacterial agents to cooperate with antibiotics against S. aureus infections. Herein, a novel chimeric lysin ClyQ was constructed, which was composed of a cysteine- and histidine-dependent amidohydrolase/peptidase (CHAP) catalytic domain from S. aureus phage lysin LysGH15 and cell wall-binding domain (CBD) from Enterococcus faecalis phage lysin PlyV12. ClyQ had an exceptionally broad host range targeting streptococci, staphylococci, E. faecalis, and E. rhusiopathiae. ClyQ combined with mupirocin (2.64 log reduction) was more effective at treating S. aureus skin infections than ClyQ (0.46 log reduction) and mupirocin (2.23 log reduction) alone. Of equal importance, none of S. aureus ATCC 29213 or S3 exposed to ClyQ developed resistance, and the combination of ClyQ and mupirocin delayed the development of mupirocin resistance. Collectively, chimeric lysin ClyQ enriches the reservoirs for treating S. aureus infections. Our findings may provide a way to alleviate the current antibiotic resistance crisis. IMPORTANCE Staphylococcus aureus, as an Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species (ESKAPE) pathogen, can escape the elimination of existing antibiotics. At present, phages and phage lysins against S. aureus infections are considered alternative antibacterial agents. However, the development of broad-spectrum chimeric phage lysins to cooperate with antibiotics against S. aureus infections remains at its initial stage. In this study, we found that the broad-host-range chimeric lysin ClyQ can synergize with mupirocin to treat S. aureus skin infections. Furthermore, the development of S. aureus resistance to mupirocin is delayed by the combination of ClyQ and mupirocin in vitro. Our results bring research attention toward the development of chimeric lysin that cooperates with antibiotics to overcome bacterial infections.

Collagen I-DDR1 signaling promotes hepatocellular carcinoma cell stemness via Hippo signaling repression.

Cancer stem cells (CSCs) are a minority population of cancer cells with stemness and multiple differentiation potentials, leading to cancer progression and therapeutic resistance. However, the concrete mechanism of CSCs in hepatocellular carcinoma (HCC) remains obscure. We found that in advanced HCC tissues, collagen I was upregulated, which is consistent with the expression of its receptor DDR1. Accordingly, high collagen I levels accompanied by high DDR1 expression are associated with poor prognoses in patients with HCC. Collagen I-induced DDR1 activation enhanced HCC cell stemness in vitro and in vivo. Mechanistically, DDR1 interacts with CD44, which acts as a co-receptor that amplifies collagen I-induced DDR1 signaling, and collagen I-DDR1 signaling antagonized Hippo signaling by facilitating the recruitment of PP2AA to MST1, leading to exaggerated YAP activation. The combined inhibition of DDR1 and YAP synergistically abrogated HCC cell stemness in vitro and tumorigenesis in vivo. A radiomic model based on T2 weighted images can noninvasively predict collagen I expression. These findings reveal the molecular basis of collagen I-DDR1 signaling inhibiting Hippo signaling and highlight the role of CD44/DDR1/YAP axis in promoting cancer cell stemness, suggesting that DDR1 and YAP may serve as novel prognostic biomarkers and therapeutic targets in HCC.

Effects of sericin on oxidative stress and PI3K/AKT/mTOR signal pathway in cryopreserved mice ovarian tissue.

Ovarian tissue cryopreservation is an effective fertility protective strategy for preadolescent female cancer patients, whose tumor treatment cannot be delayed. In the present study, the effects of sericin, as an antioxidant, on mice ovarian tissue freezing and thawing were investigated. Mice ovarian tissues were cryopreserved and thawed in medium containing 0.5% or 1%sericin (w/v), and 0.1 mM melatonin. Then, the follicular morphology was observed. The levels of antioxidant enzymes were determined, including glutathione (GSH), glutathione peroxidase (GSH-Px), total superoxide dismutase (T-SOD), total antioxidant capacity (T-AOC) and catalase (CAT). Moreover, the levels of nitric oxide (NO), malondialdehyde (MDA) and lactate dehydrogenase (LDH) were also tested. Besides, apoptosis-related proteins Bcl-2 and Bax were determined. Our results showed that 1% sericin maintained follicular morphology, inhibited apoptosis, decreased MDA and NO levels, and boosted endogenous antioxidant enzyme levels, while had no significant effect on LDH levels. Furthermore, these effects may be related with the activation of the phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of Rapamycin (mTOR) signaling pathway, as demonstrated by increased PI3K, p-AKT and mTOR levels. These findings demonstrate that 1% sericin may reduce oxidative stress and protect ovarian tissues during freezing and thawing via PI3K/AKT/mTOR signaling pathway.

Ileal adenocarcinoma in a young pregnant woman: A rare case report.

Primary intestinal malignancies account for only 1%-3% of all malignant gastrointestinal tumors. Adenocarcinomas are uncommonly located in the ileum. Ileal adenocarcinoma (IA) is rare and difficult to diagnose because of its location. IA is common in older men and rare in young pregnant women. A 23-year-old pregnant woman was hospitalized several times for repeated vomiting and abdominal pain. Her symptoms were relieved after symptomatic treatment. She exhibited no typical manifestations of intestinal obstruction, such as abdominal distension, difficulty passing gas and defecation. Unfortunately, she was misdiagnosed with acute gastroenteritis. On the second day after delivery, the patient stopped passing gas and computed tomography (CT) revealed an intestinal obstruction. She was treated as paralytic ileus. However, in view of failed conservative management, she was decided for an exploratory laparotomy. A malignant ileal tumor 5cm from the ileocecal valve was found incidentally and was surgically excised accompanied with End-to-side anastomosis of ileal and transverse colon. The operation lasted 195 minutes. Pathological examination revealed an IA. Pregnant woman who experience symptoms of intestinal obstruction should be alert to the possibility of malignancy in the small intestine. IA is an insidious tumor in pregnant women. An "IA triad" can be defined as refractory vomiting, vague abdominal pain, and weight loss (or inadequate weight gain in pregnant women). Pregnant women with an IA triad should undergo investigation with endoscopy or, if necessary, magnetic resonance imaging (MRI).

A rapid approach to capture the potential bioactive compounds from Rhizoma Drynariae, utilizing disease-associated mutation in calcium sensing receptor to alter the binding affinity for agonists.

Rhizoma Drynariae (RD) was used clinically to treat osteoporosis in China due to stimulating bone formation and inhibiting bone resorption, however, the bioactive constituents with the dual effect on bone are still unknown exactly. Disease-causing mutations in calcium sensing receptor (CaSR) can alter parathyroid hormone secretion and affect Ca2+ release from bone and Ca2+ reabsorption from kidney, which gives an indication that CaSR is a potential target for developing therapeutics to manage osteoporosis. Herein, a chromatographic approach was established, by immobilizing the mutant CaSR onto the surface of silica gels as stationary phase in a one-step procedure and then adding the different amino acids into mobile phase as competitors, for exploring the binding features of the known agonists and further screening ligands from RD. The mutant CaSR-coated column was prepared rapidly without the complicated purification and separation of the receptor, which had the large capacity of 13.1 mg CaSR /g silica gels and kept a good stability and specificity for at least 35 days. The CaSR mutation can weaken the binding affinities for three agonists, and the largest decreases occurred on the mutational site Thr151Met for neomycin, on the two sites of Asn118Lys and Glu191Lys for gentamicin-C, and on the site Phe612Ser for kanamycin, which gained new insights into their structure-function relationship. The potential bioactive compounds from RD were screened using the mutant CaSR-coated column and were recognized as coumaric acid 4-O-ß-D-glucopyranoside, caffeic acid, and naringin using UPLC-MS. Among them, naringin targeting CaSR gives a possible explanation that RD could manage osteoporosis. These results indicated that, such a rapid and simple method, utilizing disease-associated mutation in CaSR to alter the binding affinity for agonists, can be applied in capturing the potential bioactive compounds efficiently from complex matrices like herb medicines.

The use of carbon monoxide breath test to detect the effect of iron overload on erythrocyte lifespan in MDS.

Objective: To investigate the effect of iron overload (IO) on red blood cell (RBC) lifespan in MDS patients with the use of carbon monoxide breath test. Methods: The red blood cell lifespan of 93 patients with myelodysplastic syndrome (MDS) and 22 healthy volunteers in the control group were measured by alveolar gas carbon monoxide (CO) assay, with the detection of liver iron concentration, iron metabolism index, erythropoietin (EPO) concentration, peripheral blood inflammatory cytokines, etc. The MDS patients were divided into the severe IO group, mild IO group and non IO group according to liver iron concentration. The effect of IO on RBC lifespan was analyzed in MDS patients. Results: The RBC lifespan of MDS patients in the severe IO group was significantly lower than that in the mild IO group (p<0.05), while the RBC life span in the mild IO group was significantly lower than that in the non IO group (p<0.05). The expression of inflammatory cytokines in the severe IO group was significantly higher than that of the mild and non IO groups. After receiving iron removal treatment(ICT), the expression of inflammatory cytokines was decreased significantly, and the RBC lifespan was significantly prolonged (p<0.05).Besides, liver iron concentration was significantly positively correlated with EPO concentration, while EPO concentration was significantly negatively correlated with RBC lifespan, especially in the MDS-RS subgroup. The RBC lifespan in the EPO>1000 group was significantly lower than that in the EPO<1000 group. Conclusion: IO can shorten RBC lifespan in MDS patients, which may be result from the increase of endogenous EPO and the over-expression of inflammatory cytokines. After ICT, the ineffective hematopoiesis caused by increased EPO may reduced and the decrease of inflammatory cytokine may significantly prolong the RBC lifespan in MDS patients.

One-stage revision arthroplasty in a patient with ochronotic arthropathy accompanied by joint infection: A case report.

BACKGROUND: Ochronotic arthropathy (OcA) is a rare disease, which is caused by the accumulation of homogentisic acid in the joint. Patients with OcA have obvious joint pain and the disease progresses rapidly, eventually resulting in disability. Arthroplasty is an efficacious treatment in patients with OcA. However, when OcA patients have joint infection, is joint replacement an option? In the present report, we performed total knee arthroplasty in a patient with OcA and knee infection under the guidance of one-stage revision theory. CASE SUMMARY: A 64-year-old male was referred to our hospital due to severe left knee pain with limited mobility for 2 years. On physical examination, the patient was found to have dark brown pigmentation of the sclera and auricle. Laboratory test results showed elevations in C-reactive protein level (65.79 mg/L) and erythrocyte sedimentation rate (90.00 mm/h). The patient underwent debridement of the left knee joint, during which the cartilage surface of the knee joint was found to be black-brown in color. Bacterial culture of synovial fluid revealed Achromobacter xylosoxidans. We then carried out arthroplasty under the guidance of the theory of one-stage revision. After surgery, the patient's left knee joint pain disappeared and function recovered without joint infection. CONCLUSION: OcA accompanied by joint infection is rare. One-stage revision arthroplasty may be a treatment option for this disease.

Identification of a cytochrome P450 from Tripterygium hypoglaucum (Levl.) Hutch that catalyzes polpunonic acid formation in celastrol biosynthesis.

Tripterygium hypoglaucum (Levl.) Hutch, a traditional Chinese medicinal herb with a long history of use, is widely distributed in China. One of its main active components, celastrol, has great potential to be developed into anti-cancer and anti-obesity drugs. Although it exhibits strong pharmacological activities, there is a lack of sustainable sources of celastrol and its derivatives, making it crucial to develop novel sources of these drugs through synthetic biology. The key step in the biosynthesis of celastrol is considered to be the cyclization of 2,3-oxidosqualene into friedelin under the catalysis of 2,3-oxidosqualene cyclases. Friedelin was speculated to be oxidized into celastrol by cytochrome P450 oxidases (CYP450s). Here, we reported a cytochrome P450 ThCYP712K1 from Tripterygium hypoglaucum (Levl.) Hutch that catalyzed the oxidation of friedelin into polpuonic acid when heterologously expressed in yeast. Through substrate supplementation and in vitro enzyme analysis, ThCYP712K1 was further proven to catalyze the oxidation of friedelin at the C-29 position to produce polpunonic acid, which is considered a vital step in the biosynthesis of celastrol, and will lay a foundation for further analysis of its biosynthetic pathway.