Ubiquitin-induced RNF168 condensation promotes DNA double-strand break repair.

Rapid accumulation of repair factors at DNA double-strand breaks (DSBs) is essential for DSB repair. Several factors involved in DSB repair have been found undergoing liquid-liquid phase separation (LLPS) at DSB sites to facilitate DNA repair. RNF168, a RING-type E3 ubiquitin ligase, catalyzes H2A.X ubiquitination for recruiting DNA repair factors. Yet, whether RNF168 undergoes LLPS at DSB sites remains unclear. Here, we identified K63-linked polyubiquitin-triggered RNF168 condensation which further promoted RNF168-mediated DSB repair. RNF168 formed liquid-like condensates upon irradiation in the nucleus while purified RNF168 protein also condensed in vitro. An intrinsically disordered region containing amino acids 460-550 was identified as the essential domain for RNF168 condensation. Interestingly, LLPS of RNF168 was significantly enhanced by K63-linked polyubiquitin chains, and LLPS largely enhanced the RNF168-mediated H2A.X ubiquitination, suggesting a positive feedback loop to facilitate RNF168 rapid accumulation and its catalytic activity. Functionally, LLPS deficiency of RNF168 resulted in delayed recruitment of 53BP1 and BRCA1 and subsequent impairment in DSB repair. Taken together, our finding demonstrates the pivotal effect of LLPS in RNF168-mediated DSB repair.

Comprehending the inhibition mechanism of indole-based bis-acylhydrazone compounds on α-glucosidase: Spectral and theoretical approaches.

Indole-based bis-acylhydrazone compounds can inhibit the activity of α-glucosidase and control the concentration of blood glucose. In this paper, the characteristics of three indole-based bis-acylhydrazone compounds with different inhibitory activities of α-glucosidase as well as the interaction with α-glucosidase were studied by experiments and computational simulation techniques. Enzyme kinetic and spectral experiments showed that the indole-based bis-acylhydrazone compounds were able to inhibit enzyme activity through mixed inhibition dominated by competitive inhibition, and during the binding reaction, indole-based bis-acylhydrazone compounds can quench the intrinsic fluorescence of α-glucosidase through static quenching and an aggregation of the indole-based bis-acylhydrazone with α-glucosidase produces a stable complex with a molar ratio of 1:1, and the combination of indole-based bis-acylhydrazone compounds could lead to slight change in the conformation of α-glucosidase. The theoretical simulation demonstrated that the stability of the complex systems was positively correlated with the inhibitory activity of indole-based bis-acylhydrazone compounds, and the indole-based bis-acylhydrazone compounds occupied the active site in the multi-ligand system, resulting in a significant decrease in the binding ability of starch to active amino acids. These results suggested that indole-based bis-acylhydrazone compound was expected to be a new type of α-glucosidase inhibitor.

Glutathione determines chronic myeloid leukemia vulnerability to an inhibitor of CMPK and TMPK.

Bcr-Abl transformation leads to chronic myeloid leukemia (CML). The acquirement of T315I mutation causes tyrosine kinase inhibitors (TKI) resistance. This study develops a compound, JMF4073, inhibiting thymidylate (TMP) and cytidylate (CMP) kinases, aiming for a new therapy against TKI-resistant CML. In vitro and in vivo treatment of JMF4073 eliminates WT-Bcr-Abl-32D CML cells. However, T315I-Bcr-Abl-32D cells are less vulnerable to JMF4073. Evidence is presented that ATF4-mediated upregulation of GSH causes T315I-Bcr-Abl-32D cells to be less sensitive to JMF4073. Reducing GSH biosynthesis generates replication stress in T315I-Bcr-Abl-32D cells that require dTTP/dCTP synthesis for survival, thus enabling JMF4073 susceptibility. It further shows that the levels of ATF4 and GSH in several human CML blast-crisis cell lines are inversely correlated with JMF4073 sensitivity, and the combinatory treatment of JMF4073 with GSH reducing agent leads to synthetic lethality in these CML blast-crisis lines. Altogether, the investigation indicates an alternative option in CML therapy.

Protein Profiles and Novel Molecular Biomarkers of Schizophrenia Based on 4D-DIA Proteomics.

Schizophrenia is a severe psychological disorder. The current diagnosis mainly relies on clinical symptoms and lacks laboratory evidence, which makes it very difficult to make an accurate diagnosis especially at an early stage. Plasma protein profiles of schizophrenia patients were obtained and compared with healthy controls using 4D-DIA proteomics technology. Furthermore, 79 DEPs were identified between schizophrenia and healthy controls. GO functional analysis indicated that DEPs were predominantly associated with responses to toxic substances and platelet aggregation, suggesting the presence of metabolic and immune dysregulation in patients with schizophrenia. KEGG pathway enrichment analysis revealed that DEPs were primarily enriched in the chemokine signaling pathway and cytokine receptor interactions. A diagnostic model was ultimately established, comprising three proteins, namely, PFN1, GAPDH and ACTBL2. This model demonstrated an AUC value of 0.972, indicating its effectiveness in accurately identifying schizophrenia. PFN1, GAPDH and ACTBL2 exhibit potential as biomarkers for the early detection of schizophrenia. The findings of our studies provide novel insights into the laboratory-based diagnosis of schizophrenia.

[Application of micro-computed tomography (µCT)in quantifying xylem vessels of broadleaved trees]. / 计算机显微断层扫描技术(µCT)åœ¨é‡åŒ–é˜”å¶æ ‘ç§å¯¼ç®¡ä¸­çš„åº”ç”¨.

Quantitative analysis of vessel characteristics at the cellular scale is of great significance for understan-ding plant adaptation strategies to environment. The direct grinding combined with stereo-microscope imaging is one of the main approaches to examine the anatomical structure of xylem (conifer tracheid and hardwood vessel) wood structure, which inevitably damages xylem cells, hindering the accurate understanding of anatomical structures. In this study, we applied X-ray micro-computed tomography (µCT) and stereo-microscope technology to quantitatively measure the diameter and area of vessels of seven Canadian broadleaved tree species (Acer saccharum, Betula papyrifera, Fraxinus americana, Ostrya virginiana, Populus grandidentata, Quercus rubra, and Carya cordiformis). We fitted the results by linear model and tested the feasibility of µCT technology in quantifying the vessel size of broadleaved species. We found that the results of the two methods for measuring vessel size were highly similar (R2=0.98). The goodness of fit of the vessel diameter results measured by the two methods for the ring-porous wood species (C. cordiformis, R2=0.98; F. americana, R2=0.96; Q. rubra, R2=0.99) was higher than that of the diffuse-porous wood species (B. papyrifera, R2=0.88; O. virginiana, R2=0.73; A. saccharum, R2=0.68; P. grandiden-tata, R2=0.88). The goodness of fit of small vessels (diameter≤200 µm, R2=0.94) measured by the two methods was higher than that of large vessels (diameter>200 µm, R2=0.92). Thus, the µCT technique provided a new non-destructive detection method for quantifying xylem vessels of broadleaved tree species.

[FeIIICl(TMPPH2)][FeIIICl4]2: A Stand-Alone Molecular Nanomedicine That Induces High Cytotoxicity by Ferroptosis.

Developing clinically meaningful nanomedicines for cancer therapy requires the drugs to be effective, safe, simple, cheap, and easy to store. In the present work, we report that a simple cationic Fe(III)-rich salt of [FeIIICl(TMPPH2)][FeIIICl4]2 (Fe-TMPP) exhibits a superior anticancer performance on a broad spectrum of cancer cell lines, including breast, colorectal cancer, liver, pancreatic, prostate, and gastric cancers, with half maximal inhibitory concentration (IC50) values in the range of 0.098-3.97 µM (0.066-2.68 µg mL-1), comparable to the best-reported medicines. Fe-TMPP can form stand-alone nanoparticles in water without the need for extra surface modification or organic-solvent-assisted antisolvent precipitation. Critically, Fe-TMPP is TME-responsive (TME = tumor microenvironment), and can only elicit its function in the TME with overexpressed H2O2, converting H2O2 to the cytotoxic •OH to oxidize the phospholipid of the cancer cell membrane, causing ferroptosis, a programmed cell death process of cancer cells.

CS/PVP Hydrogel-Based Nanocapillary for Monitoring Bacterial Growth and Rapid Antibiotic Susceptibility Testing.

Infection with drug-resistant bacteria poses a significant threat to human health. Judicious use of antibiotics could reduce the likelihood of bacterial resistance, which can be evaluated through antibiotic susceptibility testing (AST). This paper focuses on the application of a needle-like nanocapillary tip filled with chitosan (CS)/polyethylene pyrrolidone (PVP) hydrogel based on its specific pH-sensitive properties. The gel-filled nanocapillary has the potential to be used for electrical pH detection with a sensitivity of 3.06 nA/pH and a linear range from 7.3 to 4.3. Such sensitivity for pH measurement could be extended for monitoring of bacterial (such as Escherichia coli and Streptococcus salivarius) growth because of the relationship between pH and bacterial growth. Bacterial growth curves obtained using the hydrogel-filled nanocapillary showed good agreement with the OD600 method. Moreover, this device could be applied for rapid AST for tetracycline and norfloxacin on E. coli with minimum inhibitory concentrations of 2 and 0.125 µg/mL, respectively. This study expands the application of the hydrogel-based nanocapillary for bacterial research by monitoring changes in pH values.

Effects of melatonin on sperm quality, enzyme activity, antioxidant gene expression and fertility of cryopreserved bovine semen.

Melatonin (MLT) has strong antioxidant capacity and can reduce the damage caused by oxidative stress in sperm, but there is still little content in the field we have studied. In this study, we are committed to scientific research on adding melatonin to Belgian blue bull semen diluent for cryopreservation. Different concentrations (0, 0.1, 0.3, 0.5 or 0.7 mg/mL) of MLT were added diluent. Sperm kinetic parameters, enzyme activity, antioxidant gene expression and fertility were analyzed after thawing. The results showed that MLT concentration of 0.3 mg/mL exerted positive effects on post-thaw kinetic parameters. Compared with other groups, 0.3 mg/mL MLT treated sperm acrosome and plasma membrane integrity, catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) levels significantly increased. Meanwhile, the mRNA expression of antioxidant genes SOD2, CAT and GPx increased in the 0.3 mg/mL MLT treatment group, and the mRNA expression of apoptosis genes Caspase-3 and Bax were significantly reduced. In addition, in vitro fertilization (IVF) embryo cleavage, blastocyst rate and artificial insemination (AI) pregnancy rate were higher in 0.3 mg/mL MLT. Therefore, MLT showed cryoprotective capacity to the freezing diluent used for Belgian blue bull sperm during the process of freezing-thawing, and the optimal concentration of MLT for the frozen diluent was 0.3 mg/mL.

Dual-Mechanism Peptide SR25 has Broad Antimicrobial Activity and Potential Application for Healing Bacteria-infected Diabetic Wounds.

The rise of antibiotic resistance poses a significant public health crisis, particularly due to limited antimicrobial options for the treatment of infections with Gram-negative pathogens. Here, an antimicrobial peptide (AMP) SR25 is characterized, which effectively kills both Gram-negative and Gram-positive bacteria through a unique dual-targeting mechanism without detectable resistance. Meanwhile, an SR25-functionalized hydrogel is developed for the efficient treatment of infected diabetic wounds. SR25 is obtained through genome mining from an uncultured bovine enteric actinomycete named Nonomuraea Jilinensis sp. nov. Investigations reveal that SR25 has two independent cellular targets, disrupting bacterial membrane integrity and restraining the activity of succinate:quinone oxidoreductase (SQR). In a diabetic mice wound infection model, the SR25-incorporated hydrogel exhibits high efficacy against mixed infections of Escherichia coli (E. coli) and methicillin-resistant Staphylococcus aureus (MRSA), accelerating wound healing. Overall, these findings demonstrate the therapeutic potential of SR25 and highlight the value of mining drugs with multiple mechanisms from uncultured animal commensals for combating challenging bacterial pathogens.

CCDC50 mediates the clearance of protein aggregates to prevent cellular proteotoxicity.

Protein aggregation caused by the disruption of proteostasis will lead to cellular cytotoxicity and even cell death, which is implicated in multiple neurodegenerative diseases. The elimination of aggregated proteins is mediated by selective macroautophagy receptors, which is termed aggrephagy. However, the identity and redundancy of aggrephagy receptors in recognizing substrates remain largely unexplored. Here, we find that CCDC50, a highly expressed autophagy receptor in brain, is recruited to proteotoxic stresses-induced polyubiquitinated protein aggregates and ectopically expressed aggregation-prone proteins. CCDC50 recognizes and further clears these cytotoxic aggregates through autophagy. The ectopic expression of CCDC50 increases the tolerance to stress-induced proteotoxicity and hence improved cell survival in neuron cells, whereas CCDC50 deficiency caused accumulation of lipid deposits and polyubiquitinated protein conjugates in the brain of one-year-old mice. Our study illustrates how aggrephagy receptor CCDC50 combats proteotoxic stress for the benefit of neuronal cell survival, thus suggesting a protective role in neurotoxic proteinopathy.

p85α deficiency alleviates ischemia-reperfusion injury by promoting cardiomyocyte survival.

Myocardial ischemia-reperfusion (I/R) injury is a prevalent cause of myocardial injury, involving a series of interconnected pathophysiological processes. However, there is currently no clinical therapy for effectively mitigating myocardial I/R injury. Here, we show that p85α protein levels increase in response to I/R injury through a comprehensive analysis of cardiac proteomics, and confirm this in the I/R-injured murine heart and failing human myocardium. Genetic inhibition of p85α in mice activates the Akt-GSK3ß/Bcl-x(L) signaling pathway and ameliorates I/R-induced cardiac dysfunction, apoptosis, inflammation, and mitochondrial dysfunction. p85α silencing in cardiomyocytes alleviates hypoxia-reoxygenation (H/R) injury through activating the Akt-GSK3ß/Bcl-x(L) signaling pathway, while its overexpression exacerbates the damage. Mechanistically, the interaction between MG53 and p85α triggers the ubiquitination and degradation of p85α, consequently enhancing Akt phosphorylation and ultimately having cardioprotective effects. Collectively, our findings reveal that substantial reduction of p85α and subsequently activated Akt signaling have a protective effect against cardiac I/R injury, representing an important therapeutic strategy for mitigating myocardial damage.

Engineered endolysin of Klebsiella pneumoniae phage is a potent and broad-spectrum bactericidal agent against "ESKAPEE" pathogens.

The rise of antimicrobial resistance in ESKAPEE pathogens poses significant clinical challenges, especially in polymicrobial infections. Bacteriophage-derived endolysins offer promise in combating this crisis, but face practical hurdles. Our study focuses on engineering endolysins from a Klebsiella pneumoniae phage, fusing them with ApoE23 and COG133 peptides. We assessed the resulting chimeric proteins' bactericidal activity against ESKAPEE pathogens in vitro. ApoE23-Kp84B (CHU-1) reduced over 3 log units of CFU for A. baumannii, E. faecalis, K. pneumoniae within 1 h, while COG133-Kp84B (CHU-2) showed significant efficacy against S. aureus. COG133-L1-Kp84B, with a GS linker insertion in CHU-2, exhibited outstanding bactericidal activity against E. cloacae and P. aeruginosa. Scanning electron microscopy revealed alterations in bacterial morphology after treatment with engineered endolysins. Notably, CHU-1 demonstrated promising anti-biofilm and anti-persister cell activity against A. baumannii and E. faecalis but had limited efficacy in a bacteremia mouse model of their coinfection. Our findings advance the field of endolysin engineering, facilitating the customization of these proteins to target specific bacterial pathogens. This approach holds promise for the development of personalized therapies tailored to combat ESKAPEE infections effectively.

Efficacy of a single low dose of esketamine after childbirth for mothers with symptoms of prenatal depression: randomised clinical trial.

OBJECTIVE: To determine whether a single low dose of esketamine administered after childbirth reduces postpartum depression in mothers with prenatal depression. DESIGN: Randomised, double blind, placebo controlled trial with two parallel arms. SETTING: Five tertiary care hospitals in China, 19 June 2020 to 3 August 2022. PARTICIPANTS: 364 mothers aged ≥18 years who had at least mild prenatal depression as indicated by Edinburgh postnatal depression scale scores of ≥10 (range 0-30, with higher scores indicating worse depression) and who were admitted to hospital for delivery. INTERVENTIONS: Participants were randomly assigned 1:1 to receive either 0.2 mg/kg esketamine or placebo infused intravenously over 40 minutes after childbirth once the umbilical cord had been clamped. MAIN OUTCOME MEASURES: The primary outcome was prevalence of a major depressive episode at 42 days post partum, diagnosed using the mini-international neuropsychiatric interview. Secondary outcomes included the Edinburgh postnatal depression scale score at seven and 42 days post partum and the 17 item Hamilton depression rating scale score at 42 days post partum (range 0-52, with higher scores indicating worse depression). Adverse events were monitored until 24 hours after childbirth. RESULTS: A total of 364 mothers (mean age 31.8 (standard deviation 4.1) years) were enrolled and randomised. At 42 days post partum, a major depressive episode was observed in 6.7% (12/180) of participants in the esketamine group compared with 25.4% (46/181) in the placebo group (relative risk 0.26, 95% confidence interval (CI) 0.14 to 0.48; P<0.001). Edinburgh postnatal depression scale scores were lower in the esketamine group at seven days (median difference -3, 95% CI -4 to -2; P<0.001) and 42 days (-3, -4 to -2; P<0.001). Hamilton depression rating scale scores at 42 days post partum were also lower in the esketamine group (-4, -6 to -3; P<0.001). The overall incidence of neuropsychiatric adverse events was higher in the esketamine group (45.1% (82/182) v 22.0% (40/182); P<0.001); however, symptoms lasted less than a day and none required drug treatment. CONCLUSIONS: For mothers with prenatal depression, a single low dose of esketamine after childbirth decreases major depressive episodes at 42 days post partum by about three quarters. Neuropsychiatric symptoms were more frequent but transient and did not require drug intervention. TRIAL REGISTRATION: ClinicalTrials.gov NCT04414943.

Single-center retrospective study of the diagnostic value of double-balloon enteroscopy in Meckel's diverticulum with bleeding.

BACKGROUND: The study aimed to analyze the characteristic clinical manifestations of patients with intestinal disease Meckel's diverticulum (MD) complicated by digestive tract hemorrhage. Moreover, we aimed to evaluate the value of double-balloon enteroscopy (DBE) in MD diagnosis and the prognosis after laparoscopic diverticula resection. AIM: To evaluate the value of DBE in the diagnosis and the prognosis after laparoscopic diverticula resection for MD with bleeding. METHODS: The study retrospectively analyzed relevant data from 84 MD patients treated between January 2015 and March 2022 and recorded their clinical manifestations, auxiliary examination, and follow-up after laparoscopic resection of diverticula. RESULTS: (1) Among 84 MD patients complicated with hemorrhage, 77 were male, and 7 were female with an average age of 31.31 ± 10.75 years. The incidence was higher in men than in women of different ages; (2) Among the 84 MD patients, 65 (78.40%) had defecated dark red stools, and 50 (58.80%) had no accompanying symptoms during bleeding, indicating that most MD bleeding appeared a dark red stool without accompanying symptoms; (3) The shock index of 71 patients (85.20%) was < 1, suggesting that the blood loss of most MD patients was less than 20%-30%, and only a few patients had a blood loss of > 30%; (4) The DBE-positive rate was 100% (54/54), 99mTc-pertechnetate-positive scanning rate was 78% (35/45) compared with capsule endoscopy (36%) and small intestine computed tomography (19%). These results suggest that DBE and 99mTc-pertechnetate scans had significant advantages in diagnosing MD and bleeding, especially DBE was a highly precise examination method in MD diagnosis; (5) A total of 54 MD patients with hemorrhage underwent DBE examination before surgery. DBE endoscopy revealed many mucosal manifestations including normal appearance, inflammatory changes, ulcerative changes, diverticulum inversion, and nodular hyperplasia, with ulcerative changes being the most common (53.70%). This suggests that diverticular mucosal ulcer was the main cause of MD and bleeding; and (6) Laparoscopic dissection of diverticulae was performed in 76 patients, The patients who underwent postoperative follow-up did not experience any further bleeding. Additionally, follow-up examination of the 8 cases who had declined surgery revealed that 3 of them experienced a recurrence of digestive tract bleeding. These findings indicate that laparoscopic diverticula resection in MD patients complicated by bleeding had a favorable prognosis. CONCLUSION: Bleeding associated with MD was predominantly observed in male adolescents, particularly at a young age. DBE was a highly precise examination method in MD diagnosis. Laparoscopic diverticula resection effectively prevented MD bleeding and had a good prognosis.

The potential association between metabolic disorders and pulmonary tuberculosis: a Mendelian randomization study.

BACKGROUND: Metabolic disorders (MetDs) have been demonstrated to be closely linked to numerous diseases. However, the precise association between MetDs and pulmonary tuberculosis (PTB) remains poorly understood. METHOD: Summary statistics for exposure and outcomes from genome-wide association studies (GWASs) for exposures and outcomes were obtained from the BioBank Japan Project (BBJ) Gene-exposure dataset. The 14 clinical factors were categorized into three groups: metabolic laboratory markers, blood pressure, and the MetS diagnostic factors. The causal relationship between metabolic factors and PTB were analyzed using two-sample Mendelian Randomization (MR). Additionally, the direct effects on the risk of PTB were investigated through multivariable MR. The primary method employed was the inverse variance-weighted (IVW) model. The sensitivity of this MR analysis was evaluated using MR-Egger regression and the MR-PRESSO global test. RESULTS: According to the two-sample MR, HDL-C, HbA1c, TP, and DM were positively correlated with the incidence of active TB. According to the multivariable MR, HDL-C (IVW: OR 2.798, 95% CI 1.484-5.274, P = 0.001), LDL (IVW: OR 4.027, 95% CI 1.140-14.219, P = 0.03) and TG (IVW: OR 2.548, 95% CI 1.269-5.115, P = 0.009) were positively correlated with the occurrence of PTB. TC (OR 0.131, 95% CI 0.028-0.607, P = 0.009) was negatively correlated with the occurrence of PTB. We selected BMI, DM, HDL-C, SBP, and TG as the diagnostic factors for metabolic syndrome. DM (IVW, OR 1.219, 95% CI 1.040-1.429 P = 0.014) and HDL-C (IVW, OR 1.380, 95% CI 1.035-1.841, P = 0.028) were directly correlated with the occurrence of PTB. CONCLUSIONS: This MR study demonstrated that metabolic disorders, mainly hyperglycemia, and dyslipidemia, are associated with the incidence of active pulmonary tuberculosis.

Synthesis of Spiro Polycyclic N-Heterocycles and Indolecarbazoles via Merging Oxidative Coupling and Cascade Palladium-Catalyzed Intramolecular Oxidative Cyclization.

We report a step-economic strategy for the direct synthesis of spiro polycyclic N-heterocycles and indolecarbazole-fused naphthoquinones by merging oxidative coupling and cascade palladium-catalyzed intramolecular oxidative cyclization. In the protocol, bi-indolylnaphthoquinones were first synthesized by oxidative coupling of indoles and naphthoquinones. Subsequent cascade palladium-catalyzed intramolecular oxidative cyclization of bi-indolylnaphthoquinones gave spiro polycyclic N-heterocycles and indolecarbazoles. The intramolecular oxidative cyclization approach could also be realized by the presence or absence of iron catalysts under standard conditions. This protocol is featured with moderate to excellent yields, a wide substrate scope, and divergent structures of products.

Advancements in the synthesis of carbon dots and their application in biomedicine.

As a sort of fluorescent carbon nanomaterial with a particle size of less than 10 nm, carbon dots (CDs) have their own merits of good dispersibility in water, stable optical properties, strong chemical inertness, stable optical properties, and good biosecurity. These excellent peculiarities facilitated them like sensing, imaging, medicine, catalysis, and optoelectronics, making them a new star in the field of nanotechnology. In particular, the development of CDs in the fields of chemical probes, imaging, cancer therapy, antibacterial and drug delivery has become a hot topic in current research. Although the biomedical applications in CDs have been demonstrated in many research articles, a systematic summary of their role in biomedical applications is scarce. In this review, we introduced the basic information of CDs in detail, including synthesis approaches of CDs as well as their favorable properties including photoluminescence and low cytotoxicity. Subsequently, the application of CDs in the field of biomedicine was emphasized. Finally, the main challenges and research prospects of CDs in this field were proposed, which might provide some detailed information in designing new CDs in this promising biomedical field.

A Porphyrin-Based 3D Metal-Organic Framework Featuring [Cu8Cl6]10+ Cluster Secondary Building Units: Synthesis, Structure Elucidation, Anion Exchange, and Peroxidase-Like Activity.

Herein, we report a rare example of cationic three-dimensional (3D) metal-organic framework (MOF) of [Cu5Cl3(TMPP)]Cl5 ⋅ xSol (denoted as Cu-TMPP; H2TMPP=meso-tetrakis (6-methylpyridin-3-yl) porphyrin; xSol=encapsulated solvates) supported by [Cu8Cl6]10+ cluster secondary building units (SBUs) wherein the eight faces of the Cl--based octahedron are capped by eight Cu2+. Surface-area analysis indicated that Cu-TMPP features a mesoporous structure and its solvate-like Cl- counterions can be exchanged by BF4 -, PF6 -, and NO3 -. The polyvinylpyrrolidone (PVP) coated Cu-TMPP (denoted as Cu-TMPP-PVP) demonstrated good ROS generating ability, producing ⋅OH in the absence of light (peroxidase-like activity) and 1O2 on light irradiation (650 nm; 25 mW cm-2). This work highlights the potential of Cu-TMPP as a functional carrier of anionic guests such as drugs, for the combination therapy of cancer and other diseases.

First Report of Paramyrothecium breviseta Causing Target Spot on Amorphophallus muelleri in Yunnan, China.

Amorphophallus muelleri is an Araceae plant with perennial tuber, widely used in food, pharmaceutical and chemical industry due to its richness in glucomannan. In April 2022, an outbreak of a target spot on A. muelleri plantlets was observed in a nursery in Ruili, Yunnan, China. The leafstalks of the diseased plantlets in the nursery turned brown and decayed (Fig.1 A-B), then gradually some water-soaked spots on the true leaves developed along the veins (Fig.1 A). Subquencely, the spots on the true leaves turned dark green to white-grayish in the center, which formed light to dark brown concentric rings with a target-like appearance surrounded by a yellow halo (Fig.1 C). When the temperature was 20-34℃ and the relatively humidity was 25-80%, dark-green to black sporodochia with white hypha appeared on the lower and upper leaf surfaces. Finally, 5-8% of the plants surveyed on 800 m2 of one-year-old plantlets in the nursery showed the symptoms and some plants with infected leafstalks would be death. Similar symptoms were also observed on about 10% of the transplanted plants surveyed on 12000 m2 (1.2 ha) of two-year-old plantlets in the field. Five diseased leaves from five distinct plantlets in the nursery were collected for pathogen isolation. Leaf pieces(5 x 5 mm) were cut from the edge of necrotic lesions, and surface-sterilized with 2.5% sodium hypochlorite for 1 min, 75% ethanol for 30 s, then rinsed 5 times by sterilized distilled water, finally put the leaf pieces on sterilized filter paper for 3-5 minutes to dry them and transferred onto potato dextrose agar (PDA) in petri dishes at 25℃ for three days. Five pure cultures identical to colony and conidial characteristics were isolated from five individual plants. The representative pure culture (M1) was grayish-white and circular colonies were 7.50 cm in diamter after 15 days at 25℃, with dark green concentric rings of sporodochia, the dorsal view of the colonies were yellowish. Conidia were aseptate, smooth, cylindrical, 5.00-6.25 (5.71) x 1.25-1.67 (1.63) µm (n = 20) rounded at both ends. A spore suspension (1 x 106 spores/ml) was prepared by harvesting spores from 15-day-old cultures grown in the dark at 25℃, then a thirty-ml of spore suspension was sprayed on the healthy leaves of 10 two-year-old plantlets. Thirty-ml of sterile water was sprayed on the healthy leaves of another 10 seedlings and used as the control. All seedlings were placed in a nursery at 20 to 34℃ and a relative humidity of 25 to 80%. Similar symptoms (Fig.1 D-F) to those observed in the nursery and field developed on all the 10 seedlings inoculated with M1 after two days, but not on the control leaves. The pathogenicity tests were repeated for three times. Fungal cultures reisolated from the infected leaves were identical to the original colonies and conidia, completing Koch's postulates. The internal transcribed spacer (ITS, primers ITS1 and ITS4) region of ribosomal DNA (OQ553785), calmodulin (cmdA, primers CAL-228F and CAL2Rd)(OQ559103), RNA polymerase II second largest subunit (rpb2, primers RPB2-5F2 and RPB2-7cR) (OQ559104) and ß-tubulin (tub2, primers Bt2a and Bt2b) (OQ559105) of M1 had 100%, 98.52%, 98.98% and 98.98% identity with the sequences of Paramyrothecium breviseta CBS544.75 (KU846289 for ITS, KU846262 for cmdA, KU846351 for rpb2, and KU846406 for tub2), respectively. In the phylogenic tree based on ITS, cmdA, rpb2 and tub2 gene sequences, the pure culture M1 clustered with P. breviseta CBS544.75, SDBR-CMU387, DRL4 and DRL3, which has been reported as the pathogen of leaf spot of Coffea arabica in China, C. canephora in China and Thailand (Wu et al. 2021; Withee et al. 2022). Molecular and morphological observations showed the pure culture M1 were P. breviseta (Withee et al. 2022), in addition the disease was named as target spot dueing to the typical target symptom on the leaves. To our knowledge, this is the first report of P. breviseta on A. muelleri from Yunnan, China, as well as worldwide. This disease can caused serious economic losses of A. muelleri dueing to that it can result 5-8% death of the plants in the nursery.