Non-cytotoxic nanomolar concentration of arctigenin protects neuronal cells from chemotherapy-induced ferroptosis by regulating SLC7A11-cystine-cysteine axis

Neurotoxicity is a common side effect of certain types of therapeutic drugs, posing a major hurdle for their clinical application. Accumulating evidence suggests that ferroptosis is involved in the neurotoxicity induced by these drugs. Therefore, targeting ferroptosis is considered to be a reasonable approach to prevent such side effect. Arctigenin (ATG) is a major bioactive ingredient of Arctium lappa L., a popular medicinal plant in Asia, and has been reported to have multiple bioactivities including neuroprotection. However, the mechanisms underlying the neuroprotection of ATG has not been well elucidated. The purpose of this study was to investigate whether the neuroprotection of ATG was associated with its ability to protect neuronal cells from ferroptosis. Using neuronal cell ferroptosis model induced by either classic ferroptosis induces or therapeutic drugs, we demonstrated for the first time that ATG in the nanomolar concentration range effectively prevented neuronal cell ferroptosis induced by classic ferroptosis inducer sulfasalazine (SAS) and erastin (Era), or therapeutic drug oxaliplatin (OXA) and 5-fluorouracil (5-FU). Mechanistically, we uncovered that the anti-ferroptotic effect of ATG was attributed to its ability to activate SLC7A11-cystine-cysteine axis. The findings of the present study implicate that ATG holds great potential to be developed as a novel agent for preventing SLC7A11 inhibition-mediated neurotoxicity.

Requirements for human natural killer cells

'Requirements for Human Natural Killer Cells' is the latest set of guidelines on human NK cells in China, jointly drafted and agreed upon by experts from the Standards Committee of Chinese Society for Cell Biology. This standard specifies requirements for the human natural killer (NK) cells, including the technical requirements, test methods, test regulations, instructions for use, labeling requirements, packaging requirements, storage and transportation requirements, and waste disposal requirements of NK cells. This standard is applicable for the quality control of NK cells, derived from human tissues, or differentiated/transdifferentiated from stem cells. It was originally released by the Chinese Society for Cell Biology on 30 August, 2022. We hope that the publication of these guidelines will promote institutional establishment, acceptance, and execution of proper protocols and accelerate the international standardization of human NK cells for applications.

A chimeric adenovirus-vectored vaccine based on Beta spike and Delta RBD confers a broad-spectrum neutralization against Omicron-included SARS-CoV-2 variants

Urgent research into innovative severe acute respiratory coronavirus-2 (SARS-CoV-2) vaccines that may successfully prevent various emerging emerged variants, particularly the Omicron variant and its subvariants, is necessary. Here, we designed a chimeric adenovirus-vectored vaccine named Ad5-Beta/Delta. This vaccine was created by incorporating the receptor-binding domain from the Delta variant, which has the L452R and T478K mutations, into the complete spike protein of the Beta variant. Both intramuscular (IM) and intranasal (IN) vaccination with Ad5-Beta/Deta vaccine induced robust broad-spectrum neutralization against Omicron BA.5-included variants. IN immunization with Ad5-Beta/Delta vaccine exhibited superior mucosal immunity, manifested by higher secretory IgA antibodies and more tissue-resident memory T cells (TRM) in respiratory tract. The combination of IM and IN delivery of the Ad5-Beta/Delta vaccine was capable of synergically eliciting stronger systemic and mucosal immune responses. Furthermore, the Ad5-Beta/Delta vaccination demonstrated more effective boosting implications after two dosages of mRNA or subunit recombinant protein vaccine, indicating its capacity for utilization as a booster shot in the heterologous vaccination. These outcomes quantified Ad5-Beta/Delta vaccine as a favorable vaccine can provide protective immunity versus SARS-CoV-2 pre-Omicron variants of concern and BA.5-included Omicron subvariants.

The research progress on the impact of antibiotics on the male reproductive system

Antibiotics are extensively utilized in the livestock and poultry industry and can accumulate in animals and the environment, leading to potential health risks for humans via food and water consumption. Research on antibiotic toxicity, particularly their impact as endocrine disruptors on the male reproductive system, is still in its nascent stages. This review highlights the toxic effect of antibiotics on the male reproductive system, detailing the common routes of exposure and the detrimental impact and mechanisms of various antibiotic classes. Additionally, it discusses the protective role of food-derived active substances against the reproductive toxicity induced by antibiotics. This review aims to raise awareness about the reproductive toxicity of antibiotics in males and to outline the challenges that must be addressed in future research.

[Neoadjuvant strategy for locally advanced colorectal cancer based organ preservation]

Neoadjuvant therapy for locally advanced colorectal cancer has made great progress in the past 20 years, but there are still limitations such as side effects, organ dysfunction and unsatisfactory control of metastasis. In recent years, with the improvement of surgical techniques and further development of molecular research, how to further improve local control, reduce distant metastasis, and even avoid surgery according to clinical remission to achieve organ preservation, is the current demand and research goal. With the advancement of molecular research, colorectal cancer has different treatment strategies based on microsatellite status. For patients with microsatellite instability locally advanced colorectal cancer, immune checkpoint inhibitor therapy significantly increased the pathologic complete response rate, reduced the incidence of adverse events and improved organ function compared with conventional chemoradiotherapy. For patients with microsatellite stable locally advanced colon cancer, neoadjuvant therapy is still in the exploratory stage. The standard of care is surgery combined with perioperative chemotherapy. For microsatellite stable locally advanced rectal cancer, the complete response rate is improved by enhancing neoadjuvant therapy, which helps to preserve organs. On the other hand, selective radiotherapy preserves organ function and improves quality of life. This article reviews the neoadjuvant treatment strategies for locally advanced colorectal cancer based on organ-sparing strategies.

Nonlinear relationship between viral load and TCT in single/multiple HPV52 infection

PURPOSE

To determine the correlation between HPV (human papillomavirus) 52 viral load, multiple infections and ThinPrep cytology test (TCT), to inform clinical management of HPV52-positive women after cervical cancer screening.

METHODS

A total of 1,882 female patients who had positive quantitative HPV tests at Yuebei People's Hospital from January 2020 to December 2022, of whom 533 tested positive for HPV52. We excluded patients who combined HPV16 and/or HPV 18 positivity and whom HPV52 viral load could not be calculated. The final enrollment was 488 patients, including 400 NILM, 48 ASC-US, 28 LSIL and 12 HSIL. The HPV test is a quantitative multiplexed fluorescent PCR assay that provides both HPV genotyping and viral load.

RESULTS

In our study, there were differences in the median distribution of viral loads among various cytological class categories. The risk of TCT results (LSIL or worse) was increased with the increase of HPV52 viral load, for every LOG unit increase in HPV52 viral load, the risk increased by 26.6%. More importantly, we found a nonlinear relationship between HPV52 viral load and TCT results (LSIL or worse) in both single and multiple infections. When the viral load reaches a threshold, the risk of abnormal cytological results increases significantly.

CONCLUSION

HPV52 viral load is an independent risk factor for TCT results (LSIL or worse). The relationship between HPV52 viral load and TCT results (LSIL or worse) is not linear. Viral load may be used as a triage indicator for HPV52-positive patients, thus improving the post-screening clinical management of HPV52-positive women.

Role of ferroptosis in food-borne mycotoxin-induced toxicities

Contamination by toxic substances is a major global food safety issue, which poses a serious threat to human health. Mycotoxins are major class of food contaminants, mainly including aflatoxins (AFs), zearalenone (ZON), deoxynivalenol (DON), ochratoxin A (OTA), fumonisins (FBs) and patulin (PAT). Ferroptosis is a newly identified iron-dependent form of programmed or regulated cell death, which has been found to be involved in diverse pathological conditions. Recently, a growing body of evidence has shown that ferroptosis is implicated in the toxicities induced by certain types of food-borne mycotoxins, which provides novel mechanistic insights into mycotoxin-induced toxicities and paves the way for developing ferroptosis-based strategy to combat against toxicities of mycotoxins. In this review article, we summarize the key findings on the involvement of ferroptosis in mycotoxin-induced toxicities and propose issues that need to be addressed in future studies for better utilization of ferroptosis-based approach to manage the toxic effects of mycotoxin contamination.

cGAS-STING, an important signaling pathway in diseases and their therapy

Since cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway was discovered in 2013, great progress has been made to elucidate the origin, function, and regulating mechanism of cGAS-STING signaling pathway in the past decade. Meanwhile, the triggering and transduction mechanisms have been continuously illuminated. cGAS-STING plays a key role in human diseases, particularly DNA-triggered inflammatory diseases, making it a potentially effective therapeutic target for inflammation-related diseases. Here, we aim to summarize the ancient origin of the cGAS-STING defense mechanism, as well as the triggers, transduction, and regulating mechanisms of the cGAS-STING. We will also focus on the important roles of cGAS-STING signal under pathological conditions, such as infections, cancers, autoimmune diseases, neurological diseases, and visceral inflammations, and review the progress in drug development targeting cGAS-STING signaling pathway. The main directions and potential obstacles in the regulating mechanism research and therapeutic drug development of the cGAS-STING signaling pathway for inflammatory diseases and cancers will be discussed. These research advancements expand our understanding of cGAS-STING, provide a theoretical basis for further exploration of the roles of cGAS-STING in diseases, and open up new strategies for targeting cGAS-STING as a promising therapeutic intervention in multiple diseases.

Measurements of All-Particle Energy Spectrum and Mean Logarithmic Mass of Cosmic Rays from 0.3 to 30 PeV with LHAASO-KM2A

We present the measurements of all-particle energy spectrum and mean logarithmic mass of cosmic rays in the energy range of 0.3-30 PeV using data collected from LHAASO-KM2A between September 2021 and December 2022, which is based on a nearly composition-independent energy reconstruction method, achieving unprecedented accuracy. Our analysis reveals the position of the knee at 3.67±0.05±0.15  PeV. Below the knee, the spectral index is found to be -2.7413±0.0004±0.0050, while above the knee, it is -3.128±0.005±0.027, with the sharpness of the transition measured with a statistical error of 2%. The mean logarithmic mass of cosmic rays is almost heavier than helium in the whole measured energy range. It decreases from 1.7 at 0.3 PeV to 1.3 at 3 PeV, representing a 24% decline following a power law with an index of -0.1200±0.0003±0.0341. This is equivalent to an increase in abundance of light components. Above the knee, the mean logarithmic mass exhibits a power law trend towards heavier components, which is reversal to the behavior observed in the all-particle energy spectrum. Additionally, the knee position and the change in power-law index are approximately the same. These findings suggest that the knee observed in the all-particle spectrum corresponds to the knee of the light component, rather than the medium-heavy components.

Age-, sex- and proximal-distal-resolved multi-omics identifies regulators of intestinal aging in non-human primates

The incidence of intestinal diseases increases with age, yet the mechanisms governing gut aging and its link to diseases, such as colorectal cancer (CRC), remain elusive. In this study, while considering age, sex and proximal-distal variations, we used a multi-omics approach in non-human primates (Macaca fascicularis) to shed light on the heterogeneity of intestinal aging and identify potential regulators of gut aging. We explored the roles of several regulators, including those from tryptophan metabolism, in intestinal function and lifespan in Caenorhabditis elegans. Suggesting conservation of region specificity, tryptophan metabolism via the kynurenine and serotonin (5-HT) pathways varied between the proximal and distal colon, and, using a mouse colitis model, we observed that distal colitis was more sensitive to 5-HT treatment. Additionally, using proteomics analysis of human CRC samples, we identified links between gut aging and CRC, with high HPX levels predicting poor prognosis in older patients with CRC. Together, this work provides potential targets for preventing gut aging and associated diseases.

18β-glycyrrhetinic acid suppresses Lewis lung cancer growth through protecting immune cells from ferroptosis

PURPOSE

18β-glycyrrhetinic acid (GA), the main metabolite of glycyrrhizic acid extracted from the root of licorice, has been reported to possess anti-cancer and immunomodulatory activity, but the mechanisms are not well understood. Recent studies have shown that ferroptosis of immune cells is involved in tumor-associated immune suppression. The purpose of this study was to investigate whether the enhanced immune response via inhibiting immune cell ferroptosis contributed to the anticancer effect of 18β-GA.

METHODS

Lewis Lung carcinoma mouse model and Murine CD8 + T cell culture model were used to examine the changes of immune response and ferroptosis of immune cells.

RESULTS

We found that 18β-GA was effective against lung cancer accompanied by enhanced activation of tumor-infiltrating CD8+ T cells in Lewis Lung carcinoma mouse model. Furthermore, we demonstrated that the boosted immune response by GA was attributed to its ability to inhibit arachidonic acid (AA)-mediated CD8+ T ferroptosis via suppressing CD36 expression.

CONCLUSION

The findings of the present study unraveled a novel mechanism underlying the anti-cancer and immunomodulatory activity of 18β-GA and support that 18β-GA holds potential to be used as an immune enhancer for lung cancer prevention or treatment.

Glycyrol Alleviates Acute Kidney Injury by Inhibiting Ferroptsis

Acute kidney injury (AKI) is a common clinical problem with high morbidity and mortality. The discovery of ferroptosis has provided novel insights into the mechanisms underlying AKI and paves the way for developing ferroptosis-based approaches to treat AKI. Glycyrol (GC) is a representative coumarin compound isolated from licorice that demonstrates various pharmacological activities. However, its potential for a protective effect against kidney injury remains unknown. We hypothesized that GC might be able to protect against AKI via suppression of ferroptosis. This hypothesis was tested in a cell-culture model of RSL3-induced nephrocyte ferroptosis and a mouse model of folic acid-induced AKI. The results showed that GC exerted a significant protective effect against nephrocyte ferroptosis in vitro and was effective against folic acid-induced AKI in vivo, where it was mechanistically associated with suppressing HO-1-mediated heme degradation. Collectively, the findings of the present study support the hypothesis that GC holds considerable potential to be developed as a novel agent for treating ferroptosis-related AKI.

[The application of full-length urethral preservation without anastomosis in single-port laparoscopic radical prostate cancer]

Objective: To preliminarily examine the feasibility and outcome of single-port laparoscopic radical prostatectomy with full-length urethral preservation (FLUP-SPRP). Method: This study was a prospective case series study. A total of 25 patients with prostate cancer who met the enrollment criteria and agreed to this surgical procedure from March 2022 to December 2022 were collected at the Department of Urology, the Second Affiliated Hospital of Nanjing Medical University. The age of the patients was (67.2±7.6) years (range: 61 to 76 years). This novel procedure was performed by an experienced surgeon who performed single hole radical prostatectomy skillfully. Patient urinary control, tumor control, and related surgical complications after surgery were regularly monitored. Postoperative urinary control was evaluated using the daily amount of urine pad, 0 to 1 piece of urine pad was to restore urinary control, and 0 to 1 piece of pad within 24 hours after catheter removal was immediate urinary control. Result: All prodecures were successfully completed without transit to open surgery. The surgical time was (128.4±22.4) minutes (range: 100 to 145 minutes), the intraoperative blood loss was (68.2±13.7) ml (range: 50 to 120 ml). The urethral injury occurred in 4 cases during surgery and was repaired by sutures. The urinary control recovery rates within 24 hours, 1 week, 4 weeks, and 7 weeks after surgery were 80.0%, 84.0%, 92.0% and 100%, respectively. Postoperative large section pathology revealed 1 case with a positive basal margin of the prostate and negative margins of all prostate glands around the urethra. Postoperative complications included urinary tract infection in 3 cases, urodynia in 2 cases, and acute urinary retention in 1 case. MRI follow-up 3 months after surgery showed normal anatomy of the bladder and urethra. The follow-up values of prostate specific antigen at 3 and 6 months after surgery were less than 0.1 μg/L. Conclusions: The preliminary results of this study indicate that the FLUP-SPRP procedure is safe and feasible. The early results of postoperative urinary control and oncology are as expected.

Mechanisms and therapeutic implications of selective autophagy in nonalcoholic fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease worldwide, whereas there is no approved drug therapy due to its complexity. Studies are emerging to discuss the role of selective autophagy in the pathogenesis of NAFLD, because the specificity among the features of selective autophagy makes it a crucial process in mitigating hepatocyte damage caused by aberrant accumulation of dysfunctional organelles, for which no other pathway can compensate.

AIM OF REVIEW

This review aims to summarize the types, functions, and dynamics of selective autophagy that are of particular importance in the initiation and progression of NAFLD. And on this basis, the review outlines the therapeutic strategies against NAFLD, in particular the medications and potential natural products that can modulate selective autophagy in the pathogenesis of this disease.

KEY SCIENTIFIC CONCEPTS OF REVIEW

The critical roles of lipophagy and mitophagy in the pathogenesis of NAFLD are well established, while reticulophagy and pexophagy are still being identified in this disease due to the insufficient understanding of their molecular details. As gradual blockage of autophagic flux reveals the complexity of NAFLD, studies unraveling the underlying mechanisms have made it possible to successfully treat NAFLD with multiple pharmacological compounds that target associated pathways. Overall, it is convinced that the continued research into selective autophagy occurring in NAFLD will further enhance the understanding of the pathogenesis and uncover novel therapeutic targets.

Delta-tocotrienol disrupts PD-L1 glycosylation and reverses PD-L1-mediated immune suppression

PD-L1-mediated immune escape plays an important role in cancer development and progression. Targeting PD-L1 is consider to be an attractive approach for cancer treatment. PD-L1 is a heavily N-linked glycosylated protein, and the glycosylation of PD-L1 is essential for its ability to interact with its receptor PD-1 to mediate immune suppression. In the present study, we demonstrated for the first time that delta-tocotrienol (δ-T3) not any of the other forms of vitamin E was able to disrupt PD-L1 glycosylation mechanistically associated with the suppression of TCF4-STT3a/STT3b axis. The inhibition of PD-L1 glycosylation by δ-T3 resulted in the decrease of PD-L1 expression and its exosomal secretion, leading to the reduction of PD-L1 and PD-1 interaction, and reversing PD-L1-mediated immune suppression, which in turn contributed to the inhibitory effect on tumor growth. The findings of the present study provide a novel mechanistic interpretation for the superior anticancer activity of δ-T3 among 8 isomers of the vitamin E.

MRI-based radiomics model for preoperative prediction of extramural venous invasion of rectal adenocarcinoma

BACKGROUND

Extramural venous invasion (EMVI) is an important prognostic factor of rectal adenocarcinoma. However, accurate preoperative assessment of EMVI remains difficult.

PURPOSE

To assess EMVI preoperatively through radiomics technology, and use different algorithms combined with clinical factors to establish a variety of models in order to make the most accurate judgments before surgery.

MATERIAL AND METHODS

A total of 212 patients with rectal adenocarcinoma between September 2012 and July 2019 were included and distributed to training and validation datasets. Radiomics features were extracted from pretreatment T2-weighted images. Different prediction models (clinical model, logistic regression [LR], random forest [RF], support vector machine [SVM], clinical-LR model, clinical-RF model, and clinical-SVM model) were constructed on the basis of radiomics features and clinical factors, respectively. The area under the curve (AUC) and accuracy were used to assess the predictive efficacy of different models. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were also calculated.

RESULTS

The clinical-LR model exhibited the best diagnostic efficiency with an AUC of 0.962 (95% confidence interval [CI] = 0.936-0.988) and 0.865 (95% CI = 0.770-0.959), accuracy of 0.899 and 0.828, sensitivity of 0.867 and 0.818, specificity of 0.913 and 0.833, PPV of 0.813 and 0.720, and NPV of 0.940 and 0.897 for the training and validation datasets, respectively.

CONCLUSION

The radiomics-based prediction model is a valuable tool in EMVI detection and can assist decision-making in clinical practice.

Liver protecting effects and molecular mechanisms of icariin and its metabolites

As a detoxification and metabolism organ, the liver plays a vital role in human health. However, an excessive consumption of drugs and toxins, exposure to pathogenic viruses, and unhealthy living habits can lead to liver damage, which may even develop into liver cirrhosis and liver cancer. Epimedium brevicornum Maxim. is a traditional Chinese medicine and dietary supplement in which the flavonoid icariin is a main functional component. Although the protective mechanisms of icariin and its metabolites against liver injury are not yet comprehensively understood, an increasing number of studies have confirmed their liver-protective and anticancer effects. Indeed, icaritin, one of the metabolites of icariin, is currently utilized as an active component of an anti-cancer drug. This paper presents a review of the molecular mechanisms through which icariin and its metabolites actively protect against the occurrence and development of liver injury, and, thus, provides a comprehensive reference for further research and their application in liver protection.

Regulation of M1/M2 Polarization in LPS-Stimulated Macrophages by 1,25(OH)2D3

Objective

This study aims to investigate the impact of 1,25(OH)2D3 on the polarization of LPS-stimulated macrophages and the underlying regulatory mechanisms.

Methods

Primary macrophages were isolated and identified using immunofluorescence assays to detect macrophage biomarker expression levels. RT-PCR was employed to measure the expression of Arginase 1 (Arg-1), Interleukin-10 (IL-10), Inducible isoform of nitric oxide synthase (iNOS), and Tumor necrosis factor-α (TNF-α) in macrophages treated with various strategies. Western blotting assessed the protein expression levels of AKT1, p-AKT1, NF-κB p65, p-NF-κB p65, STAT3, and p-STAT3 in LPS-stimulated macrophages exposed to different concentrations of 1,25(OH)2D3.

Results

As the LPS concentration increased from 0 to 0.5 mg/L, Arg-1, IL-10, iNOS, and TNF-α expression levels significantly increased. However, at LPS concentrations ranging from 1 mg/L to 10 mg/L, the expression of Arg-1, IL-10, iNOS, and TNF-α displayed a trend from increase to decline. The highest M2 polarization (Arg-1 and IL-10) was observed in macrophages stimulated with 0.5 mg/L LPS among the lower concentrations, while the highest M1 polarization (iNOS and TNF-α) was observed in macrophages stimulated with 5 mg/L LPS among the higher concentrations. Subsequent experiments utilized 0.5 mg/L and 5 mg/L LPS as incubation concentrations. Under LPS stimulation, iNOS was significantly upregulated, surpassing the expression level of IL-10, a marker of M2 macrophages. The introduction of 1,25(OH)2D3 facilitated M2 polarization, with 50 nM as the incubation concentration of 1,25(OH)2D3. Furthermore, 1,25(OH)2D3 reversed the elevated expression of p-AKT1, p-NF-κB p65, and p-STAT3 in macrophages stimulated with 5 mg/L LPS.

Conclusions

1,25(OH)2D3 effectively regulates the M1/M2 polarization in LPS-stimulated macrophages.

Combination of Selenite and Butyrate Enhances Efficacy Against Colon Cancer by Targeting ASCT2-Mediated Amino Acid Metabolism

Drug combination is considered to be an effective approach to improve the efficacy of cancer therapy and chemoprevention. Selenite, a representative of inorganic form of selenium, and butyrate, a major short-chain fatty acid, are two well-documented colon cancer dietary chemopreventive agents with distinct molecular mechanisms. We hypothesized that combination of selenite and butyrate might produce improved outcome against colon cancer. This hypothesis was tested using both HCT116 human colon cancer cells and its xenograft mouse model in the present study. The in vitro study showed a synergistically inhibitory effect on HCT116 colon cancer cells but not on NCM460 normal human colon mucosal epithelial cells. Consistent with the in vitro study, results of the xenograft mouse model further demonstrated that combination of selenite and butyrate led to improved efficacy in comparison with each agent alone. Mechanistically, the induction of alanine-serine-cysteine transporter 2 (ASCT2) by selenite repressed its inhibitory effect on colon cancer cells, which was reversed by its co-treatment with butyrate. The findings of the present study denote the likely potential for developing selenite/butyrate combination remedy to combat against colon cancer.

Measurement of Ultra-High-Energy Diffuse Gamma-Ray Emission of the Galactic Plane from 10 TeV to 1 PeV with LHAASO-KM2A

The diffuse Galactic γ-ray emission, mainly produced via interactions between cosmic rays and the interstellar medium and/or radiation field, is a very important probe of the distribution, propagation, and interaction of cosmic rays in the Milky Way. In this Letter, we report the measurements of diffuse γ rays from the Galactic plane between 10 TeV and 1 PeV energies, with the square kilometer array of the Large High Altitude Air Shower Observatory (LHAASO). Diffuse emissions from the inner (15°10  TeV). The energy spectrum in the inner Galaxy regions can be described by a power-law function with an index of -2.99±0.04, which is different from the curved spectrum as expected from hadronic interactions between locally measured cosmic rays and the line-of-sight integrated gas content. Furthermore, the measured flux is higher by a factor of ∼3 than the prediction. A similar spectrum with an index of -2.99±0.07 is found in the outer Galaxy region, and the absolute flux for 10≲E≲60  TeV is again higher than the prediction for hadronic cosmic ray interactions. The latitude distributions of the diffuse emission are consistent with the gas distribution, while the longitude distributions show clear deviation from the gas distribution. The LHAASO measurements imply that either additional emission sources exist or cosmic ray intensities have spatial variations.

TRIM55 promotes noncanonical NF-κB signaling and B cell-mediated immune responses by coordinating p100 ubiquitination and processing

The ubiquitination-dependent processing of NF-κB2 (also known as p100) is a critical step in the activation of the noncanonical NF-κB pathway. We investigated the molecular mechanisms regulating this process and showed that TRIM55 was the E3 ubiquitin ligase that mediated the ubiquitination of p100 and coordinated its processing. TRIM55 deficiency impaired noncanonical NF-κB activation and B cell function. Mice with a B cell-specific Trim55 deficiency exhibited reduced germinal center formation and antibody production. These mice showed less severe symptoms than those of control mice upon the induction of a systemic lupus-like disease, suggesting B cell-intrinsic functions of TRIM55 in humoral immune responses and autoimmunity. Mechanistically, the ubiquitination of p100 mediated by TRIM55 was crucial for p100 processing by VCP, an ATPase that mediates ubiquitin-dependent protein degradation by the proteasome. Furthermore, we found that TRIM55 facilitated the interaction between TRIM21 and VCP as well as TRIM21-mediated K63-ubiquitination of VCP, both of which were indispensable for the formation of the VCP-UFD1-NPL4 complex and p100 processing. Together, our results reveal a mechanism by which TRIM55 fine-tunes p100 processing and regulates B cell-dependent immune responses in vivo, highlighting TRIM55 as a potential therapeutic target for lupus-like disease.

Managing ferroptosis-related diseases with indirect dietary modulators of ferroptosis

Ferroptosis is an iron-dependent form of programmed cell death driven by excessive oxidation of polyunsaturated phospholipids on cellular membranes. Accumulating evidence suggests that ferroptosis has been implicated in the pathological process of various diseases, such as cardiovascular diseases, neurological diseases, liver diseases, kidney injury, lung injury, diabetes, and cancer. Targeting ferroptosis is therefore considered to be a reasonable strategy to fight against ferroptosis-associated diseases. Many dietary bioactive agents have been identified to be able to either suppress or promote ferroptosis, indicating that ferroptosis-based intervention by dietary approach may be an effective strategy for preventing and treating diseases associated with ferroptosis dysregulation. In this review, we summarize the present understanding of the functional role of ferroptosis in the pathogenesis of aforementioned diseases with an emphasis on the evidence of managing ferroptosis-related diseases with indirect dietary modulators of ferroptosis and propose issues that need to be addressed to promote practical application of dietary approach targeting ferroptosis.

Biased allosteric activation of ketone body receptor HCAR2 suppresses inflammation

Hydroxycarboxylic acid receptor 2 (HCAR2), modulated by endogenous ketone body β-hydroxybutyrate and exogenous niacin, is a promising therapeutic target for inflammation-related diseases. HCAR2 mediates distinct pathophysiological events by activating Gi/o protein or β-arrestin effectors. Here, we characterize compound 9n as a Gi-biased allosteric modulator (BAM) of HCAR2 and exhibit anti-inflammatory efficacy in RAW264.7 macrophages via a specific HCAR2-Gi pathway. Furthermore, four structures of HCAR2-Gi complex bound to orthosteric agonists (niacin or monomethyl fumarate), compound 9n, and niacin together with compound 9n simultaneously reveal a common orthosteric site and a unique allosteric site. Combined with functional studies, we decipher the action framework of biased allosteric modulation of compound 9n on the orthosteric site. Moreover, co-administration of compound 9n with orthosteric agonists could enhance anti-inflammatory effects in the mouse model of colitis. Together, our study provides insight to understand the molecular pharmacology of the BAM and facilitates exploring the therapeutic potential of the BAM with orthosteric drugs.

A Comprehensive Prediction Model Based on MRI Radiomics and Clinical Factors to Predict Tumor Response After Neoadjuvant Chemoradiotherapy in Rectal Cancer

RATIONALE AND OBJECTIVES

To establish a prediction model for the efficacy of neoadjuvant chemoradiotherapy (nCRT) in patients with locally advanced rectal cancer (LARC), using pretreatment magnetic resonance imaging (MRI) multisequence image features and clinical parameters.

MATERIALS AND METHODS

Patients with clinicopathologically confirmed LARC were included (training and validation datasets, n = 100 and 27, respectively). Clinical data of patients were collected retrospectively. We analyzed MRI multisequence imaging features. The tumor regression grading (TRG) system proposed by Mandard et al was adopted. Grade 1-2 of TRG was a good response group, and grade 3-5 of TRG was a poor response group. In this study, a clinical model, a single sequence imaging model, and a comprehensive model combined with clinical imaging were constructed, respectively. The area under the subject operating characteristic curve (AUC) was used to evaluate the predictive efficacy of clinical, imaging, and comprehensive models. The decision curve analysis method evaluated the clinical benefit of several models, and the nomogram of efficacy prediction was constructed.

RESULTS

The AUC value of the comprehensive prediction model is 0.99 in the training data set and 0.94 in the test data set, which is significantly higher than other models. Radiomic Nomo charts were developed using Rad scores obtained from the integrated image omics model, circumferential resection margin(CRM), DoTD, and carcinoembryonic antigen(CEA). Nomo charts showed good resolution. The calibrating and discriminating ability of the synthetic prediction model is better than that of the single clinical model and the single sequence clinical image omics fusion model.

CONCLUSION

Nomograph, based on pretreatment MRI characteristics and clinical risk factors, has the potential to be used as a noninvasive tool to predict outcomes in patients with LARC after nCRT.

Methylseleninic acid overcomes gefitinib resistance through asparagine-MET-TOPK signaling axis in non-small cell lung cancer cells

Acquired resistance compromises the efficacy of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI)-based therapy for non-small cell lung cancer (NSCLC), and activation of hepatocyte growth factor receptor (MET) is one of the pivotal strategies for cancer cells to acquire refractory phenotype. However, the mechanisms involved in regulating MET activity remain to be further elucidated. Using gefitinib-resistant HCC827GR cell line as a model, we unraveled that the dysregulated amino acid metabolisms reflected by elevated expression of cysteine-preferring transporter 2 (ASCT2), cystine/glutamate antiporter solute carrier family 7 member 11 (SLC7A11) and asparagine synthetase (ASNS) might contribute to survival advantage of HCC827GR cells, and rendered the cells more sensitive to asparagine (ASN) deprivation compared to parental HCC827 cells. We further identified that the increased ASNS expression is a contributing factor for the activation of MET in HCC827GR cells. More importantly, we found that methylseleninic acid (MSeA), a precursor of methylselenol, effectively suppressed tumor growth in HCC827GR xenograft model, which is associated with decrease of intracellular ASN content along with inactivation of MET- T-lymphokine-activated killer cell-originated protein kinase (TOPK) signaling axis. Finally, we demonstrated that combination of MSeA and gefitinib induced a synergistic growth inhibition in HCC827GR cells. The findings of our work reveal that ASN-MET-TOPK signaling axis as a novel mechanism contributed to gefitinib-resistance and combined utilization of gefitinib and MSeA holds potential to improve the efficacy for gefitinib-resistant NSCLC.

A tera-electron volt afterglow from a narrow jet in an extremely bright gamma-ray burst

Some gamma-ray bursts (GRBs) have a tera-electron volt (TeV) afterglow, but the early onset of this has not been observed. We report observations with the Large High Altitude Air Shower Observatory of the bright GRB 221009A, which serendipitously occurred within the instrument field of view. More than 64,000 photons >0.2 TeV were detected within the first 3000 seconds. The TeV flux began several minutes after the GRB trigger, then rose to a peak about 10 seconds later. This was followed by a decay phase, which became more rapid ~650 seconds after the peak. We interpret the emission using a model of a relativistic jet with half-opening angle ~0.8°. This is consistent with the core of a structured jet and could explain the high isotropic energy of this GRB.

Metabolic Degradation and Bioactive Derivative Synthesis of Phenazine-1-Carboxylic Acid by Genetically Engineered Pseudomonas chlororaphis HT66

Phenazine-1-carboxylic acid (PCA) secreted by Pseudomonas chlororaphis has been commercialized and widely employed as an antifungal pesticide. However, it displays potential hazards to nontarget microorganisms and the environment. Although the PCA degradation characteristics have received extensive attention, the biodegradation efficiency is still insufficient to address the environmental risks. In this study, an engineered Pseudomonas capable of degrading PCA was constructed by introducing heterologous PCA 1,2-dioxygenase (PcaA1A2A3A4). By integrating the PCA degradation module in the chemical mutagenesis mutant P3, 7.94 g/L PCA can be degraded in 60 h, which exhibited the highest PCA degradation efficiency to date and was 35.4-fold higher than that of the PCA natural degraders. Additionally, PCA was converted to 1-methoxyphenazine through structure modification by introducing the functional enzymes PhzS_Pa and PhzM_La, which has good antifungal activity and environmental compatibility. This work demonstrates new possibilities for developing PCA-derived biopesticides and enables targeted control of the impact of PCA in diverse environments.

HUNK inhibits epithelial-mesenchymal transition of CRC via direct phosphorylation of GEF-H1 and activating RhoA/LIMK-1/CFL-1

Epithelial-mesenchymal transition (EMT) is associated with the invasive and metastatic phenotypes in colorectal cancer (CRC). However, the mechanisms underlying EMT in CRC are not completely understood. In this study, we find that HUNK inhibits EMT and metastasis of CRC cells via its substrate GEF-H1 in a kinase-dependent manner. Mechanistically, HUNK directly phosphorylates GEF-H1 at serine 645 (S645) site, which activates RhoA and consequently leads to a cascade of phosphorylation of LIMK-1/CFL-1, thereby stabilizing F-actin and inhibiting EMT. Clinically, the levels of both HUNK expression and phosphorylation S645 of GEH-H1 are not only downregulated in CRC tissues with metastasis compared with that without metastasis, but also positively correlated among these tissues. Our findings highlight the importance of HUNK kinase direct phosphorylation of GEF-H1 in regulation of EMT and metastasis of CRC.

Xanthohumol inhibits non-small cell lung cancer via directly targeting T-lymphokine-activated killer cell-originated protein kinase

Xanthohumol is a principal prenylated chalcone isolated from hops. Previous studies have shown that xanthohumol was effective against various types of cancer, but the mechanisms, especially the direct targets for xanthohumol to exert an anticancer effect, remain elusive. Overexpression of T-lymphokine-activated killer cell-originated protein kinase (TOPK) promotes tumorigenesis, invasion and metastasis, implying the likely potential for targeting TOPK in cancer prevention and treatment. In the present study, we found that xanthohumol significantly inhibited the cell proliferation, migration and invasion of non-small cell lung cancer (NSCLC) in vitro and suppressed tumor growth in vivo, which is well correlated with inactivating TOPK, evidenced by reduced phosphorylation of TOPK and its downstream signaling histone H3 and Akt, and decreased its kinase activity. Moreover, molecular docking and biomolecular interaction analysis showed that xanthohumol was able to directly bind to the TOPK protein, suggesting that TOPK inactivation by xanthohumol is attributed to its ability to directly interact with TOPK. The findings of the present study identified TOPK as a direct target for xanthohumol to exert its anticancer activity, revealing novel insight into the mechanisms underlying the anticancer activity of xanthohumol.

Autophagy-Based Intervention Strategy in the Management of Hepatotoxicity

Significance: Ample evidence has demonstrated an important role for autophagy as either a protective mechanism or a cause for hepatotoxicity, denoting the likely potentials for targeting autophagy in the prevention or treatment of hepatotoxicity. Recent Advances: The functional role of autophagy in the pathogenesis of hepatotoxicity has been gradually recognized. Mechanistically, the autophagy-mediated protective or promoting effect on hepatotoxicity is attributed to its functions in regulation of oxidative stress, endoplasmic reticulum (ER) stress, lipid metabolism, iron homeostasis, inflammatory response, and programmed cell death. Targeting autophagy as a novel strategy for fighting against hepatotoxicity has demonstrated encouraging efficacy in a number of models. Critical Issues: Clarifying the precise functional role of autophagy in different types of hepatotoxicity is essential for developing a type-specific autophagy-based intervention. Identification of molecular targets and novel agents for effectively and accurately manipulating autophagy is needed for better utilization of an autophagy-based approach to exert beneficial effects on hepatotoxicity. Future Directions: Well-designed clinical trials are needed to validate the efficacy of an autophagy-targeting intervention strategy for hepatotoxicity. Further studies should be also focused on developing novel autophagy-targeting agents that can accurately regulate autophagy based on the characteristics of each type of hepatotoxicity.

Efficacy and safety of anlotinib with PD-1 inhibitors in the treatment of advanced hepatocellular carcinoma: A real-world study

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Background: The IMbrave 150 study opened the door of immuno-oncology (IO) combined with targeted therapy in patients (pts) with hepatocellular carcinoma (HCC). At present, some other combination of IO and tyrosine kinase inhibitors (TKIs) had been proved as efficient regimens in China and there are many ongoing studies on this approach with preliminarily considerable efficacy. Furthermore, the efficacy of this combination still needs to be explored in real-world patients. The aim of this study is to explore the efficacy and safety of anlotinib plus PD-1 inhibitors in the treatment of HCC in real-world. Methods: This is a multi-center, prospective real-world study in pts (N=200) diagnosed as advanced HCC, who evaluated by physician would get benefits from anlotinib alone or in combination with PD-1 inhibitors. The enrolled patients received treatment according to physicians. Clinical efficacy was summarized, and adverse events were documented. Tumor response was assessed by investigators according to RECIST version 1.1. The primary endpoint was overall survival (OS), and the secondary endpoints were progression-free survival (PFS), objective response rate (ORR), disease control rate (DCR) and safety. Results: As of data cutoff date of Aug, 2022, a total of 119 patients were enrolled with a median age of 55 years (range 29-83). Among them 78% ECOG PS 0-1, 21% ECOG PS 2 and 1% ECOG PS 4. 75 pts received anlotinib plus PD-1 inhibitors as first-line treatment, 17 pts as second-line treatment and 7 pts as third-line and above. 76 patients were eligible for response evaluation. The ORR as best response was 11.8% (95%CI: 5.6%, 21.3%). The DCR was 73.7% (95%CI: 62.3%, 83.1%). The preliminarily results indicated that the median OS was 12.5 months (95%CI: 9.7, 15.4), the median PFS was 8.1 months (95%CI: 5.9, 10.3). Any grade treatment-related adverse events (TRAEs) observed in 50% of pts. The most common TRAEs were hypoalbuminemia (18.6%), hypertension (11.4%), decreased white blood cell count (11.4%) and decreased platelet count (10%). Conclusions: Present study indicated that the combination of anlotinib and PD-1 inhibitors exhibited potential efficacy and manageable adverse events in the treatment of advanced HCC in the real world. The conclusion should be validated in more patients included subsequently. Clinical trial information: NCT04954521 .

Constraints on Heavy Decaying Dark Matter from 570 Days of LHAASO Observations

The kilometer square array (KM2A) of the large high altitude air shower observatory (LHAASO) aims at surveying the northern γ-ray sky at energies above 10 TeV with unprecedented sensitivity. γ-ray observations have long been one of the most powerful tools for dark matter searches, as, e.g., high-energy γ rays could be produced by the decays of heavy dark matter particles. In this Letter, we present the first dark matter analysis with LHAASO-KM2A, using the first 340 days of data from 1/2-KM2A and 230 days of data from 3/4-KM2A. Several regions of interest are used to search for a signal and account for the residual cosmic-ray background after γ/hadron separation. We find no excess of dark matter signals, and thus place some of the strongest γ-ray constraints on the lifetime of heavy dark matter particles with mass between 10^{5} and 10^{9}  GeV. Our results with LHAASO are robust, and have important implications for dark matter interpretations of the diffuse astrophysical high-energy neutrino emission.

Dental niche cells directly contribute to tooth reconstitution and morphogenesis

Mammalian teeth develop from the inductive epithelial-mesenchymal interaction, an important mechanism shared by many organs. The cellular basis for such interaction remains elusive. Here, we generate a dual-fluorescence model to track and analyze dental cells from embryonic to postnatal stages, in which Pitx2⁺ epithelium and Msx1⁺ mesenchyme are sufficient for tooth reconstitution. Single-cell RNA sequencing and spatial mapping further revealed critical cellular dynamics during molar development, where tooth germs are organized by Msx1⁺Sdc1⁺ dental papilla and surrounding dental niche. Surprisingly, niche cells are more efficient in tooth reconstitution and can directly regenerate papilla cells through interaction with dental epithelium. Finally, from the dental niche, we identify a group of previously unappreciated migratory Msx1⁺ Sox9⁺ cells as the potential cell origin for dental papilla. Our results indicate that the dental niche cells directly contribute to tooth organogenesis and provide critical insights into the essential cell composition for tooth engineering.

Pan-cancer single-cell analysis reveals the heterogeneity and plasticity of cancer-associated fibroblasts in the tumor microenvironment

Cancer-associated fibroblasts (CAFs) are the predominant components of the tumor microenvironment (TME) and influence cancer hallmarks, but without systematic investigation on their ubiquitous characteristics across different cancer types. Here, we perform pan-cancer analysis on 226 samples across 10 solid cancer types to profile the TME at single-cell resolution, illustrating the commonalities/plasticity of heterogenous CAFs. Activation trajectory of the major CAF types is divided into three states, exhibiting distinct interactions with other cell components, and relating to prognosis of immunotherapy. Moreover, minor CAF components represent the alternative origin from other TME components (e.g., endothelia and macrophages). Particularly, the ubiquitous presentation of endothelial-to-mesenchymal transition CAF, which may interact with proximal SPP1⁺ tumor-associated macrophages, is implicated in endothelial-to-mesenchymal transition and survival stratifications. Our study comprehensively profiles the shared characteristics and dynamics of CAFs, and highlight their heterogeneity and plasticity across different cancer types. Browser of integrated pan-cancer single-cell information is available at https://gist-fgl.github.io/sc-caf-atlas/ .

Ciprofloxacin and enrofloxacin can cause reproductive toxicity via endocrine signaling pathways

Ciprofloxacin (CIP) and enrofloxacin (ENR) are veterinary antibiotics commonly utilized to treat and prevent animal diseases. Environmental and dietary antibiotic residues can directly and indirectly affect the reproductive development of animals and humans. This article investigated the reproductive toxicity of CIP in male zebrafish, showing that it could decrease the spermatogonial weight and damage the spermatogonial tissue. The sex hormone assays showed that CIP decreased fshb and lhb gene expression and plasma testosterone (T). In addition, transcriptome analysis indicated that the effect of CIP on zebrafish might be related to the endocrine signaling pathways. ENR, which was selected for further study, inhibited mouse Leydig (TM3) and Sertoli (TM4) cell proliferation and caused cell cycle arrest. The sperm concentration, serum luteotropic hormone (LH) and follicle-stimulating hormone (FSH), and T levels decreased in adolescent mice after ENR treatment for 30d in vivo. Hematoxylin and eosin (H&E) staining showed that ENR exposure potentially induced testicular injury, while the real-time quantitative PCR (qPCR) results indicated that ENR inhibited the mRNA expression of key genes in the Leydig cells (cyp11a1, 3β-HSD, and 17β-HSD), Sertoli cells (Inhbβ and Gdnf) and spermatogenic cells (Plzf, Stra8 and Dmc1). In conclusion, these findings indicated that ENR exposure might influence the development of the testes of pubescent mice.

Inhibition of PD-L1-mediated tumor-promoting signaling is involved in the anti-cancer activity of β-tocotrienol

Programmed death-ligand 1 (PD-L1), a critical immune checkpoint ligand, is commonly overexpressed on the surface of many tumor types including lung and prostate cancer. PD-L1 can exert cancer-promoting activity through either suppressing T cell-mediated immune response or activating tumor-intrinsic signaling. Here, we demonstrated that β-tocotrienol (β-T3), an isomer of vitamin E, effectively inhibited PD-L1 expression both in vitro and in vivo, which was mechanistically associated inactivating JAK2/STAT3 pathway. Down-regulating PD-L1 expression by β-T3 led to enhanced immune response and inactivation of PD-L1-induced tumor-intrinsic signaling, which in turn contributed to its anticancer activity. This study uncovered a novel mechanism involved in the anticancer effect of β-T3.

Combined toxicity of food-borne mycotoxins and heavy metals or pesticides

Food can be contaminated by multiple classes of toxic substances, mainly including mycotoxins, heavy metals and pesticides, which leads to a possibility of simultaneous exposure to two or more food contaminants for humans. Thus, it is necessary to examine whether the combined exposure could result in enhanced toxicity. Initially, the studies on the combined toxicity of food contaminants mainly focus on the mixtures of same classes of food contaminants due to their co-occurrence feature in foodstuffs, such as mixtures of mycotoxins or mixtures of heavy metals. Given the possibility that consumers are likely exposed to mixtures of different classes of food contaminants, recently, studies on the combined toxicity of different classes of food contaminants have been receiving increasing attentions. In this review article, we summarize the findings of combined toxicity studies related to co-exposure to food-borne mycotoxins and other classes of food contaminants mainly heavy metals or pesticides, and propose issues that need to be addressed in future studies for more accurately performing risk assessment of co-exposure to mycotoxins and other classes of food contaminants.

The prevalence of human papillomavirus among women in northern Guangdong Province of China

Globally, cervical cancer, whose etiologic factor is Human papillomavirus (HPV), is the third most common cancer among women. In cervical cancer screening, HPV testing is important. However, the prevalence of HPV in northern Guangdong Province has not been conclusively determined. A total of 100,994 women attending Yuebei People's Hospital Affiliated to Shantou University Medical College between 2012 and 2020 were recruited. HPV was tested by a polymerase chain reaction (PCR)-based hybridization gene chip assay. The prevalence of HPV among these women was established to be19.04%. Peak prevalence was observed in women aged 40-49 (7.29%). Besides, the prevalence of single-type HPV infection (14.46%) was significantly high, compared to multiple-type infection (4.58%) (p < 0.01), while the prevalence of high-risk HPV infection (19.97%) was significantly higher than that of low-risk genotypes (5.48%) (p < 0.01). The most prevalent high-risk genotypes were HPV52 (4.16%), HPV16 (2.98%), HPV58 (2.15%), HPV53 (1.58%) and HPV68 (1.34%). HPV co-infection with up to 10 genotypes was reported for the first time. Our findings suggested a high burden of HPV infections among women in northern Guangdong. Establishing the prevalence and genotype distribution characteristics of HPV infections in the region can contribute to cervical cancer prevention through HPV vaccination.

Ferroptosis promotes T-cell activation-induced neurodegeneration in multiple sclerosis

While many drugs are effective at reducing the relapse frequency of multiple sclerosis (MS), there is an unmet need for treatments that slow neurodegeneration resulting from secondary disease progression. The mechanism of neurodegeneration in MS has not yet been established. Here, we discovered a potential pathogenetic role of ferroptosis, an iron-dependent regulated cell death mechanism, in MS. We found that critical ferroptosis proteins (acyl-CoA synthetase long-chain family member 4, ACSL4) were altered in an existing genomic database of MS patients, and biochemical features of ferroptosis, including lipid reactive oxygen species (ROS) accumulation and mitochondrial shrinkage, were observed in the experimental autoimmune encephalitis (EAE) mouse model. Targeting ferroptosis with ferroptosis inhibitors or reducing ACSL4 expression improved the behavioral phenotypes of EAE mice, reduced neuroinflammation, and prevented neuronal death. We found that ferroptosis was an early event in EAE, which may promote T-cell activation through T-cell receptor (TCR) signaling in vitro and in vivo. These data indicate that ferroptosis may be a potential target for treating MS.

Production of Antibacterial Questiomycin A in Metabolically Engineered Pseudomonas chlororaphis HT66

Pseudomonas chlororaphis has been demonstrated as a valuable source of antimicrobial metabolites for plant disease biocontrol and biopesticide development. Although phenazine-1-carboxylic acid (PCA) secreted by P. chlororaphis has been commercialized as an antifungal biopesticide, it shows poor antibacterial activity. Questiomycin A, with versatile antibacterial activities, is mainly discovered in some well-known phenazine-producing strains but not in Pseudomonas. Its low titer hinders practical applications. In this work, a metabolite was first identified as Questiomycin A in P. chlororaphis-derived strain HT66ΔphzBΔNat. Subsequently, Questiomycin A has been elucidated to share the same biosynthesis process with PCA by gene deletion and in vitro assays. Through rational metabolic engineering, heterologous phenoxazinone synthase introduction, and medium optimization, the titer reached 589.78 mg/L in P. chlororaphis, the highest production reported to date. This work contributes to a better understanding of Questiomycin A biosynthesis and demonstrates a promising approach to developing a new antibacterial biopesticide in Pseudomonas.

RPL38 knockdown inhibits the inflammation and apoptosis in chondrocytes through regulating METTL3-mediated SOCS2 m6A modification in osteoarthritis

BACKGROUND

Ribosomal protein L38 (RPL38) was found upregulated in osteoarthritic peripheral blood mononuclear cells, however, its role in progression of osteoarthritis has not been characterized.

METHODS

The protein levels of RPL38 and SOCS2 in cartilage tissues from OA patients and controls were detected with Western blotting. IL-1β was used to stimulate primary chondrocytes to establish an OA cell model, and RPL38 siRNA (si-RPL38) was transfected into chondrocytes to investigate the effect of RPL38 knockdown on cell viability, apoptosis, inflammatory factor secretion and extracellular matrix degradation. Then, the mechanism that RPL38 regulate the SOCS2 expression and SOCS2-induced chondrocyte dysfunction was explored. The methyltransferase-like 3 (METTL3)-mediated m6A modification of SOCS2 mRNA was confirmed, and the interaction of RPL38 and METTL3 was verified. Moreover, the effects of SOCS2 overexpression on IL-1β-induced chondrocyte dysfunction and SOCS2 knockdown on the restoration of chondrocyte function by siRPL38 were investigated. Finally, RPL38 was knocked down in vivo and its role in OA progression was validated.

RESULTS

RPL38 was upregulated and SOCS2 was downregulated in OA cartilages. RPL38 knockdown or SOCS2 overexpression either attenuated IL-1β-induced chondrocyte apoptosis, inflammatory cytokine secretion, and ECM degradation. RPL38 directly interacted with METTL3 and it inhibited SOCS2 expression through METTL3-mediated m6A modification. SOCS2 knockdown activated the JAK2/STAT3 proinflammatory pathway and reversed the effects of RPL38 knockdown on IL-1β-induced chondrocyte apoptosis, inflammation and ECM degradation. RPL38 knockdown alleviated cartilage tissue damage and ECM degradation in OA mice.

CONCLUSION

RPL38 knockdown inhibited osteoarthritic chondrocyte dysfunction and alleviated OA progression through promoting METTL3-m6A-mediated SOCS2 expression.

Glycyrrhetinic acid restricts mitochondrial energy metabolism by targeting SHMT2

Glycyrrhetinic acid (GA) is a natural product of licorice with mitochondria targeting properties and shows broad anticancer activities, but its targets and underlying mechanisms remain elusive. Here, we identified the mitochondrial enzyme serine hydroxymethyltransferase 2 (SHMT2) as a target of GA by using chemical proteomics. Binding to and inhibiting the activity of SHMT2 by GA were validated in vitro and in vivo. Knockout of SHMT2 or inhibiting SHMT2 with GA restricts mitochondrial energy supplies by downregulating mitochondrial oxidative phosphorylation (OXPHOS) and fatty acid β-oxidation, and consequently suppresses cancer cell proliferation and tumor growth. Crystal structures of GA derivatives indicate that GA occupies SHMT2 folate-binding pocket and regulates SHMT2 activity. Modifications at GA carboxylic group with diamines significantly improved its anticancer potency, demonstrating GA as a decent structural template for SHMT2 inhibitor development.

Development of Artificial Synthetic Pathway of Endophenazines in Pseudomonas chlororaphis P3

Simple Summary

Terpenoid phenazines generally produced in Streptomyces exhibit potential antitumor and antibacterial activities. In this study, we designed and constructed an artificial biosynthetic pathway for the synthesis of terpenoid phenazines in Pseudomonas chlororaphis P3. We successfully synthesized endophenazine A and endophenazine A1 for the first time in Pseudomonas by introducing the prenyltransferase PpzP. Moreover, we revealed the biosynthetic pathway of endophenazine A1 in P. chlororaphis P3. This study enriches the diversity of phenazines in P. chlororaphis P3 and provides a reference for the heterologous synthesis of terpenoid phenazines.

Abstract

Endophenazine A is a terpenoid phenazine with phenazine-1-carboxylic acid (PCA), and dimethylallyl diphosphate (DMAPP) derived from the 2-methyl-D-erythritol-4-phosphate (MEP) pathway as the precursor, which shows good antimicrobial activity against several Gram-positive bacteria and fungi. However, the highest yield of endophenazine A was about 20 mg/L in Streptomyces, limiting its large-scale industrial development. Pseudomonas chlororaphis P3, possessing an efficient PCA synthesis and MEP pathways, is a suitable chassis to synthesize endophenazine A. Herein, we designed an artificial biosynthetic pathway for the synthesis of endophenazine A in P. chlororaphis P3. Primarily, the prenyltransferase PpzP from Streptomyces anulatus 9663 was introduced into P. chlororaphis P3 and successfully synthesized endophenazine A. Another phenazine compound, endophenazine A1, was discovered and identified as a leakage of the intermediate 4-hydroxy-3-methyl-2-butene pyrophosphate (HMBPP). Finally, the yield of endophenazine A reached 279.43 mg/L, and the yield of endophenazine A1 reached 189.2 mg/L by metabolic engineering and medium optimization. In conclusion, we successfully synthesized endophenazine A and endophenazine A1 in P. chlororaphis P3 for the first time and achieved the highest titer, which provides a reference for the heterologous synthesis of terpenoid phenazines.