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The intracellular bacterial pathogen Legionella pneumophila modulates host cell functions by secreting multiple effectors with diverse biochemical activities. In particular, effectors of the SidE family interfere with host protein ubiquitination in a process that involves production of phosphoribosyl ubiquitin (PR-Ub). Here, we show that effector LnaB converts PR-Ub into ADP-ribosylated ubiquitin, which is further processed to ADP-ribose and functional ubiquitin by the (ADP-ribosyl)hydrolase MavL, thus maintaining ubiquitin homeostasis in infected cells. Upon being activated by actin, LnaB also undergoes self-AMPylation on tyrosine residues. The activity of LnaB requires a motif consisting of Ser, His and Glu (SHxxxE) present in a large family of toxins from diverse bacterial pathogens. Thus, our study sheds light on the mechanisms by which a pathogen maintains ubiquitin homeostasis and identifies a family of enzymes capable of protein AMPylation.

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The reversal of ubiquitination induced by members of the SidE effector family of Legionella pneumophila produces phosphoribosyl ubiquitin (PR-Ub) that is potentially detrimental to host cells. Here we show that the effector LnaB functions to transfer the AMP moiety from ATP to the phosphoryl moiety of PR-Ub to convert it into ADP-ribosylated ubiquitin (ADPR-Ub), which is further processed to ADP-ribose and functional ubiquitin by the (ADP-ribosyl)hydrolase MavL, thus maintaining ubiquitin homeostasis in infected cells. Upon being activated by Actin, LnaB also undergoes self-AMPylation on tyrosine residues. The activity of LnaB requires a motif consisting of Ser, His and Glu (S-HxxxE) present in a large family of toxins from diverse bacterial pathogens. Our study not only reveals intricate mechanisms for a pathogen to maintain ubiquitin homeostasis but also identifies a new family of enzymes capable of protein AMPylation, suggesting that this posttranslational modification is widely used in signaling during host-pathogen interactions.

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The biogenic synthesis of silver nanoparticles (AgNPs) by microorganisms has been a subject of increasing attention. Despite extensive studies on this biosynthetic pathway, the mechanisms underlying the involvement of proteins and enzymes in AgNPs production have not been fully explored. Herein, we reported that Burkholderia contaminans ZCC was able to reduce Ag+ to AgNPs with a diameter of (10±5) nm inside the cell. Exposure of B. contaminans ZCC to Ag+ ions led to significant changes in the functional groups of cellular proteins, with approximately 5.72% of the (C-OH) bonds being converted to (C-C/C-H) (3.61%) and CO (2.11%) bonds, and 4.52% of the CO (carbonyl) bonds being converted to (C-OH) bonds. Furthermore, the presence of Ag+ and AgNPs induced the ability of extracellular electron transfer for ZCC cells via specific membrane proteins, but this did not occur in the absence of Ag+ ions. Proteomic analysis of the proteins and enzymes involved in heavy metal efflux systems, protein secretion system, oxidative phosphorylation, intracellular electron transfer chain, and glutathione metabolism suggests that glutathione S-transferase and ubiquinol-cytochrome c reductase iron-sulfur subunit play importance roles in the biosynthesis of AgNPs. These findings contribute to a deeper understanding of the functions exerted by glutathione S-transferase and ferredoxin-thioredoxin reductase iron-sulfur subunits in the biogenesis of AgNPs, thereby hold immense potential for optimizing biotechnological techniques aimed at enhancing the yield and purity of biosynthetic AgNPs.

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BACKGROUND: We aimed to establish a novel model using a radiomics analysis of magnetic resonance (MR) images for predicting osteoporosis. PURPOSE: To investigate the effectiveness of a radiomics approach utilizing magnetic resonance imaging (MRI) of the lumbar spine in identifying osteoporosis. MATERIAL AND METHODS: In this retrospective study, a total of 291 patients who underwent MRI were analyzed. Radiomics features were extracted from the MRI scans of all 1455 lumbar vertebrae, and build the radiomics model based on T2-weighted (T2W), T1-weighted (T1W), and T2W + T1W imaging. The performance of the combined model was assessed using metrics such as the area under the receiver operating characteristic curve (AUC), sensitivity, specificity, and accuracy. The AUCs of these models were compared using the DeLong test. Their clinical usefulness was assessed using a decision curve analysis. RESULTS: T2W, T1W, and T1W + T2W imaging retained 27, 27, and 17 non-zero coefficients, respectively. The AUCS about radiomics scores based on T2W, T1W, and T1W + T2W imaging were 0.894, 0.934, and 0.945, respectively, which all performed better than the clinical model significantly. The rad-signatures based on T1W + T2W imaging, which exhibited a stronger predictive power, were included in the creation of the nomogram for osteoporosis diagnosis, and the AUC was 0.965 (95% confidence interval (CI)=0.944-0.986) in the training cohort and 0.917 (95% CI=0.738-1.000) in the test cohort. The calibration curve indicated that the radiomics nomogram had considerable clinical usefulness in prediction, observation, and decision curve analysis. CONCLUSION: A reliable and powerful tool for identifying osteoporosis can be provided by the nomogram that combines the T1W and T2W imaging radiomics score with clinical risk factors.

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PURPOSE: To identify the risk factors for training-related lower extremity muscle injuries in young males by a non-invasive method of body composition analysis. METHODS: A total of 282 healthy young male volunteers aged 18 - 20 years participated in this cohort study. Injury location, degree, and injury rate were adjusted by a questionnaire based on the overuse injury assessment methods used in epidemiological studies of sports injuries. The occurrence of training injuries is monitored and diagnosed by physicians and treated accordingly. The body composition was measured using the BodyStat QuadScan 4000 multifrequency Bio-impedance system at 5, 50, 100 and 200 kHz to obtain 4 impedance values. The Shapiro-Wilk test was used to check whether the data conformed to a normal distribution. Data of normal distribution were shown as mean ± SD and analyzed by t-test, while those of non-normal distribution were shown as median (Q1, Q3) and analyzed by Wilcoxon rank sum test. The receiver operator characteristic curve and logistic regression analysis were performed to investigate risk factors for developing training-related lower extremity injuries and accuracy. RESULTS: Among the 282 subjects, 78 (27.7%) developed training injuries. Lower extremity training injuries revealed the highest incidence, accounting for 23.4% (66 cases). These patients showed higher percentages of lean body mass (p = 0.001), total body water (TBW, p = 0.006), extracellular water (p = 0.020) and intracellular water (p = 0.010) as well as a larger ratio of basal metabolic rate/total weight (p = 0.006), compared with those without lower extremity muscle injuries. On the contrary, the percentage of body fat (p = 0.001) and body fat mass index (p = 0.002) were lower. Logistic regression analysis showed that TBW percentage > 65.35% (p = 0.050, odds ratio = 3.114) and 3rd space water > 0.95% (p = 0.045, odds ratio = 2.342) were independent risk factors for lower extremity muscle injuries. CONCLUSION: TBW percentage and 3rd space water measured with bio-impedance method are potential risk factors for predicting the incidence of lower extremity muscle injuries in young males following training.

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A gold-catalyzed, nucleophile-controlled cascade reaction of N-(2-azidophenyl-ynyl)methanesulfonamides with nitriles and water is described that provides structurally diverse 5H-pyrimido[5,4-b]indoles and 2-benzylidene-3-indolinones in good to excellent yields. Mechanistic studies indicate that the ß-sulfonamido-α-imino gold carbene is the key intermediate which is generated through the gold-catalyzed cyclization of N-(2-azidophenyl-ynyl)methanesulfonamides and undergoes formal [4 + 2] cascade annulation with nitriles and intramolecular SN2' type reaction with water, respectively.

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Macrophages are heterogenic phagocytic cells that play distinct roles in physiological and pathological processes. Targeting different types of macrophages has shown potent therapeutic effects in many diseases. Although many approaches are developed to target anti-inflammatory macrophages, there are few researches on targeting pro-inflammatory macrophages, which is partially attributed to their non-s pecificity phagocytosis of extracellular substances. In this study, a novel recombinant protein is constructed that can be anchored on an exosome membrane with the purpose of targeting pro-inflammatory macrophages via antigen recognition, which is named AnCar-ExoLaIMTS . The data indicate that the phagocytosis efficiencies of pro-inflammatory macrophages for different AnCar-ExoLaIMTS show obvious differences. The AnCar-ExoLaIMTS3 has the best targeting ability for pro-inflammatory macrophages in vitro and in vivo. Mechanically, AnCar-ExoLaIMTS3 can specifically recognize the leucine-rich repeat domain of the TLR4 receptor, and then enter into pro-inflammatory macrophages via the TLR4-mediated receptor endocytosis pathway. Moreover, AnCar-ExoLaIMTS3 can efficiently deliver therapeutic cargo to pro-inflammatory macrophages and inhibit the synovial inflammatory response via downregulation of HIF-1α level, thus ameliorating the severity of arthritis in vivo. Collectively, the work established a novel gene/drug delivery system that can specifically target pro-inflammatory macrophages, which may be beneficial for the treatments of arthritis and other inflammatory diseases.

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Retinitis pigmentosa (RP) is the most common type of inherited retinal dystrophy. The course of RP is irreversible and leads to progressive loss of vision. It is characterized by hypotrophic degeneration of photoreceptor cells and retinal pigment epithelium. Multiple factors are involved in the development of the disease, including apoptosis, oxidative stress, and inflammatory/immune responses. In the past decades, gene therapy, stem cell therapy and other therapeutic approaches have been extensively investigated. However, due to the heritability and high heterogeneity of the disease and the difficulty in diagnosis and treatment, there is still a lack of standardized and effective therapies. Therefore, there is a need to develop new diagnostic and therapeutic approaches suitable for diseases with pathogenic mutations. With the understanding of the interaction between gene expression regulation and retinal pathology, the value of clinical applications of non-coding RNAs (ncRNAs) in retinal degeneration has gained attention. There is growing evidence that ncRNAs are widely distributed and involved in the regulation of multiple biological processes in the retina as well as processes associated with the development of RP, making them promising biomarkers for the diagnosis, treatment, and prognosis of RP. This paper reviews the crosstalk between ncRNA and RP, systematically discusses the role of ncRNAs in normal retinal cell physiology and RP pathogenesis and explores the potential of ncRNAs as therapeutic agents for clinical applications in RP.

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As a stressor, cardiac surgery affects the physiology and psychology of patients, as well as their postoperative recovery. Patients tend to worry about cognitive deficiency, pain, discomfort, the risk of death, sleep, complications, and other factors, resulting in stress and anxiety. Moreover, serious adverse events, such as circulatory and respiratory dysfunction and infection, tend to occur after cardiac surgery and increase the economic burden on patients. Therefore, appropriate nursing interventions should be selected to strengthen patients' cognitive levels, compliance, and postoperative practices to accelerate their recovery, reduce complications, and shorten hospital stays so as to contribute to patients' lives and health.

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Natural gas plays a crucial role in daily and industrial production, but the impurities contained in natural gas limit its further use. It is very important to develop adsorbents that can separate CH4 from multicomponent mixtures, but there are still many challenges and problems. Herein, a novel porous MOF {[Mn5(pbdia)2(CO3)(H2O)2] ↔ 5H2O ↔ 2DMF}n (pbdia = 2,2'-(5-carboxy-1,3-phenylene)bis(oxy) diterephthalic acid) was successfully synthesized based on a flexible pentacarboxylic acid ligand and a unique pentanuclear Mn5(COO)10CO3 cluster. The MOF reveals a 3D porous structure with 2D intersecting channels, which shows high C3H8, C2H6, and CO2 adsorption capacities and affinities over CH4. Moreover, the ideal adsorption solution theory selectivities of C3H8/CH4, C2H6/CH4, and CO2/CH4 can reach 263.0, 27.0, and 7.7, respectively, suggesting a potential for removing the low content of C3H8, C2H6, and CO2 from pipeline natural gas, which was further confirmed by breakthrough curves and GCMC simulations.

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Microbial nitrogen fixation is a fundamental process in the nitrogen cycle, providing a continuous supply of biologically available nitrogen essential for life. In this study, we combined cerium oxide-doped carbon dots (CeO2/CDs) with electroactive nitrogen-fixing bacterium Azospirillum humicireducens SgZ-5T to enhance nitrogen fixation through ammonium production. Our research demonstrates that treatment of SgZ-5T cells with CeO2/CDs (0.2 mg mL-1) resulted in a 265.70% increase in ammonium production compared to SgZ-5T cells alone. CeO2/CDs facilitate electron transfer in the biocatalytic process, thereby enhancing nitrogenase activity. Additionally, CeO2/CDs reduce the concentration of reactive oxygen species in SgZ-5T cells, leading to increased ammonium production. The upregulation of nifD, nifH and nifK gene expression upon incorporation of CeO2/CDs (0.2 mg mL-1) into SgZ-5T cells supports this observation. Our findings not only provide an economical and environmentally friendly approach to enhance biological nitrogen fixation but also hold potential for alleviating nitrogen fertilizer scarcity.

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Diabetic retinopathy (DR) is a severe microvascular complication of diabetes mellitus and a major cause of blindness in young adults. Multiple potential factors influence DR; however, the exact mechanisms are poorly understood. Advanced treatments for DR, including laser therapy, vitrectomy, and intraocular drug injections, slow the disease's progression but fail to cure or reverse visual impairment. Therefore, additional effective methods to prevent and treat DR are required. The biological clock plays a crucial role in maintaining balance in the circadian rhythm of the body. Poor lifestyle habits, such as irregular routines and high-fat diets, may disrupt central and limbic circadian rhythms. Disrupted circadian rhythms can result in altered glucose metabolism and obesity. Misaligned central and peripheral clocks lead to a disorder of the rhythm of glucose metabolism, and chronically high sugar levels lead to the development of DR. We observed a disturbance in clock function in patients with diabetes, and a misaligned clock could accelerate the development of DR. In the current study, we examine the relationship between circadian rhythm disorders, diabetes, and DR. We conclude that: 1) abnormal function of the central clock and peripheral clock leads to abnormal glucose metabolism, further causing DR and 2) diabetes causes abnormal circadian rhythms, further exacerbating DR. Thus, our study presents new insights into the prevention and treatment of DR.

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Alzheimer's disease (AD) is a progressive neurodegenerative disease that worsens with age. Long non-coding RNAs (lncRNAs) dysregulation and its associated competing endogenous RNA (ceRNA) network have a potential connection with the occurrence and development of AD. A total of 358 differentially expressed genes (DEGs) were screened via RNA sequencing, including 302 differentially expressed mRNAs (DEmRNAs) and 56 differential expressed lncRNAs (DElncRNAs). Anti-sense lncRNA is the main type of DElncRNA, which plays a major role in the cis and trans regulation. The constructed ceRNA network consisted of 4 lncRNAs (NEAT1, LINC00365, FBXL19-AS1, RAI1-AS1719) and 4 microRNAs (miRNAs) (HSA-Mir-27a-3p, HSA-Mir-20b-5p, HSA-Mir-17-5p, HSA-Mir-125b-5p), and 2 mRNAs (MKNK2, F3). Functional enrichment analysis revealed that DEmRNAs are involved in related biological functions of AD. The co-expressed DEmRNAs (DNAH11, HGFAC, TJP3, TAC1, SPTSSB, SOWAHB, RGS4, ADCYAP1) of humans and mice were screened and verified by real-time quantitative polymerase chain reaction (qRT-PCR). In this study, we analyzed the expression profile of human AD-related lncRNA genes, constructed a ceRNA network, and performed functional enrichment analysis of DEmRNAs between human and mice. The obtained gene regulatory networks and target genes can be used to further analyze AD-related pathological mechanisms to optimize AD diagnosis and treatment.

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Proteolysis Targeting Chimera (PROTAC) is a type of bifunctional chimeric molecule that can directly degrade the binding proteins through the ubiquitin-proteasome pathway. PROTAC has shown great potential in overcoming drug resistance and targeting undruggable targets. However, there are still many shortcomings that need to be solved urgently, including worse membrane permeability and bioavailability induced by their large molecular weight. Herein, we used intracellular self-assembly strategy to construct tumor-specific PROTACs via small molecular precursors. We developed two types of precursors incorporated with azide and alkyne as biorthogonal groups, respectively. These small precursors with improved membrane permeability could react facilely with each other under the catalysis of copper ions with high concentration in tumor tissues, affording novel PROTACs. These novel intracellular self-assembled PROTACs could effectly induce degradation of VEGFR-2 and EphB4 in U87 cells. Meanwhile, they could also promote apoptosis and block cells in S phase. These tumor-specific intracellular self-assembled PROTACs exhibited high selectivity due to the high concentration of copper content in tumor tissue. Moreover, this new strategy could reduce the molecular weight of PROTACs, as well as improve the membrane permeability. These results will greatly expand the applications of bioorthogonal reaction in discovery of novel PROTACs.

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Bevacizumab is an FDA-approved class of monoclonal antibodies used to inhibit angiogenesis and promote normalization of blood vessels. It is usually combined with chemotherapeutic agents to treat a variety of solid tumors. However, the whole-body toxicities and toxicity associated with chemotherapy greatly limit the clinical use of this combination therapy. Antibody-drug conjugates (ADCs) couple monoclonal antibodies to cytotoxic molecules via a linker, utilizing the high specificity of monoclonal antibodies to tumor surface antigens to act as a "biological missile" to deliver chemotherapeutic drugs to the tumor site. Herein, we designed a bevacizumab-based ADC, Bevacizumab Vedotin, conjugating bevacizumab to the microtubulin inhibitor MMAE via a tissue protease-specific linker. Biological studies showed strong stability and good tumor cell targeting of our constructed ADCs; rapid drug release was achieved in the presence of exogenous histone protease B. In addition, Bevacizumab Vedotin exhibited good anti-proliferative, apoptosis-promoting and cell cycle-stalling effects on glioma (U87), hepatocellular carcinoma (HepG2), and breast cancer (MCF-7) cell lines. Further in vitro assays demonstrated the enhanced anti-migration activity against MCF-7, potent anti-angiogenic effects, and blockade of the VEGF/VEGFR pathway of Bevacizumab Vedotin.

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OBJECTIVE: In this study, we aimed to investigate Bregs, their regulatory effects on Th17/Treg cell balance, and the release of downstream inflammatory factors in a mouse model of low-density lipoprotein receptor (LDLr)-/- + Pristane. METHODS: After the establishment of the mouse model of systemic lupus erythematosus (SLE) complicated with atherosclerosis (AS), 8-week-old LDLr-/- + Pristane mice (n = 10) were included in the SLE + AS group. Furthermore, 8-week-old MRL/lpr and C57 mice were used as the SLE and normal control groups, respectively (n = 10 per group). After feeding the mice a high-fat diet for 14 weeks, peripheral blood and spleen of mice were collected, and Bregs, Th17, and Treg cells and related inflammatory factors were detected by flow cytometry, enzyme-linked immunosorbent assay, and reverse-transcription polymerase chain reaction. RESULTS: The number of Bregs and Tregs in spleen lymphocytes of SLE + AS mice significantly decreased compared with the C57 group (p < .05), whereas the number of Th17 cells significantly increased (p = .000). Furthermore, the proportion of Bregs showed a negative correlation with the Th17/Treg ratio (p = .03). Mice in the SLE + AS group showed higher serum interleukin (IL)-10, IL-17, and tumor necrosis factor-α levels than those in the SLE and C57 groups (p < .05). Furthermore, IL-35 and transforming growth factor (TGF)-ß expression was reduced in the SLE + AS group compared with the C57 group (p < .05). CONCLUSIONS: The proportion of Breg decreases was negatively associated with increased Th17/Treg which was increased in SLE + AS mice, indicating that Bregs may regulate Th17/Treg cell homeostasis and cytokine release via IL-35 and TGF-ß production.

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Proteolysis targeting chimera (PROTAC) is a promising therapeutic modality capable of degrading undruggable proteins and overcoming the shortcomings of traditional inhibitors. However, the molecular weight and pharmaceutical properties of PROTACs fall outside of a reasonable range. To overcome the inherent poor druggability of PROTACs, an intracellular self-assembly strategy based on bio-orthogonal reaction was proposed and applied in this study. Herein, two novel classes of intracellular precursors that can self-assemble into protein degraders through bio-orthogonal reactions were explored, including a novel class of E3 ubiquitin ligase ligands bearing tetrazine (E3L-Tz) and target protein ligands incorporated with norbornene (TPL-Nb). These two types of precursors could spontaneously undergo bio-orthogonal reactions in living cells, affording novel PROTACs. Among these precursors, the biological activities of PROTACs formed by target protein ligand with norbornene group (S4N-1) were more potent than others and degrade VEGFR-2, PDGFR-ß and EphB4. The results demonstrated that a highly specific bio-orthogonal reaction driven intracellular self-assembly strategy in living cells could be utilized to improve the degradation activity of PROTACs.

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Anti-angiogenesis has been proved to be an effective strategy for the treatment of tumors. Anti-angiogenic drugs had achieved certain therapeutic effects. However, drug resistance also gradually emerged and limited the application of angiogenesis inhibitors. Proteolysis Targeting Chimeras (PROTACs) are bifunctional molecules capable of degrading proteins through the ubiquitin-proteasome system (UPS). Compared with traditional inhibitors, they displayed advantages of less dosage, lower toxicity and less resistance. In this study, we designed and synthesized a series of novel PROTACs based on our recently reported multi-targeted angiogenesis inhibitor S5. Preliminary biological evaluation of title PROTACs was carried out in various cell lines. The results indicated that these novel bifunctional PROTACs displayed potential in degrading BRAF protein. Their degradation mechanism showed that the degradation of BRAF by PROTAC-1 was dependent on binding to target proteins and E3 ubiquitin ligase. Our findings provided further evidence that these novel PROTACs could be considered in further application in overcome of clinical resistance of traditional angiogenesis inhibitors.

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