SULF1 expression is increased and promotes fibrosis through the TGF-ß1/SMAD pathway in idiopathic pulmonary fibrosis.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive interstitial lung disease of unknown etiology. Despite the increasing global incidence and poor prognosis, the exact pathogenic mechanisms remain elusive. Currently, effective therapeutic targets and treatment methods for this disease are still lacking. This study tried to explore the pathogenic mechanisms of IPF. We found elevated expression of SULF1 in lung tissues of IPF patients compared to normal control lung tissues. SULF1 is an enzyme that modifies heparan sulfate chains of heparan sulfate proteoglycans, playing a critical role in biological regulation. However, the effect of SULF1 in pulmonary fibrosis remains incompletely understood. Our study aimed to investigate the impact and mechanisms of SULF1 in fibrosis. METHODS: We collected lung specimens from IPF patients for transcriptome sequencing. Validation of SULF1 expression in IPF patients was performed using Western blotting and RT-qPCR on lung tissues. ELISA experiments were employed to detect SULF1 concentrations in IPF patient plasma and TGF-ß1 levels in cell culture supernatants. We used lentiviral delivery of SULF1 shRNA to knock down SULF1 in HFL1 cells, evaluating its effects on fibroblast secretion, activation, proliferation, migration, and invasion capabilities. Furthermore, we employed Co-Immunoprecipitation (Co-IP) to investigate the regulatory mechanisms involved. RESULTS: Through bioinformatic analysis of IPF transcriptomic sequencing data (HTIPF) and datasets GSE24206, and GSE53845, we identified SULF1 may potentially play a crucial role in IPF. Subsequently, we verified that SULF1 was upregulated in IPF and predominantly increased in fibroblasts. Furthermore, SULF1 expression was induced in HFL1 cells following exposure to TGF-ß1. Knockdown of SULF1 suppressed fibroblast secretion, activation, proliferation, migration, and invasion under both TGF-ß1-driven and non-TGF-ß1-driven conditions. We found that SULF1 catalyzes the release of TGF-ß1 bound to TGFßRIII, thereby activating the TGF-ß1/SMAD pathway to promote fibrosis. Additionally, TGF-ß1 induces SULF1 expression through the TGF-ß1/SMAD pathway, suggesting a potential positive feedback loop between SULF1 and the TGF-ß1/SMAD pathway. CONCLUSIONS: Our findings reveal that SULF1 promotes fibrosis through the TGF-ß1/SMAD pathway in pulmonary fibrosis. Targeting SULF1 may offer a promising therapeutic strategy against IPF.

Anlotinib prove to be a potential therapy for the treatment of pulmonary fibrosis complicated with lung adenocarcinoma.

Pulmonary fibrosis is a chronic interstitial fibrosis lung disease with high mortality, which is often complicated with lung cancer. The incidence of IPF complicated with lung cancer is getting higher and higher. At present, there is no consensus on the management and treatment of pulmonary fibrosis patients with lung cancer. There is an urgent need to develop preclinical drug evaluation methods for IPF with lung cancer and potential therapeutic drugs for IPF with lung cancer. The pathogenic mechanism of IPF is similar to that of lung cancer, and the multi-effect drugs with anticancer and anti-fibrosis will have potential value in the treatment of IPF complicated with lung cancer. In this study, we established an animal model of IPF complicated with lung cancer in situ to evaluate the therapeutic effect of the antiangiogenic drug anlotinib. The pharmacodynamic results in vivo showed that anlotinib could significantly improve the lung function of IPF-LC mice, reduce the content of collagen in lung tissue, increase the survival rate of mice, and inhibit the growth of lung tumor in mice. The results of Western blot and immunohistochemical analysis of lung tissue showed that anlotinib significantly inhibited the expression of fibrosis marker protein α-SMA, Collagen I and Fibronectin and tumor proliferation marker protein PCNA in mouse lung tissue, and down-regulated the content of serum tumor marker CEA. Through transcriptome analysis, we found that anlotinib regulates MAPK signal pathway, PARP signal pathway and coagulation cascade signal pathway in lung cancer and pulmonary fibrosis, which all play an important role in lung cancer and pulmonary fibrosis. In addition, there is crosstalk between the signal pathway participated by the target of anlotinib and MAPK, JAK/STAT and mTOR signal pathway. In summary, anlotinib will be a candidate for IPF-LC treatment.

Hsa_circ_0010235 functions as an oncogenic drive in non-small cell lung cancer by modulating miR-433-3p/TIPRL axis.

BACKGROUND: Non-small cell lung cancer (NSCLC) is a threat to human health. Circular RNAs (circRNAs) have been proved to function in NSCLC development. In this study, the role of circRNA hsa_circ_0010235 in NSCLC progression and the possible molecular mechanism were explored. METHODS: Expression of hsa_circ_0010235, miRNA (miR)-433-3p and TOR signaling pathway regulator-like (TIPRL) was examined by quantitative real-time PCR (qRT-PCR). Cell viability and clonogenicity were detected by cell counting kit-8 (CCK-8) assay and colony formation assay, respectively. Flow cytometry was performed to monitor cell apoptosis and cell cycle distribution. Western blot assay was employed to evaluate the protein levels of TIPRL, light chain 3 (LC3)-II/I and p62. Cell metastasis was assessed by Transwell and wound healing assays. The targeted relationship between miR-433-3p and hsa_circ_0010235 or TIPRL was confirmed by dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. Furthermore, the role of hsa_circ_0010235 in vivo was investigated by xenograft assay. RESULTS: Hsa_circ_0010235 and TIPRL were highly expressed in NSCLC tissues and cells, while miR-433-3p was downregulated. Depletion of hsa_circ_0010235 or gain of miR-433-3p repressed proliferation and autophagy but promoted apoptosis in NSCLC cells. Hsa_circ_0010235 sponged miR-433-3p to upregulate TIPRL expression, so as to affect NSCLC development. Hsa_circ_0010235 knockdown also blocked tumor growth in vivo. CONCLUSION: Hsa_circ_0010235 knockdown suppressed NSCLC progression by regulating miR-433-3p/TIPRL axis, affording a novel mechanism of NSCLC progression.

Baicalein inhibits cell growth and increases cisplatin sensitivity of A549 and H460 cells via miR-424-3p and targeting PTEN/PI3K/Akt pathway.

Lung cancer is the leading cause of death in individuals with malignant disease. Non-small-cell lung cancer (NSCLC) is the most common type of lung cancer, and chemotherapy drugs such as cisplatin are the most widely used treatment for this disease. Baicalein is a purified flavonoid compound that has been reported to inhibit cancer cell growth and metastasis and increase sensitization to chemotherapeutic drugs via different pathways. Therefore, we assessed the effects of baicalein on the proliferation, apoptosis and cisplatin sensitivity in the NSCLC A549 and H460 cell lines and determined the pathways through which baicalein exerts its effects. Baicalein was slightly toxic to normal human bronchial NHBE cells but inhibited growth, induced apoptosis and increased cisplatin sensitivity in A549 and H460 cells. Baicalein down-regulated miR-424-3p, up-regulated PTEN expression and down-regulated expression of PI3K and p-Akt in A549 and H460 cells. Dual-luciferase reporter assay demonstrated that PTEN is a target gene of miR-424-3p, and overexpression of miR-424-3p or silencing of PTEN partially attenuated the effects of baicalein on A549 and H460 cells. Taken together, we concluded that baicalein inhibits cell growth and increases cisplatin sensitivity to A549 and H460 cells via down-regulation of miR-424-3p and targeting the PTEN/PI3K/Akt pathway.

Aberrant expression of hsa_circ_0025036 in lung adenocarcinoma and its potential roles in regulating cell proliferation and apoptosis.

As the most common histological subtype of lung cancer, lung adenocarcinoma remains a tremendous risk to public health, which requires ceaseless efforts to elucidate the potential diagnostic and therapeutic strategies. Circular RNAs (circRNAs) have been identified with emerging roles in tumorigenesis and development. Our preliminary work noticed that hsa_circ_0025036 was significantly upregulated in lung adenocarcinoma tissues. However, its specific roles in lung adenocarcinoma remain unclear. The results in this study revealed that hsa_circ_0025036 existed as a circular form and was aberrantly upregulated in lung adenocarcinoma tissues via quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Its expression level exhibited a close link with aggressive clinicopathological parameters including cancer differentiation, TNM stage and lymph node metastasis. hsa_circ_0025036 knockdown significantly suppressed cell proliferation and promoted cell apoptosis in A549 and Calu-3 cells. Moreover, hsa_circ_0025036/miR-198/SHMT1&TGF-α axis was identified via bioinformatics analysis and Dual-Luciferase Reporter assays. miR-198 inhibitors reversed the function of hsa_circ_0025036 knockdown. hsa_circ_0025036 knockdown exerted similar effects with miR-198 upregulation on cell proliferation and apoptosis. In conclusion, we demonstrate that hsa_circ_0025036 regulates cell proliferation and apoptosis in lung adenocarcinoma cells probably via hsa_circ_0025036/miR-198/SHMT1&TGF-α axis. hsa_circ_0025036 may serve as a potential prognostic biomarker and a therapeutic target for lung adenocarcinoma.

Long Non-Coding RNA XLOC_008466 Functions as an Oncogene in Human Non-Small Cell Lung Cancer by Targeting miR-874.

BACKGROUND: The therapy and prognosis of lung cancer are difficult because of multiple genetic and epigenetic alterations. Long non-coding RNAs (lncRNAs) have been verified as new mediators of cancer development and progression by virtue of their various functions. Here, we focused on the lncRNA XLOC_008466 based on previous microarray data. However, whether aberrant expression of XLOC_008466 in human non-small cell lung cancer (NSCLC) is correlated with malignancy, metastasis or prognosis has not been elucidated. METHODS: We performed real-time PCR, CCK-8, flow cytometry, trans-well, western blotting, luciferase reporter assays, RNA immunoprecipitation (RIP) assay and surface plasmon resonance (SPR) assay to detect the function of XLOC_008466 in NSCLC. RESULTS: Up-regulation of XLOC_008466 in NSCLC patients was related to lymph node metastasis and the TNM stage. In vitro, down-regulation of XLOC_008466 inhibited cell proliferation and invasion of A549 and H460 cells in vitro, but promoted cell apoptosis. Experiments on mechanisms revealed that XLOC_008466 functioned as a ceRNA, directly binding to miR-874, and could affect cell proliferation, apoptosis and invasion through regulation of miR-874 expression as well as by increasing matrix metalloproteinase 2 (MMP2) and X-linked inhibitor of apoptosis (XIAP) expression. CONCLUSIONS: XLOC_008466 functions as an oncogene in NSCLC by regulating the miR-874-MMP2/XIAP axis, which indicates that XLOC_008466 may be a useful marker and potential therapeutic target in NSCLC.

Overexpression of miR-519d in lung adenocarcinoma inhibits cell proliferation and invasion via the association of eIF4H.

Lung cancer is one of the deadliest types of cancer worldwide due to its high mortality rate. Adenocarcinoma constitutes 20%-30% of all lung cancers. In recent years, studies on the mechanisms of lung tumorigenesis and development have in part focused on the microRNAs for their crucial role in the progress of different cancers. As for our study, we demonstrated that miR-519d was differently downregulated and eIF4H was significantly overexpressed in lung adenocarcinoma via the detection of quantitative real-time polymerase chain reaction compared with the adjacent normal tissues. Furthermore, Cell Counting Kit-8 assay, colony formation assay, xenograft tumor experiment, Ki67 immunohistochemistry assay and transwell assay were performed to explain that the upregulated miR-519d could inhibit the proliferation and invasion of A549 and H1299 cells. To further advance our understanding of the mechanisms of miR-519d, we performed the bioinformatics analysis and the luciferase report assay. The results from these procedures revealed eIF4H to be one of the targets of miR-519d. Downregulated eIF4H was analogous to the overexpressed miR-519d obtained from miR-519d agomir and si-eIF4H transfection. In summary, it can be concluded that miR-519d targets eIF4H in lung adenocarcinoma to inhibit cell proliferation and invasion. This mechanism may offer new insights into the tumorigenesis and development of lung adenocarcinoma.

MicroRNA-338-3p suppresses cell proliferation and induces apoptosis of non-small-cell lung cancer by targeting sphingosine kinase 2.

BACKGROUND: Lung cancer is the major cause of cancer-related death worldwide, and 80% patients of lung cancer are non-small-cell lung cancer (NSCLC) cases. MicroRNAs are important gene regulators with critical roles in diverse biological processes, including tumorigenesis. Studies indicate that sphingosine kinase 2 (SphK2) promotes tumor progression in NSCLC, but how this occurs is unclear. Thus, we explored the effect of miR-338-3p targeting SphK2 on proliferation and apoptosis of NSCLC cells. METHODS: Expression of miR-338-3p and SphK2 in NSCLC A549 and H1299 cell lines was measured using qRT-PCR and Western blot. CCK-8 and colony formation assays were used to assess the effect of miR-338-3p on NSCLC cell line proliferation. Flow cytometry was used to study the effect of miR-338-3p on NSCLC apoptosis. Luciferase reporter assay and Western blot were used to confirm targeting of SphK2 by miR-338-3p. Finally, in vivo tumorigenesis studies were used to demonstrate subcutaneous tumor growth. RESULTS: miR-338-3p expression in 34 NSCLC clinical samples was downregulated and this was correlated with TNM stage. miR-338-3p significantly suppressed proliferation and induced apoptosis of NSCLC A549 and H1299 cells in vitro. SphK2 was a direct target of miR-338-3p. Overexpression of miR-338-3p significantly inhibited SphK2 expression and reduced luciferase reporter activity containing the SphK2 3'-untranslated region (3'-UTR) through the first binding site. SphK2 lacking 3'-UTR restored the effects of miR-338-3p on cell proliferation inhibition. miR-338-3p significantly inhibited tumorigenicity of NSCLC A549 and H1299 cells in a nude mouse xenograft model. CONCLUSIONS: Collectively, miR-338-3p inhibited cell proliferation and induced apoptosis of NSCLC cells by targeting and down-regulating SphK2, and miR-338-3p could inhibit NSCLC cells A549 and H1299 growth in vivo, suggesting a potential mechanism of NSCLC progression. Therapeutically, miR-338-3p may serve as a potential target in the treatment of human lung cancer.

Epigenetic regulation of human FOXP3+ Tregs: from homeostasis maintenance to pathogen defense.

Regulatory T cells (Tregs), characterized by the expression of Forkhead Box P3 (FOXP3), constitute a distinct subset of T cells crucial for immune regulation. Tregs can exert direct and indirect control over immune homeostasis by releasing inhibitory factors or differentiating into Th-like Treg (Th-Treg), thereby actively contributing to the prevention and treatment of autoimmune diseases. The epigenetic regulation of FOXP3, encompassing DNA methylation, histone modifications, and post-translational modifications, governs the development and optimal suppressive function of Tregs. In addition, Tregs can also possess the ability to maintain homeostasis in diverse microenvironments through non-suppressive mechanisms. In this review, we primarily focus on elucidating the epigenetic regulation of Tregs as well as their multifaceted roles within diverse physiological contexts while looking forward to potential strategies involving augmentation or suppression of Tregs activity for disease management, particularly in light of the ongoing global COVID-19 pandemic.

[Retracted] Overexpression of miR­203 increases the sensitivity of NSCLC A549/H460 cell lines to cisplatin by targeting Dickkopf­1.

Following the publication of this paper, it was drawn to the Editors' attention by a concerned reader that certain of the mouse images shown in Fig. 5A and the flow cytometric assay data shown in Fig. 4A and B were strikingly similar to data appearing in different form in other articles written by some of the same authors, but which had already been published elsewhere or were already under consideration for publication, prior to this paper's submission to Oncology Reports. In view of the fact that these apparent duplications of data have come to light, the Editor of Oncology Reports has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive a satisfactory reply. The Editor apologizes to the readership for any inconvenience caused. [Oncology Reports 37: 2129­2136, 2017; 10.3892/or.2017.5505].

[Retracted] miR­125a­5p upregulation suppresses the proliferation and induces the cell apoptosis of lung adenocarcinoma by targeting NEDD9.

Following the publication of this paper, it was drawn to the Editors' attention by a concerned reader that certain of the Transwell invasion assay data panels shown in Fig. 3A were strikingly similar to data appearing in different form in other articles written by different authors, but which had already been published elsewhere prior to this paper's submission to Oncology Reports. In view of the fact some of these data had already apparently been published previously, the Editor of Oncology Reports has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive a reply. The Editor apologizes to the readership for any inconvenience caused. [Oncology Reports 38: 1790­1796, 2017; 10.3892/or.2017.5812].

Long non-coding RNA DSCAS regulates cisplatin sensitivity in lung squamous cell carcinoma by competitively binding to miR-646-3p.

Background: Platinum-based chemotherapy is the main treatment for advanced lung squamous cell carcinoma (LUSC). Eventually, patients with LUSC develop resistance to cisplatin, which affects the prognosis. Hence, the researchers sought to find a lncRNA in LUSC that affects resistance to cisplatin. Methods: The lncRNA microarray assay was used to screen the differential expression of lncRNA. qPCR was used to detect lncRNA DSCAS (DSCAS) expression in tissues and cell lines. Lentiviral transfection was used to regulate the expression of DSCAS. CCK-8, colony formation, wound healing, transwell, and flow cytometry assays were used to assess the biological behaviors and sensitivity to cisplatin of LUSC cell. RNA-RNA interaction was tested using the dual luciferase reporting assay, RNA-IP, and RNA-RNA pull-down assay. The downstream pathway of DSCAS was verified by qPCR and Western blotting assays. Results: DSCAS was highly expressed in LUSC tissues and cells, and its expression levels were higher in cisplatin-insensitive tissues than in cisplatin-sensitive tissues. Elevation of DSCAS promoted cell proliferation, migration and invasion as well as increased cisplatin resistance of lung cancer cells, while demotion of DSCAS inhibited cell proliferation, migration and invasion as well as decreased the cisplatin resistance of lung cancer cells. DSCAS bound to miR-646-3p to regulate the expression of Bcl-2 and Survivin, which affected the cell apoptosis and sensitivity to cisplatin in LUSC cells. Conclusions: DSCAS regulates biological behavior and cisplatin sensitivity in LUSC cells by competitively binding to miR-646-3p to mediate the expression of Survivin and Bcl-2, known as apoptosis-related proteins.

[Evaluation of Efficacy and Prognosis Analysis of Stage III-IV SMARCA4-deficient 
Non-small Cell Lung Cancer Treated by PD-1 Immune Checkpoint Inhibitors plus 
Chemotherapy and Chemotherapy].

BACKGROUND: The SMARCA4 mutation has been shown to account for at least 10% of non-small cell lung cancer (NSCLC). In the present, conventional radiotherapy and targeted therapy are difficult to improve outcomes due to the highly aggressive and refractory nature of SMARCA4-deficient NSCLC (SMARCA4-DNSCLC) and the absence of sensitive site mutations for targeted drug therapy, and chemotherapy combined with or without immunotherapy is the main treatment. Effective SMARCA4-DNSCLC therapeutic options, however, are still debatable. Our study aimed to investigate the efficacy and prognosis of programmed cell death 1 (PD-1) immune checkpoint inhibitors (ICIs) in combination with chemotherapy and chemotherapy in patients with stage III-IV SMARCA4-DNSCLC. METHODS: 46 patients with stage III-IV SMARCA4-DNSCLC were divided into two groups based on their treatment regimen: the chemotherapy group and the PD-1 ICIs plus chemotherapy group, and their clinical data were retrospectively analyzed. Efficacy assessment and survival analysis were performed in both groups, and the influencing factors for prognosis were explored for patients with SMARCA4-DNSCLC. RESULTS: Male smokers are more likely to develop SMARCA4-DNSCLC. There was no significant difference in the objective response rate (76.5% vs 69.0%, P=0.836) between chemotherapy and the PD-1 ICIs plus chemotherapy or the disease control rate (100.0% vs 89.7%, P=0.286). The one-year overall survival rate in the group with PD-1 ICIs plus chemotherapy was 62.7%, and that of the chemotherapy group was 46.0%. The difference in median progression-free survival (PFS) between the PD-1 ICIs plus chemotherapy group and the chemotherapy group was statistically significant (9.3 mon vs 6.1 mon, P=0.048). The results of Cox regression analysis showed that treatment regimen and smoking history were independent influencing factors of PFS in patients with stage III-IV SMARCA4-DNSCLC, and family history was an individual influencing factor of overall survival in patients with stage III-IV SMARCA4-DNSCLC. CONCLUSIONS: Treatment regimen may be a prognostic factor for patients with SMARCA4-DNSCLC, and patients with PD-1 ICIs plus chemotherapy may have a better prognosis.

Piperlongumine inhibits the growth of non-small cell lung cancer cells via the miR-34b-3p/TGFBR1 pathway.

BACKGROUND: Non-small cell lung cancer is a common type of lung cancer. Piperlongumine (PL), which is extracted from the roots of piperaceae plant, long pepper, and peppercorn, is an alkaloid amide that inhibits tumor growth and metastasis. However, whether it affects lung cancer cells remains unclear. METHODS: We assessed the effects of PL on the proliferation and apoptosis of A549 and H1299 NSCLC cell lines. RESULTS: PL was mildly toxic to normal human bronchial epithelial cells and significantly suppressed growth and facilitated apoptosis of A549 and H1299 cells. It also upregulated microRNA (miR)-34b-3p and downregulated the transforming growth factor beta type I receptor (TGFBR1). The dual-luciferase reporter assay showed that TGFBR1 is a target gene of miR-34b-3p. Silencing of miR-34b-3p or overexpression of TGFBR1 partially attenuated the effects of PL on A549 and H1299 cells. CONCLUSIONS: PL inhibits proliferation and induces apoptosis of A549 and H1299 cells by upregulating miR-34b-3p and modulating TGFBR1 signaling pathway.

The efficacy of probiotics in patients with severe COVID-19.

BACKGROUND: To examine the incidence of diarrhea in severe and critical coronavirus disease 2019 (COVID-19) patients, and to observe the efficacy and prognosis of probiotic use in such patients. METHODS: A retrospective study was conducted to investigate the symptoms and incidence of diarrhea in 156 cases of COVID-19 confirmed by the First Affiliated Hospital of Zhengzhou University and the Xinyang Fifth People's Hospital, China. A total of 58 cases of severe and critical COVID-19 were identified and divided into the treatment group or the control group. The control group was given standard treatment according to the Protocols for Diagnosis and Treatment of COVID-19: Prevention, Control, Diagnosis and Management. Patients in the treatment group were administered oral probiotics as well as the standard treatment. The 2 groups were compared in terms of nutritional status (serum albumin), improvement of diarrhea symptoms, changes in inflammatory condition [procalcitonin (PCT) and C-reactive protein (CRP)], the time taken to register a negative result for respiratory tract pathogens on the nucleic acid test, and changes to white blood cell and lymphocyte cell counts. RESULTS: In this study cohort, diarrhea was detected in 15.38% (24/156) of COVID-19 patients. The incidence of diarrhea in patients with mild and moderate COVID-19 was approximately 8.16% (8/98), and the incidence of diarrhea in severe and critically ill patients was approximately 27.59% (16/58). In patients with severe and critical COVID-19, probiotic treatment obviously shortened the duration of diarrhea. Furthermore, compared with the control group, patients treated with probiotics showed a significantly reduced time to achieving a negative nucleic acid test and the inflammation indexes including PCT and CRP were significantly reduced (P<0.05). CONCLUSIONS: The incidence of diarrhea in severe and critically ill COVID-19 patients was significantly higher than that in patients with mild and moderate COVID-19. Probiotics may have a good supporting role in the treatment of patients with COVID-19 and its early application is recommended.

A structural model of a Ras-Raf signalosome.

The protein K-Ras functions as a molecular switch in signaling pathways regulating cell growth. In the human mitogen-activated protein kinase (MAPK) pathway, which is implicated in many cancers, multiple K-Ras proteins are thought to assemble at the cell membrane with Ras effector proteins from the Raf family. Here we propose an atomistic structural model for such an assembly. Our starting point was an asymmetric guanosine triphosphate-mediated K-Ras dimer model, which we generated using unbiased molecular dynamics simulations and verified with mutagenesis experiments. Adding further K-Ras monomers in a head-to-tail fashion led to a compact helical assembly, a model we validated using electron microscopy and cell-based experiments. This assembly stabilizes K-Ras in its active state and presents composite interfaces to facilitate Raf binding. Guided by existing experimental data, we then positioned C-Raf, the downstream kinase MEK1 and accessory proteins (Galectin-3 and 14-3-3σ) on and around the helical assembly. The resulting Ras-Raf signalosome model offers an explanation for a large body of data on MAPK signaling.

GTP hydrolysis is modulated by Arg34 in the RASopathy-associated KRASP34R.

RAS proteins are commonly mutated in cancerous tumors, but germline RAS mutations are also found in RASopathy syndromes such as Noonan syndrome (NS) and cardiofaciocutaneous (CFC) syndrome. Activating RAS mutations can be subclassified based on their activating mechanisms. Understanding the structural basis for these mechanisms may provide clues for how to manage associated health conditions. We determined high-resolution X-ray structures of the RASopathy mutant KRASP34R seen in NS and CFCS. GTP and GDP-bound KRASP34R crystallized in multiple forms, with each lattice consisting of multiple protein conformations. In all GTP-bound conformations, the switch regions are not compatible with GAP binding, suggesting a structural mechanism for the GAP insensitivity of this RAS mutant. However, GTP-bound conformations are compatible with intrinsic nucleotide hydrolysis, including one that places R34 in a position analogous to the GAP arginine finger or intrinsic arginine finger found in heterotrimeric G proteins, which may support intrinsic GTP hydrolysis. We also note that the affinity between KRASP34R and RAF-RBD is decreased, suggesting another possible mechanism for dampening of RAS signaling. These results may provide a foothold for development of new mutation-specific strategies to address KRASP34R -driven diseases.

[Effectiveness of convalescent plasma for treatment of coronavirus disease 2019 patients].

OBJECTIVE: To evaluate the effectiveness and safety of convalescent plasma therapy in patients with severe and critical coronavirus disease 2019 (COVID-19). METHODS: Plasma of 200-400 mL was collected from convalescent patients 2 weeks after being discharged from the hospital. After viral nucleic acid testing and antibody testing, the plasma was infused into 16 severe or critical COVID-19 patients. Time for viral nucleic acid amplification (NAA) test turning negative, total volume of plasma transfusion, average antibody concentration, and total antibody amount were recorded. White blood cell (WBC) counts, lymphocyte (LYM) counts, neutrophil (NEU) counts, alanine aminotransferase (ALT), aspartate aminotransferase (AST), C-reactive protein (CRP), procalcitonin (PCT), lactate dehydrogenase (LDH), creatine kinase (CK), creatine kinase isoenzyme (CK-MB), hypersensitive cardiac troponin T (hs-cTnT), and lactic acid (Lac) levels were measured and the rate of change was calculated at the baseline (d0) before plasma transfusion, and day 1 (d1), day 3 (d3) after transfusion. RESULTS: (1) Patient characteristics: among the 16 patients, 5 cases (31.25%) were severe COVID-19, and 11 cases (68.75%) were critical COVID-19; 62.50% (10/16) of the patients had primary disease; the percentage of invasive ventilation and use of extracorporeal membrane pulmonary oxygenation (ECMO) in critical patients were 90.91% (10/11) and 45.46% (5/11) respectively. (2) Antibody concentration of convalescent plasma and time for NAA test turning negative: the convalescent plasma antibody concentration in this study was ranged from 10.93 kAU/L to 114.7 kAU/L, with an average value of (56.44±39.40) kAU/L. NAA test was continuously positive before plasma transfusion in 10 patients, and the time for NAA test turning negative could be counted. Eight patients turned negative from day 2 to day 8 after transfusion. Severe patients showed a shorter time for NAA test turning negative than critical patients after transfusion [2 (2-3) vs. 5 (3-8), P = 0.036]. Two critical patients transfused plasma with lower antibody concentration remained a positive result of NAA test, and died on the 3rd and 6th day respectively. (3) Laboratory results: the change rates of WBC (0.81±0.28 vs. 1.00) and NEU (0.75±0.33 vs. 1.00) were significantly decreased at d1 after convalescent plasma treatment (both P < 0.05), and the CRP level decreased to about 63% of that before transfusion (P = 0.017). No adverse events were observed during convalescent plasma transfusion. CONCLUSIONS: Viral NAA test of most patients with COVID-19 who received convalescent plasma transfusion turned negative from day 2 to day 8 after transfusion, and the turning time of severe patients was shorter than that of critical patients. Convalescent plasma therapy can reduce the patients' CRP level, and no adverse events were found during the treatment. The antibody concentration in the convalescent plasma may be one of the factors that affect the time for the nucleic acid turning negative after transfusion. Detection and screening convalescent plasma of high-titer antibody and early application to severe and critical patients are expected to improve the efficacy of convalescent plasma.

Response of antibiotic resistance genes abundance by graphene oxide during the anaerobic digestion of swine manure with copper pollution.

The pollution of various environments with antibiotic resistance genes (ARGs) is an urgent problem that needs to be addressed, especially in heavy metal-polluted environments. This study investigated the responses of ARGs and mobile genetic elements (MGEs) to the addition of graphene oxide (GO) to swine manure containing a high concentration copper during anaerobic digestion. The total copy numbers of ARGs and MGEs were significantly enhanced by the pressure due to Cu. GO significantly decreased the ARG and MGE copy numbers, where the low GO concentration performed better than the high GO concentration. Network analysis showed that most of the ARGs and MGEs co-occurred and they shared the same major potential host bacteria. The contributions of different factors to ARG abundances were assessed by redundancy analysis and MGEs had the most important effect on the fate of ARGs. Thus, GO may reduce the abundance of ARGs mainly by removing MGEs.

High-throughput analysis of the effects of different fish culture methods on antibiotic resistance gene abundances in a lake.

Freshwater lakes are important reservoirs for antibiotic resistance genes (ARGs). In this study, we determined the ARG profiles in water samples from Ying Lake, China, using high-throughput quantitative PCR. The high prevalence of ARGs suggested significant pollution with ARGs in the study area, where the ARG diversity and abundance were greater in an area with box-type fish farming than an area with fenced fish farming. Network analysis indicated the widespread co-occurrence of ARGs and mobile genetic elements. cphA-01, blalMP02, and blaCMY202 were identified as adequate indicator genes for estimating the total ARG abundances. Redundancy analysis indicated that changes in the microbial communities caused by variations in the physicochemical parameters with different fish culture methods mainly determined the ARGs in the lake system. Thus, analyzing the factors that affect ARGs provided novel insights into the mechanisms responsible for the maintenance and propagation of ARGs in a lake.