Resveratrol protects mesangial cells under high glucose by regulating the miR-1231/IGF1/ERK pathway.

Diabetic nephropathy (DN) is one of the complications of diabetes mellitus and the main cause of end-stage renal disease (ESRD), which is a serious threat to human health. In DN, mesangial cells (MCs) are a critical target cell that perform a variety of key functions, and abnormal proliferation of MCs is a common and prominent pathological change in DN. In recent years, the investigation of Chinese medicine interventions for DN has increased significantly in recent years due to the many potential adverse effects and controversies associated with the treatment of DN with Western medicines. In this study, we evaluated the protective effect of resveratrol (RES), an active ingredient known as a natural antioxidant, on HMCs under high glucose and explored its possible mechanism of action. We found that RES inhibited the proliferation of human mesangial cell (HMC) under high glucose and blocked cell cycle progression. In the high glucose environment, RES upregulated miR-1231, reduced IGF1 expression, inhibited the activity of the extracellular signal-regulated kinase (ERK) signaling pathway and reduced levels of the inflammatory factors TNF-α and IL-6. In addition, we found that miR-1231 mimics were synergistically inhibited with RES, whereas miR-1231 inhibitor attenuated the protective effect of RES on HMCs. Thus, our results suggest that the protective effect of RES on HMCs under high glucose is achieved, at least in part, through modulation of the miR-1231/IGF1/ERK pathway. The discovery of this potential mechanism may provide a new molecular therapeutic target for the prevention and treatment of DN, and may also bring new ideas for the clinical research in DN.

Sec1 regulates intestinal mucosal immunity in a mouse model of inflammatory bowel disease.

Inflammatory bowel disease (IBD) is a common immune-mediated condition with its molecular pathogenesis remaining to be fully elucidated. This study aimed to deepen our understanding of the role of FUT2 in human IBD, by studying a new surrogate gene Sec1, a neighboring gene of Fut2 and Fut1 that co-encodes the α 1,2 fucosyltransferase in mice. CRISPR/Cas9 was used to prepare Sec1 knockout (Sec1-/-) mice. IBD was induced in mice using 3% w/v dextran sulphate sodium. Small interfering RNA (siRNA) was employed to silence Sec1 in murine colon cancer cell lines CT26.WT and CMT93. IBD-related symptoms, colonic immune responses, proliferation and apoptosis of colon epithelial cells were assessed respectively to determine the role of Sec1 in mouse IBD. Impact of Sec1 on the expression of death receptor 5 (DR5) and other apoptosis-associated proteins were determined. Sec1 knockout was found to be associated with deterioration of IBD in mice and elevated immune responses in the colonic mucosa. Silencing Sec1 in CT26.WT and CMT93 cells led to greater secretion of inflammatory cytokines IL-1ß, IL-6 and TNF-α. Cell counting kit 8 (CCK8) assay, flow cytometry and TUNEL detection suggested that Sec1 expression promoted the proliferation of colon epithelial cells, inhibited cell apoptosis, reduced cell arrest in G0/G1 phase and facilitated repair of inflammatory injury. Over-expression of DR5 and several apoptosis-related effector proteins was noticed in Sec1-/- mice and Sec1-silenced CT26.WT and CMT93 cells, supporting a suppressive role of Sec1 in cell apoptosis. Our results depicted important regulatory roles of Sec1 in mouse IBD, further reflecting the importance of FUT2 in the pathogenesis of human IBD.

Galangin as a direct inhibitor of vWbp protects mice from Staphylococcus aureus-induced pneumonia.

The surge in multidrug resistance in Staphylococcus aureus (S. aureus) and the lag in antibiotic discovery necessitate the development of new anti-infective strategies to reduce S. aureus infections. In S. aureus, von Willebrand factor-binding protein (vWbp) is not only the main coagulase that triggers host prothrombin activation and formation of fibrin cables but also bridges the bacterial cell wall and von Willebrand factor, thereby allowing S. aureus to bind to platelets and endothelial cells, playing a vital role in pathogenesis of S. aureus infections. Here, we have identified that galangin, a bioactive compound found in honey and Alpinia officinarum Hance, is a potent and direct inhibitor of vWbp by coagulation activity inhibition assay, thermal shift assay and biolayer interferometry assay. Molecular dynamic simulations and verification experiments revealed that the Trp-64 and Leu-69 residues are necessary for the binding of galangin to vWbp. Significantly, galangin attenuated S. aureus virulence in a mouse S. aureus-induced pneumonia model. In addition, we also identified that galangin can enhance the therapeutic effect of latamoxef on S. aureus-induced pneumonia. Taken together, the results suggest that galangin may be used for the development of therapeutic drugs or utilized as adjuvants to combine with antibiotics to combat S. aureus-related infections.

Sodium butyrate exerts antioxidant stress effects and attenuates Aß25-35-induced cytotoxicity in PC12 cells.

Alzheimer's disease (AD), a common neurodegenerative disease, is characterised by the deposition of amyloid-ß (Aß) plaques and neurofibrillary tangles. An increasing number of studies have demonstrated that Aß causes neuronal damage and mitochondrial dysfunction. Herein, we evaluated the neuroprotective effect of sodium butyrate (NaB) against Aß induced neurotoxicity in PC12 cells. The results revealed that 3 mM of NaB promoted the expression of angiotensin-converting enzyme and brain-derived neurotrophic factor, which exert a neuroprotective effect by activating G protein-coupled receptors. Moreover, NaB could significantly improve mitochondrial dysfunction caused by Aß. In conclusion, NaB protected PC12 cells from Aß-induced cell damage, highlighting the potential of NaB in AD treatment.

Combined toxic effects of CBNPs and Pb on rat alveolar macrophage apoptosis and autophagy flux.

Carbon black (CB) and heavy metals are the main components of Particulate Matter (PM). Although the individual toxicities of CB and heavy metals have been extensively studied, the combined toxicity is much less understood. In this study, we choose the nano carbon black (CBNPs) and Pb2+ to simulate fine particles in the atmosphere and study the combined toxic effect on rat alveolar macrophages. The data showed that CBNPs could adsorb Pb2+ to form CBNPs-Pb2+ complex and displayed an altered physical properties by particle characterization. CBNPs-Pb2+ synergistically induced rat alveolar macrophages apoptosis and blocked autophagy flux compared with CBNPs and Pb2+ individually. Consistent with this, CBNPs-Pb2+ could impair the mitochondrial membrane potential (MMP), activate apoptotic signaling pathways, inhibit lysosomal function.

Quercetin protects rats from catheter-related Staphylococcus aureus infections by inhibiting coagulase activity.

Coagulase (Coa) activity is essential for the virulence of Staphylococcus aureus (S aureus), one of the most important pathogenic bacteria leading to catheter-related bloodstream infections (CRBSI). We have demonstrated that the mutation of coagulase improved outcomes in disease models of S aureus CRBSI, suggesting that targeting Coa may represent a novel antiinfective strategy for CRBSI. Here, we found that quercetin, a natural compound that does not affect S aureus viability, could inhibit Coa activity. Chemical biological analysis revealed that the direct engagement of quercetin with the active site (residues Tyr187, Leu221 and His228) of Coa inhibited its activity. Furthermore, treatment with quercetin reduced the retention of bacteria on catheter surfaces, decreased the bacterial load in the kidneys and alleviated kidney abscesses in vivo. These data suggest that antiinfective therapy targeting Coa with quercetin may represent a novel strategy and provide a new leading compound with which to combat bacterial infections.

The toxic effects of benzo[a]pyrene on activated mouse T cells in vitro.

Benzo[a]pyrene (B[a]P) is a polycyclic aromatic hydrocarbon contaminant that is widely present in environmental sources, including food. This study aims to clarify the effects of B[a]P toxicity on activated mouse T cells in vitro. Our results show that B[a]P markedly inhibited Concanavalin A (ConA)-induced T lymphocyte proliferation and suppressed the production of the cytokines Interferon (IFN)-γ, Interleukin (IL)-2 and IL-4. Western blot and protein-DNA interaction assays were used to study how B[a]P affects signal transduction. The results revealed that B[a]P suppressed the ConA-induced activation of the Ca2+/CaM/NFκB and Ca2+/CaM/CaN/NFAT signal transduction pathways. These observations indicate that B[a]P has toxic effects on activated mouse T cells in vitro.

Downregulation of microRNA-637 Increases Risk of Hypoxia-Induced Pulmonary Hypertension by Modulating Expression of Cyclin Dependent Kinase 6 (CDK6) in Pulmonary Smooth Muscle Cells.

BACKGROUND The objective of this study was to investigate the molecular mechanism by which miR-637 interferes with the expression of CDK6, which contributes to the development of pulmonary hypertension (PH) with chronic obstructive pulmonary disease (COPD). MATERIAL AND METHODS We used an online miRNA database to identify CDK6 as a virtual target of miR-637, and validated the hypothesis using luciferase assay. Furthermore, we transfected SMCs with miR-637 mimics and inhibitor, and expression of CDK6 was determined using Western blot and real-time PCR. RESULTS In this study, we identified CDK6 as a target of miR-637 in smooth muscle cells (SMCs), and determined the expression of miR-637 in SMCs from PH patients with COPD and normal controls. We also identified the exact miR-637 binding site in the 3'UTR of CDK6 by using a luciferase reporter system. The mRNA and protein expression levels of CDK6 in SMCs from PH patients with COPD were clearly upregulated compared with the normal controls. Cells exposed to hypoxia also showed notably increased CKD6 mRNA and protein expression levels, and when treated with miR-637 or CDK6 siRNA, this increase in CKD6 expression was clearly attenuated. Additionally, cell viability and cell cycle analysis showed that hypoxia markedly increased viability of SMCs by causing an accumulation in S phase, which was relieved by the introduction of miR-637 or CDK6 siRNA. CONCLUSIONS Our study proved that the CDK6 gene is a target of miR-637, and demonstrated the regulatory association between miR-637 and CDK6, suggesting a possible therapeutic target for PH, especially in patients with COPD.

Pristimerin attenuates ovalbumin-induced allergic airway inflammation in mice.

Pristimerin has been shown to possess antiinflammatory activity. However, its potential use for asthma induced by airway inflammation has not yet been studied. First, we established a ovalbumin (OVA)-induced allergic asthma mice model. BALB/c mice were immunized and challenged by OVA. Treatment with pristimerin caused a marked reduction in the levels of OVA-specific IgE, immune cells, and IL-4, IL-5, IL-13 secretion. Histological studies using H&E staining were used to study the alterations in lung tissue. These results were similar to those obtained with dexamethasone treatment. We then investigated which signal transduction mechanisms could be implicated in pristimerin activity by Western blot. The data showed that pristimerin could inhibit MAPKs and NF-κB inflammatory pathways.

Prognostic value of plasma diquat concentration in patients with acute oral diquat poisoning: a retrospective study.

Objectives: Diquat poisoning is an important public health and social security agency. This study aimed to develop a prognostic model and evaluate the prognostic value of plasma diquat concentration in patients with acute oral diquat poisoning, focusing on how its impact changes over time after poisoning. Methods: This was a retrospective cohort study using electronic healthcare reports from the Second Hospital of Hebei Medical University. The study sample included 80 patients with acute oral Diquat poisoning who were admitted to the hospital between January 2019 and May 2022. Time-to-event analyses were performed to assess the risk of all-cause mortality (30 days and 90 days), controlling for demographics, comorbidities, vital signs, and other laboratory measurements. The prognostic value of plasma DQ concentration on admission was assessed by computing the area under a time-dependent receiver operating characteristic curve (ROC). Results: Among the 80 patients, 29 (36.25%) patients died, and 51 (63.75%) patients survived in the hospital. Non-survivors had a median survival time (IQR) of 1.3(1.0) days and the longest survival time of 4.5 days after DQ poisoning. Compared with non-survivors, survivors had significantly lower amounts of ingestion, plasma DQ concentration on admission, lungs injury within 24 h after admission, liver injury within 24 h after admission, kidney injury within 24 h after admission, and CNS injury within 36 h after admission, higher APACHE II score and PSS within 24 h after admission (all p < 0.05). Plasma Diquat concentration at admission (HR = Exp (0.032-0.059 × ln (t))) and PSS within 24 h after admission (HR: 4.470, 95%CI: 1.604 ~ 12.452, p = 0.004) were independent prognostic factors in the time-dependent Cox regression model. Conclusion: Plasma DQ concentration at admission and PSS within 24 h after admission are independent prognostic factors for the in-hospital case fatality rate in patients with acute oral DQ poisoning. The prognostic value of plasma DQ concentration decreased with time.

Food-Borne Poisoning Accident from Amanitin Toxin in Wild Mushrooms - Xingtai City, Hebei Province, China, 2023.

What is already known about this topic?: Fatal poisonings caused by wild mushrooms containing amanita toxins pose a significant threat in the southern regions of China. These toxins primarily induce gastrointestinal symptoms initially, which are then followed by potentially life-threatening acute liver damage. What is added by this report?: This report contributes to the existing knowledge on these cases of poisoning by documenting the second occurrences in Hebei Province and the first occurrences in Xingtai City. Five individuals reported consuming wild mushrooms from the same origin, and laboratory tests confirmed the presence of α-amanitin in their blood samples. What are the implications for public health practice?: This underscores the risk associated with the collection and consumption of amanita toxin-containing mushrooms in Hebei. It is important to note that the identification of toxic and non-toxic mushrooms should not solely rely on personal experience or appearance.

Biliary hemorrhage caused by a malignant small round cell tumor in the common bile duct: A case report.

BACKGROUND: Malignant small round cell tumor (MSRCT) metastasis to the common bile duct associated with recurrent biliary hemorrhage is extremely rare. Thus far, there have been no reports of metastatic small round cell tumors of the common bile duct. CASE SUMMARY: Herein, we report the case of a 77-year-old female patient with an MSRCT in the common bile duct. The patient was admitted to hospital due to gastrointestinal hemorrhage and abdominal pain. We found a neoplasm in the common bile duct with active bleeding through a spyglass. We performed biopsy through the spyglass and placed a metal stent to stop bleeding. The pathological result suggested that it was an MSRCT metastasized from the back to the common bile duct. Later, we found using fluorescence in situ hybridization that the SS18 gene break test was negative, ruling out the diagnosis of synovial sarcoma. CONCLUSION: MSRCT is a group of tumors with similar cell morphology and diffuse histological structure. Complete tumor resection results in improved survival in patients with MSRCT. Roux-en-Y cholangiojejunostomy was performed. After excision of the common bile duct tumor, the patient felt that the abdominal pain improved and hemorrhage disappeared. The patient underwent routine fecal examination one month after surgery, indicating a negative fecal occult blood test. On May 22, 2023, the patient was reexamined by abdominal computed tomography, and no abdominal space occupying lesions or abdominal lymphadenopathy was found.

Shenkang protects renal function in diabetic rats by preserving nephrin expression.

BACKGROUND: Shenkang injection has been used clinically to lower creatinine levels. This study explored the mechanism of Shenkang injection on protecting kidney function from hyperglycemia-mediated damage. METHODS: This study utilized a STreptoZotocin (STZ)-induced rat model of diabetes. In total, 60 rats were randomized into either the control group (n = 15) injected with vehicle or treatment group (n = 45) injected with STZ to induce hyperglycemia. Eight weeks after diabetes onset, diabetic rats were further randomized to receive different treatments for 4 consecutive weeks, including vehicle (diabetic nephropathy group, n = 15), Shenkang (n = 15), or Valsartan (n = 15). At 12 weeks, a series of urine and blood measures were examined and damage to the kidney tissue was examined using histology. Expression of nephrin and transforming growth factor-ß1 (TGF-ß1) were characterized using immunohistochemistry and Western blot. RESULTS: Compared to the control group, rats in the diabetic nephropathy group showed significant kidney damage demonstrated by high kidneyindex, high levels of urinary albumin, albumin/creatinine ratio (ACR), blood urea nitrogen as well as histological evidence. Shenkang injection significantly improved kidney function in the diabetic rats by decreasing kidney index, ACR, and serum creatinine. Shenkang treatment also mitigated kidney damage, improved nephrin expression, and decreased TGF-ß1 expression in the kidneys. CONCLUSIONS: Shenkang treatment protected renal function in diabetic rats by increasing nephrin expression, which protects diabetic rats from hyperglycemia-mediated kidney damage.

Blockage of nerve growth factor modulates T cell responses and inhibits allergic inflammation in a mouse model of asthma.

OBJECTIVE: Blockage of nerve growth factor (NGF) by anti-NGF antibodies can inhibit allergic airway hyper-responsiveness in mice. This study was aimed at determining the mechanisms underlying the action of anti-NGF in vivo. METHODS: BALB/c mice were sensitized with ovalbumin (OVA) and treated with anti-NGF. At 1 day after the last challenge, their airway responsiveness and inflammation were examined and the levels of cytokine and transcription factor mRNA transcripts in the lungs and cytokines in the bronchoalveolar lavage fluid were determined. The frequency of different functional T cells and the levels of serum OVA-specific antibodies were measured. RESULTS: OVA challenge induced severe airway resistance, inflammation, higher levels of IL-4, TNFα, IL-17A, TGFß, GATA-3 and RORγT expression and increased Th2 and Th17 cells and IgE responses, but decreased IFNγ and IL-10 responses, T-bet and Foxp3 expression and Th1 and Tregs. Treatment with anti-NGF significantly reduced allergic airway resistance and inflammation, up-regulated IFNγ, IL-10, TGFß, T-bet, and Foxp3 expression, increased Th1 and Tregs, but down-regulated IL-4, TNFα, IL-17A, RORγT and GATA-3 expression and reduced Th2 and Th17 cells, accompanied by increased serum IgG2a. CONCLUSIONS: Anti-NGF inhibits allergic airway inflammation by modulating the balance of pro- and anti-asthmatic T cell responses in the lungs of mice.

[Clinical features of 86 cases of acute diquat poisoning].

OBJECTIVE: To explore the clinical features of acute diquat (DQ) poisoning, and further improve the awareness of acute DQ poisoning. METHODS: A retrospective analysis was performed on the clinical data of patients with acute DQ poisoning diagnosed in the emergency department of the Second Hospital of Hebei Medical University from January 1, 2019 to December 31, 2021. The clinical data included age, gender, exposure routes, presence of pesticides (drugs) mixture poisoning, dosage of poison, the time from taking poisoning to admitting in the emergency department, clinical manifestations, laboratory data, treatment, hospital days, prognosis and survival days. RESULTS: The number of cases who firstly complained of acute DQ poisoning in the past three years were 19 cases in 2019, 28 cases in 2020, and 51 cases in 2021. A total of 12 patients were excluded due to being diagnosed paraquat (PQ) poisoning by toxicology detection. Finally, 86 cases of acute DQ poisoning were included, including 80 cases of oral DQ poisoning, 1 case of intramuscular injection, 1 case of binocular contact and 4 cases of dermal exposure. In 80 cases of oral DQ poisoning, there were 70 cases of diquat poisoning alone (42 cases survived, 28 cases died) and 10 cases of pesticide mixture poisoning (6 cases survived, 4 cases died). The time from oral poisoning to admitting in the emergency department was 0.5-96.0 hours, with an average of (8.6±5.8) hours. The time of intramuscular injection poisoning to admitting in the emergency department was 3 hours. The time of dermal exposure to admitting in the emergency department was relatively long, with an average of 66.1 hours. The time from oral simple DQ poisoning to death was 12.0-108.0 hours, and the time from oral mixed DQ poisoning to death was 24.0-576.0 hours. A total of 70 patients with oral diquat poisoning alone presented various degrees of multiple organ injuries. All patients presented gastrointestinal symptoms such as nausea and vomiting. Renal injury and central nervous system injury were the most significant and closely related to the prognosis. CONCLUSIONS: Acute oral DQ poisoning can cause to multiple organ injuries, and the clinical manifestations are related to the dose of the poison. In severe cases, acute renal failure and refractory circulatory failure occur within 24 hours after poisoning, and severe central nervous system injury with disturbance of consciousness as the primary manifestation occurs within 36 hours, followed by multiple organ failure until death.

Influence of TRAIL Deficiency on Th17 Cells and Colonic Microbiota in Experimental Colitis Mouse Model.

BACKGROUND: The abnormalities of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) are implicated in various autoimmune disorders and tumors. This study investigated the influence of TRAIL deficiency on Th17 cells and colonic microbiota in experimental colitis mouse model. METHODS: Mice were randomly divided into 4 groups: wild-type, TRAIL gene knock-out (TRAIL-/-), wild-type colitis and TRAIL-/- colitis groups. Colitis was induced by oral administration of 3.5% dextran sulfate sodium (DSS) for 7 consecutive days. Mice were given scores for disease severity both clinically and histopathologically. Th17 cells in peripheral blood and mesenteric lymph nodes (MLNs) were assessed using flow cytometry. The expression levels of Th17 cell markers IL-17A and ROR-γt were evaluated by quantitative real-time polymerase chain reaction. The colonic samples were also analyzed for microbiota profile by 16s-rDNA gene sequencing on variable V4 region. RESULTS: Compared with wild-type counterparts, TRAIL-/- mice developed more severe colitis after DSS treatment. Colitis TRAIL-/- mice had increased proportion of Th17 cells and elevated mRNA expression levels of IL-17A and ROR-γt in peripheral blood and MLNs compared with colitis wild-type mice. In contrast to colitis wild-type mice, the composition of colonic microbiota was shifted in colitis TRAIL-/- mice, and was characterized by increased alpha diversity, increased TM7, deferribacteres and tenericutes, and decreased proteobacteria at the phylum level. CONCLUSIONS: These findings suggested that TRAIL deficiency not only aggravated DSS-induced colitis, but also led to enhanced Th17 cell response and altered colonic microbiota composition.

Effect of dynamic stratified potassium supplementation in elderly patients with chronic heart failure and moderate to severe hypokalaemia-a randomised, controlled trial.

OBJECTIVE: To compare the effectiveness of dynamic stratified potassium supplementation at high concentrations with enteral potassium supplementation in older patients with chronic heart failure and moderate to severe hypokalaemia. METHODS: We performed a single-centre, short-term, randomised, controlled, open-labelled, clinical trial, and patients were randomly allocated to the control or intervention group. The intervention group received intermittent infusions of 30 mmol/100 mL potassium chloride. In the control group, 10% potassium chloride was administered orally in a bolus dose. Short-term efficacy and adverse events were compared. RESULTS: The intervention group received less potassium than that in the control group. T-wave normalisation and U-wave disappearance occurred sooner in the intervention group than in the control group after potassium supplementation. The rate of increase in potassium concentrations gradually became similar in both groups. The initial blood potassium concentration, method of potassium supplementation, potassium supplement dose, and 24-hour urinary potassium excretion significantly affected the rate of increase in blood potassium concentrations after supplementation. CONCLUSIONS: The efficacy of enteral potassium supplementation is equivalent to that of supplementation with high intravenous potassium concentrations in elderly patients with chronic heart failure and moderate to severe hypokalaemia. High intravenous potassium concentrations may lead to a superior potassium recovery rate.

Cardiogenic shock as the initial manifestation of systemic lupus erythematosus.

Cardiogenic shock as the initial manifestation of systemic lupus erythematosus (SLE) is an uncommon but catastrophic complication. Because of the lack of typical clinical features, the diagnosis of the disease is challenging. This case report describes a 47-year-old female admitted to the emergency room in refractory cardiogenic shock with dilative cardiomyopathy and a left ventricular ejection fraction (LVEF) of 25.6% of unknown origin. The patient responded poorly to the initial tries of stabilization, and the clinical status continued to deteriorate. Venous-arterial extracorporeal membrane oxygenation (V-A ECMO) was applied to maintain hemodynamic stability. Coronary angiography revealed no obvious stenosis of the coronary artery. Evidence of virus infection was negative. After requestioning about medical history in detail, Reynaud's phenomenon was shown. SLE was suspected. A complete autoimmune laboratory workup was completed and found the positive result of antinuclear antibodies, anti-double-stranded DNA antibodies, anti-phospholipid antibodies, and low C3 and C4. The patient also presented with pericardial effusion and the PLTs <100 000/mm3 . SLE was confirmed according to the 2019 EULAR/ACR criteria. When the diagnosis was established, the immunotherapy was initiated. As a result, the patient underwent a quick recovery and achieved good outcomes. In conclusion, early diagnosis and timely application of immunotherapy is the key to treatment lupus myocarditis. Advanced mechanical support may play a necessary role when patient is in critical situation. For middle-aged female patients presenting with unexplained cardiogenic shock, lupus myocarditis should be considered in the differential diagnosis. In addition, the 2019 EULAR/ACR criteria provide a new, fitting tool for the diagnosis, which is conducive to the earlier and more accurate diagnosis of SLE.

Low-Dose Radiation Promotes the Proliferation and Migration of AGE-Treated Endothelial Progenitor Cells Derived from Bone Marrow via Activating SDF-1/CXCR4/ERK Signaling Pathway.

Low-dose radiation (LDR) has been confirmed to mobilize bone marrow-derived endothelial progenitor cells (EPCs) and promote diabetic wound healing. But it is unclear whether LDR acts directly on EPCs and promotes their proliferation and migration. Given the key role of advanced glycosylation end products (AGE) in the pathogenesis of diabetes, we used AGE to induce EPC damage. We then investigated the effect of LDR on the proliferation and migration of AGE-treated EPCs and explored the underlying mechanisms. EPCs cultured in vitro were treated with different concentrations of AGE, and the cells were then exposed to different low doses and treated with a specific antagonist for CXCR4, AMD3100 (1 lmol/l). The proliferation and migration abilities of EPCs were detected using the CCK-8 and wound healing assays, respectively. The mRNA and protein expression of SDF-1 and CXCR4 in AGE-treated EPCs were measured using qPCR and Western blot analysis, respectively. The expressions of ERK and phosphorylated ERK (pERK) were detected using Western blot analysis. The results showed that 200 mg/l and 400 mg/l AGE had an inhibitory effect on the proliferation of EPCs, and this inhibitory effect was exerted in a dose- and time-dependent manner. AGE significantly reduced the migration ability of EPCs cultured in vitro. After the cells received either 50 or 75 mGy low-dose irradiation, the proliferation of EPCs and AGE-treated EPCs was clearly increased; in addition, LDR also enhanced cell migration ability, but this enhancement was counteracted by AMD3100. Results from qPCR and Western blot analysis showed that LDR increased the mRNA and protein expression of SDF-1/ CXCR4. LDR also upregulated pERK expression in EPCs and AGE-treated EPCs, but LDR-induced upregulation of pERK expression was inhibited by AMD3100. These findings indicate that LDR can directly activate the SDF-1/CXCR4 biological axis and downstream ERK signaling pathway, and promote the proliferation and migration abilities of EPCs by increasing the expression of SDF-1, CXCR4 and pERK in EPCs.

An Inhibitory Effect of Dryocrassin ABBA on Staphylococcus aureus vWbp That Protects Mice From Pneumonia.

Von Willebrand factor-binding protein (vWbp), secreted by Staphylococcus aureus (S. aureus), can activate host prothrombin, convert fibrinogen to fibrin clots, induce blood clotting, and contribute to pathophysiology of S. aureus-related diseases, including infective endocarditis, staphylococcal sepsis and pneumonia. Therefore, vWbp is an promising drug target in the treatment of S. aureus-related infections. Here, we report that dryocrassin ABBA (ABBA), a natural compound derived from Dryopteris crassirhizoma, can significantly inhibit the coagulase activity of vWbp in vitro by directly interacting with vWbp without killing the bacteria or inhibiting the expression of the vWbp. Using molecular dynamics simulations, we demonstrate that ABBA binds to the "central cavity" in the elbow of vWbp by interacting with Arg-70, His-71, Ala-72, Gly-73, Tyr-74, Glu-75, Tyr-83, and Gln-87 in vWbp, thus interfering with the binding of vWbp to prothrombin. Furthermore, in vivo studies demonstrated that ABBA can attenuate injury and inflammation of mouse lung tissues caused by S. aureus and increase survival of mice. Together these findings indicate that ABBA is a promising lead drug for the treatment of S. aureus-related infections. This is the first report of potential inhibitor which inhibit the coagulase activity of vWbp by directly interacting with vWbp.