Density Analysis of Adsorption Phase in the Thermodynamic Study of Shale Gas Adsorption.

Understanding the adsorption mechanism and precisely predicting the thermodynamic adsorption properties of methane at high pressure are crucial while very challenging for shale gas development. In this study, we demonstrated that the Langmuir adsorption model combining with different empirical methods to determine the adsorption phase density makes the calculated isothermal adsorption heat violate Henry's law at low pressure. For instance, the isothermal adsorption heat calculated by the Langmuir-Freundlich model contradicts Henry's law when the absolute adsorption quantity is zero. Given the current challenge in accurately calculating the adsorption phase density, it is necessary to impose constraints on the parameters of the adsorption model by adhering to Henry's law to maintain thermodynamic consistency. We found that the adsorption phase volume of methane molecules lies between the micropore volume and the total pore volume when shale adsorption reaches saturation. The adsorption mechanism involves not only filling micropores but also monolayer adsorption in meso-macro pores. The high-energy adsorption sites for methane are primarily concentrated in organic matter, while within these methane adsorption areas in shale, the high-energy adsorption sites for water are mainly located in kaolinite within clay minerals. The zero-pressure heat of adsorption is a temperature-independent thermodynamic index, yet it is influenced by the water content. It can therefore be selected as a quantitative measure to evaluate the impact of methane adsorption on water.

Dietary zinc intake in relation to migraine among adults: a cross sectional study of NHANES 1999-2004.

BACKGROUND: Previous studies have revealed that an antioxidant diet is a protective factor against migraine. However, the association between zinc, an important antioxidant obtained from the diet, and migraine has received little attention. The purpose of this study was to explore the association between zinc intake with migraine. METHODS: The present study used cross-sectional data from individuals who participated in the National Health and Nutrition Examination Survey (NHANES) between 1999 and 2004. Logistic regression models and restricted cubic spline models were performed to explore the association between zinc intake and migraine. RESULTS: A total of 9849 adults aged 20 years or older were included in this study. Zinc intake was negatively associated with migraine. Compared to participants in the lowest group of dietary zinc intake Q1 (≤5.93 mg/day), the adjusted ORs for migraine in Q2 (5.94-8.38 mg/day), Q3 (8.39-11.26 mg/day), Q4 (11.27-15.75 mg/day), and Q5 (≥15.76 mg/day) were 0.73 (95% CI: 0.60-0.89, p = 0.004), 0.72 (95% CI: 0.55-0.95, p = 0.02), 0.76 (95% CI: 0.58-0.99, p = 0.04) and 0.73 (95% CI: 0.50-1.05, p = 0.08), respectively. Our findings also suggested an interaction between zinc intake and age (P for interaction = 0.007). Additionally, the relationship between zinc intake and migraine in adults with 20-50 years was non-linear. CONCLUSIONS: A higher zinc intake is significantly associated with a decreased prevalence of migraine, and age can modify the association between them.

CCR1 enhances SUMOylation of DGCR8 by up-regulating ERK phosphorylation to promote spinal nerve ligation-induced neuropathic pain.

Neuropathic pain is a somatosensory nervous system dysfunction that remains a threatening health problem globally. Recent studies have highlighted the involvement of C-C motif chemokine receptor 1 (CCR1) in neuropathic pain. Herein, the current study set out to explore the modulatory role of CCR1 in spinal nerve ligation (SNL)-induced neuropathic pain and its underlying molecular mechanism. First, it was found that CCR1 was highly expressed in spinal cord tissues and microglial cells of SNL rats. On the other hand, CCR1 knockdown attenuated nerve pain in SNL rats and repressed microglial cell activation in SNL rats and also in the LPS-induced microglial cell model of nerve injury, as evidenced by elevated microglial cell markers OX-42 and IL-1ß, IL-6 and TNF-α. Mechanistically, CCR1 enhanced small ubiquitin-like modifier 1 (SUMO1) modification of DiGeorge syndrome critical region gene 8 (DGCR8) in LPS-treated microglial cells by phosphorylating ERK. Moreover, CCR1 silencing brought about elevations in mechanical withdrawal threshold and thermal withdrawal latency. To conclude, our findings indicated that CCR1 enhanced the modification of DGCR8 by SUMO1 through phosphorylation of ERK, thereby promoting the activation and inflammatory response of spinal cord microglial cells and increasing the sensitivity of SNL rats to pain. Thus, this study offers a promising therapeutic target for the management of neuropathic pain.

Effects of sevoflurane exposure during different stages of pregnancy on the brain development of rat offspring.

OBJECTIVE: This study explored the effects of sevoflurane exposure during different stages of pregnancy on the brain development of offspring. METHODS: Thirty-six pregnant SD rats were randomly divided into 4 groups: control, sevoflurane exposure in early (S1) pregnancy, sevoflurane exposure in middle (S2) pregnancy, and sevoflurane exposure in late (S3) pregnancy. After natural birth, the learning and memory capacity of offspring rats was analyzed using the Morris water maze experiment. The hippocampi of offspring rats were collected. The levels of interleukin (IL)-1ß, IL-6, and tumor necrosis factor (TNF)-α in the hippocampus were measured by ELISA. Additionally, the Nissl bodies in the hippocampus were analyzed using Nissl staining. Immunohistochemistry was used to examine the expression of BDNF and CPEB2 in the hippocampus of offspring. Proteins related to the NR4A1/NF-κB pathway were analyzed using western blotting. RESULTS: The memory and learning capacity of offspring rats was significantly reduced in the S1 and S2 groups compared to the control group (p < 0.05), while there was no obvious difference between the control and S3 groups (p > 0.05). The level of IL-1ß was significantly increased (p < 0.05) in the S1 group compared with the control group. Sevoflurane anesthesia received in early and middle pregnancy could significantly affect the formation of Nissl bodies in the hippocampi of offspring rats. In addition, the expression of BDNF and CPEB2 in the hippocampi of offspring rats was greatly decreased in the S1 group compared with the control group (p < 0.05). The expression of NR4A1 in the hippocampi of rat offspring was significantly decreased in the S1 and S2 groups compared with the control group (p < 0.05). The expression of proteins related to the NF-κB pathway was increased in the S1 group compared to the control group (p < 0.05). CONCLUSIONS: The neurotoxic effect of maternal sevoflurane anesthesia on the brain development of offspring is higher when the exposure occurs in early pregnancy than in late pregnancy, and its mechanism might involve the NR4A1/NF-κB pathway to increase the secretion of inflammatory cytokines.

Notch maintains Drosophila type II neuroblasts by suppressing expression of the Fez transcription factor Earmuff.

Notch signaling is crucial for maintaining neural stem cell (NSC) self-renewal and heterogeneity; however, the underlying mechanism is not well understood. In Drosophila, loss of Notch prematurely terminates the self-renewal of larval type II neuroblasts (NBs, the Drosophila NSCs) and transforms type II NBs into type I NBs. Here, we demonstrate that Notch maintains type II NBs by suppressing the activation of earmuff (erm) by Pointed P1 (PntP1). We show that loss of Notch or components of its canonical pathway leads to PntP1-dependent ectopic Erm expression in type II NBs. Knockdown of Erm significantly rescues the loss-of-Notch phenotypes, and misexpression of Erm phenocopies the loss of Notch. Ectopically expressed Erm promotes the transformation of type II NBs into type I NBs by inhibiting PntP1 function and expression in type II NBs. Our work not only elucidates a key mechanism of Notch-mediated maintenance of type II NB self-renewal and identity, but also reveals a novel function of Erm.

The Ets protein Pointed prevents both premature differentiation and dedifferentiation of Drosophila intermediate neural progenitors.

Intermediate neural progenitors (INPs) need to avoid both dedifferentiation and differentiation during neurogenesis, but the underlying mechanisms are not well understood. In Drosophila, the Ets protein Pointed P1 (PntP1) is required to generate INPs from type II neuroblasts. Here, we investigated how PntP1 promotes INP generation. By generating pntP1-specific mutants and using RNAi knockdown, we show that the loss of PntP1 leads to both an increase in type II neuroblast number and the elimination of INPs. The elimination of INPs results from the premature differentiation of INPs due to ectopic Prospero expression in newly generated immature INPs (imINPs), whereas the increase in type II neuroblasts results from the dedifferentiation of imINPs due to loss of Earmuff at later stages of imINP development. Furthermore, reducing Buttonhead enhances the loss of INPs in pntP1 mutants, suggesting that PntP1 and Buttonhead act cooperatively to prevent premature INP differentiation. Our results demonstrate that PntP1 prevents both the premature differentiation and the dedifferentiation of INPs by regulating the expression of distinct target genes at different stages of imINP development.

Impact of epidural analgesia on quality of life and pain in advanced cancer patients.

Patients with advanced cancer often experience chronic postoperative pain and poor quality of life. The objective of this study was to determine if epidural self-controlled analgesia reduced the incidence of chronic pain and improved the quality of life when compared with intravenous self-controlled analgesia. A total of 50 patients diagnosed with advanced cancer who received analgesia treatment were randomly divided into two groups, epidural self-controlled analgesia group (EA group, n = 26) and intravenous self-controlled analgesia group (IA group, n = 24). Visual analog scale (VAS) and Karnofsky score were used to assess the pain and the quality of life, respectively. A multifunction monitor was used to continuously record the physical signs of patients after treatment. The physical signs, such as heart failure, respiration, pulse, blood pressure, and oxygen saturation, in the two groups were better after analgesia treatment. Meanwhile, the respiration and oxygen saturation in the EA group were significantly improved compared with that of the IA group (p < .05). The VAS in the EA group was significantly lower than that in the IA group (p < .05), and the Karnofsky score in the EA group was significantly higher than that in the IA group (p < .05). Moreover, patients treated with EA felt more satisfied and experienced fewer complications than those with IA (p < .05). The epidural self-controlled analgesia may greatly improve the quality of life and relieve the pain in patients with advanced cancer.

E-cadherin expression and prognosis of oral cancer: a meta-analysis.

This study aims to evaluate the association of E-cadherin expression with the prognosis of oral squamous cell carcinoma (OSCC). Literature retrieval, selection and assessment, data extraction, and meta-analyses were performed according to the Revman 5.0 guidelines. In the meta-analysis, we utilized either fixed effects or random effects model to pool the HR according to the test of heterogeneity. A total of nine eligible studies included 973 OSCC patients were analyzed. Of the patients, 76.3 % had low expression of E-cadherin according to the cutoff value defined by the authors. The pooled hazard ratio (HR) of low expression of E-cadherin for overall survival (OS) was 0.65 (95 % CI 0.52 to 0.80, P<0.001); in Asian population, the HR for overall survival of the patients with reduced expression of E-cadherin was 0.84 (95 % CI 0.75 to 0.95, P=0.006), and in non-Asian population, the HR for overall survival of the patients with reduced expression of E-cadherin was 0.54 (95 % CI 0.41 to 0.69, P<0.001). Patients with reduced expression of E-cadherin appear to have a poorer OS compared with those with normal or higher expression of E-cadherin.

Kin17 regulates proper cortical localization of Miranda in Drosophila neuroblasts by regulating Flfl expression.

During asymmetric division of Drosophila larval neuroblasts, the fate determinant Prospero (Pros) and its adaptor Miranda (Mira) are segregated to the basal cortex through atypical protein kinase C (aPKC) phosphorylation of Mira and displacement from the apical cortex, but Mira localization after aPKC phosphorylation is not well understood. We identify Kin17, a DNA replication and repair protein, as a regulator of Mira localization during asymmetric cell division. Loss of Kin17 leads to aberrant localization of Mira and Pros to the centrosome, cytoplasm, and nucleus. We provide evidence to show that the mislocalization of Mira and Pros is likely due to reduced expression of Falafel (Flfl), a component of protein phosphatase 4 (PP4), and defects in dephosphorylation of serine-96 of Mira. Our work reveals that Mira is likely dephosphorylated by PP4 at the centrosome to ensure proper basal localization of Mira after aPKC phosphorylation and that Kin17 regulates PP4 activity by regulating Flfl expression.

Vitamin B6 and folate intake are associated with lower risk of severe headache or migraine in adults: An analysis based on NHANES 1999-2004.

Previous studies have shown that B vitamins can relieve migraine. However, the association between vitamin B6 and folate, 2 important B vitamins consumed in the diet, with migraine have received minimal attention. This study explored the independent relationships between dietary vitamin B6 and folate intake with migraine and the interaction effect of these 2 nutrients on migraine in US adults. We hypothesized that vitamin B6 and folate intake would be inversely associated with migraine. This study included cross-sectional data from participants aged 20 years and older who participated in the National Health and Nutrition Examination Survey from 1999 to 2004. We conducted multivariate logistic regression and restricted cubic spline regression to explore the association between dietary vitamin B6 and folate intake on migraine. Also, relative excess risk due to interaction, attributable proportion of interaction, and synergy index were used to assess additive interactions. A total of 7017 participants were included in this study, 1350 of whom were migraineurs. We determined that vitamin B6 and folate intake revealed a negative association with severe headache or migraine (0.66; 95% confidence interval [CI], 0.47-0.89; P = .01 and 0.57; 95% CI, 0.42-0.78; P = .002]), respectively. Also, a significant interaction effect between a high mass of vitamin B6 and folate intake was observed for a lower risk of migraine (relative excess risk due to interaction, 0.28 [95% CI, 0.05-0.51]; attributable proportion of interaction: 0.45 [95% CI, 0.05-0.86]; synergy index: 0.58 [95% CI, 0.40-0.83]). A high mass of vitamin B6 and folate intake (vitamin B6 intake ≥ 2.39 mg/day and folate intake ≥ 502.01 µg/day) presented a synergistic interaction with migraine, suggesting that these 2 nutrients might be beneficial in preventing migraine.

Luteolin inhibits angiogenesis and enhances radiotherapy sensitivity of laryngeal cancer via downregulating Integrin ß1.

AIM: To demonstrate the role and mechanism of luteolin in radio-sensitization and angiogenesis of laryngeal cancer. METHODS: Firstly, we analyzed the cytotoxicity of Luteolin and radiation sensitive cytotoxicity through CCK8, and selected subsequent radiation doses and Luteolin concentrations. Next, we further analyzed the effects of Luteolin on radiation sensitivity and neovascularization of laryngeal cancer, and conducted CCK8, plate cloning, and angiogenesis experiments, respectively. At the same time, the effects of individual treatment and combination treatment on the expression of Integrin ß1 and VEGFA were analyzed through immunofluorescence analysis. We also analyzed the regulation of Integrin ß1 protein expression by Luteolin through Western blot. To investigate the mechanism of Integrin ß1, we transfected overexpressed and silenced Integrin ß1 vectors and analyzed the role of Integrin ß1 in Luteolin enhancing radiation sensitivity of laryngeal cancer by repeating the above experiments. We have also constructed an in vivo subcutaneous tumor transplantation model to further validate the cell experimental results. The expression of Integrin, KI67, VEGFA, and CD31 was analyzed through Western blot and immunohistochemistry experiments. RESULTS: Radiation inhibited cell proliferation and decreased Integrin ß1 expression, and increased the radiosensitivity through inhibiting cell proliferation, and inhibit angiogenesis during radiation. Overexpression of Integrin ß1 weakened radiotherapy sensitivity on the basis of cells treated with combined administration. Integrin ß1 is considered as the downstream molecule of luteolin, participating in radiosensitivity of luteolin to FaDu cells. Animal experiments also demonstrated that luteolin strengthened tumor suppression and anti-angiogenesis during radiation via Integrin ß1. CONCLUSION: In summary, our results manifested that radio-sensitivity effect of luteolin depended on downregulating Integrin ß1 in laryngocarcinoma.

Effect of botulinum toxin type A on non-motor symptoms and quality of life in Meige syndrome.

Background: It has been shown in previous studies that botulinum toxin type A (BTX-A) can effectively relieve the motor symptoms of Meige syndrome. However, its effect on non-motor symptoms (NMS) and quality of life (QoL) has not been comprehensively studied. This study aimed to explore the effects of BTX-A on NMS and QoL and to clarify the relationship between changes in motor symptoms, NMS, and QoL after BTX-A. Methods: Seventy-five patients were recruited for the study. All patients were assessed by a series of clinical assessments before, one, and 3 months after BTX-A treatment. Dystonic symptoms, psychiatric disturbances, sleep disorders, and QoL were evaluated. Results: After 1 and 3 months of BTX-A treatment, the scores of motor symptoms, anxiety, and depression were significantly decreased (P < 0.05). Except for general health, the scores of the other 36-item short-form health survey QoL subitems were significantly improved after BTX-A (P < 0.05). After 1 month of treatment, the changes in anxiety and depression were not correlated with changes in motor symptoms (P > 0.05). Still, they were negatively correlated with changes in physical functioning, role-physical and mental component summary QoL (P < 0.05). Conclusions: BTX-A effectively improved motor symptoms, anxiety, depression, and QoL. Anxiety and depression improvement did not correlate with motor symptom changes after BTX-A, and QoL improvements were strongly associated with psychiatric disturbances.

Association between first 24-h mean body temperature and mortality in patients with diastolic heart failure in intensive care unit: A retrospective cohort study.

Background: Body temperature (BT) has been used to evaluate the outcomes of patients with various diseases. In this study, patients with diastolic heart failure (DHF) in the intensive care unit (ICU) were examined for a correlation between BT and mortality. Methods: This was a retrospective cohort study of the Medical Information Mart for Intensive Care (MIMIC)-IV dataset. A total of 4,153 patients with DHF were included. The primary outcomes were 28-day ICU and higher in-hospital mortality rates. BT was used in the analyses both as a continuous variable and as a categorical variable. According to the distribution of BT, the patients were categorized into three groups (hypothermia BT <36.5°C, normal 36.5°C ≤ BT <37.5°C, and hyperthermia BT ≥37.5°C). Multivariate logistic regression analysis was performed to explore the association between BT and patient outcomes. Results: The proportions of the groups were 23.6, 69.2, and 7.2%, respectively. As a continuous variable, every 1°C increase in BT was associated with a 21% decrease in 28-day ICU mortality (OR: 0.79, 95% CI: 0.66-0.96, and p = 0.019) and a 23% decrease in in-hospital mortality (OR: 0.77, 95% CI: 0.66-0.91; and p = 0.002). When BT was used as a categorical variable, hypothermia was significantly associated with both 28-day ICU mortality (OR: 1.3, 95% CI: 1.03-1.65; and p = 0.026) and in-hospital mortality (OR: 1.31, 95% CI: 1.07-1.59; and p = 0.008). No statistical differences were observed between 28-day ICU mortality and in-hospital mortality with hyperthermia after adjustment. Conclusion: The first 24-h mean BT after ICU admission was associated with 28-day ICU and in-hospital mortality in patients with DHF. Hypothermia significantly increased mortality, whereas hyperthermia did not.

Downregulation of Sp1 Inhibits the Expression of HDAC1/SOX10 to Alleviate Neuropathic Pain-like Behaviors after Spinal Nerve Ligation in Mice.

Specific protein 1 (Sp1) is a member of the Sp/Kruppel-like factor family, which regulates cellular processes of neurons in the nervous system. This study was performed to examine the regulatory role and the underlying mechanism of transcription factor Sp1 in neuropathic pain (NP)-like behaviors after spinal nerve ligation (SNL). Sp1 and histone deacetylase 1(HDAC1) expressions were determined in the C57BL6 mouse model with NP-like behaviors after SNL, which demonstrated that Sp1 and HDAC1 elevation occurred in neurons in the spinal dorsal horn of SNL mice. The chromatin immunoprecipitation assay verified that Sp1 was bound to the HDAC1 promoter region and HDAC1 to the SRY-box-containing gene 10 (SOX10) promoter region in the spinal dorsal horn. Immunofluorescence was performed to determine Sp1, HDAC1, and SOX10 in the spinal dorsal horn neurons as well as the neuronal marker (NeuN), microglial marker (Iba-1), and astrocyte marker (GFAP). The nociceptive test was performed to characterize the hindlimb paw withdrawal threshold (PWT) and paw withdrawal latency (PWL) of mice 0-10 days after model establishment. Loss- and gain-of-function assays revealed that Sp1 promoted HDAC1 expression, and HDAC1 in turn promoted SOX10 expression. HDAC1 elevation reversed the effects of Sp1 silencing, and the increased PWT and PWL of SNL mice were negated after SOX10 overexpression. Meanwhile, SOX10 also restored the results by Sp1 knockdown. Collectively, downregulating Sp1 alleviates NP-like behaviors after SNL via the HDAC1/SOX10 axis.

Comparative antimicrobial activity and mechanism of action of bovine lactoferricin-derived synthetic peptides.

Lactoferricin B (LfcinB), a 25 residue peptide derived from the N-terminal of bovine lactoferrin (bLF), causes depolarization of the cytoplasmic membrane in susceptible bacteria. Its mechanism of action, however, still needs to be elucidated. In the present study, synthetic LfcinB (without a disulfide bridge) and LfcinB (C-C; with a disulfide bridge) as well as three derivatives with 15-, 11- and 9-residue peptides were prepared to investigate their antimicrobial nature and mechanisms. The antimicrobial properties were measured via minimum inhibitory concentration (MIC) determinations, killing kinetics assays and synergy testing, and hemolytic activities were assessed by hemoglobin release. Finally, the morphology of peptide-treated bacteria was determined by atomic force microscopy (AFM). We found that there was no difference in MICs between LfcinB and LfcinB (C-C). Among the derivatives, only LfcinB15 maintained nearly the same level as LfcinB, in the MIC range of 16-128 µg/ml, and the MICs of LfcinB11 (64-256 µg/ml) were 4 times more than LfcinB, while LfcinB9 exhibited the lowest antimicrobial activity. When treated at MIC for 1 h, many blebs were formed and holes of various sizes appeared on the cell surface, but the cell still maintained its integrity. This suggested that LfcinB had a major permeability effect on the cytoplasmic membrane of both Gram-positive and Gram-negative bacteria, which also indicated it may be a possible intracellular target. Among the tested antibiotics, aureomycin increased the bactericidal activity of LfcinB against E. coli, S. aureus and P. aeruginosa, but neomycin did not have such an effect. We also found that the combination of cecropin A and LfcinB had synergistic effects against E. coli.

Automation of binaural headphone audio calibration on an artificial head.

In studies with auralisation of audio stimuli over headphones, accurate presentation of headphone audio is critical for replicability and ecological validity. Audio stimuli levels are usually calibrated by placing studio quality headphones on an artificial head and torso simulator. Manual adjustment of audio tracks becomes laborious when the number of stimuli is large, especially for applications with large datasets. To increase reliability and productivity, we devised a stimulus-agnostic, automated calibration procedure for headphone audio via an artificial head and torso simulator, with a LabVIEW implementation available at doi:10.21979/N9/0KYIAU.•The procedure uses a National Instruments NI-9234 data acquisition module and works with any ITU­T P.58:2013 and ANSI/ASA S 3.36:2012 compliant artificial head measurement systems.•The procedure works by an adjustment to a generic guess, followed by a modified binary search, wherein the audio stimuli are calibrated to within a user-specified tolerance level.•Each stimulus in a validation run to calibrate 250 stimuli to 65.0 ± 0.5 dB was played back an average of 2.22 ± 0.92 times before successful calibration, thus demonstrating the robustness and efficiency of our proposed method.

Imbibition and Oil Recovery Mechanism of Fracturing Fluids in Tight Sandstone Reservoirs.

The fracturing fluid residing in a reservoir undergoes spontaneous imbibition. Here, to explore the mechanism of fracturing fluid imbibition and oil displacement, experiments on the spontaneous imbibition of fracturing fluid under different influencing factors were conducted on a core sample from the Ordos Basin of the Chang 8 formation. Combined with nuclear magnetic resonance technology, we quantitatively evaluated the degree of oil production of different pores during the fracturing fluid displacement process. Experimental results show that fracturing fluid salinity, fracturing fluid interfacial tension, and crude oil viscosity are negatively correlated with oil recovery. The phenomenon of microscale imbibition oil displacement occurs in pores of various scales in the core. The imbibition scale was between 0.10 and 1608.23 ms. The degree of crude oil production in the pores at each scale increased with increasing imbibition time. Moreover, the crude oil viscosity, fracturing fluid salinity, and fracturing fluid interfacial tension are negatively correlated with the degree of oil production at various pore scales. Decreasing crude oil viscosity significantly improves the degree of small-pore (0.1-16.68 ms) crude oil production; the low interfacial tension possesses a higher degree of oil production in the large pores (>16.68 ms), and the increment in the degree of oil production under different salinities of the small pores (0.1-16.68 ms) is greater than that of the large pores (>16.68 ms).

Lipoxin A4 Inhibits NLRP3 Inflammasome Activation in Rats With Non-compressive Disc Herniation Through the JNK1/Beclin-1/PI3KC3 Pathway.

BACKGROUND: Non-compressive disc herniation is induced by an inflammatory response from the nucleus pulposus tissue and nerve roots. Lipoxins (LXs) are important endogenous anti-inflammatory mediators in the body, helping to inhibit neutrophil recruitment and stimulate autophagy in monocytes and macrophages. Here, we investigated the molecular mechanisms underlying the effects of exogenous lipoxin administration on rats with non-compressive disc herniation. METHOD: A non-compressive disc herniation model was established in rats. Fifty rats were randomly divided into: sham group, model group, PI3K inhibitor (LY294002) group, lipoxin A4 group (LXA4), and PI3K inhibitor and lipoxin A4 group (LY294002 + LXA4). Similar groupings were established for rat spinal neurons. Changes in the mechanical pain threshold and thermal pain threshold were monitored at different times. The expression of proinflammatory and anti-inflammatory mediators was assessed by ELISA, while immunohistochemistry was employed to measure the expression levels of NLRP3 and p-JNK1. The expression levels of autophagy-related proteins were measured by western blot. RESULTS: In vivo, the pain threshold was markedly decreased in the model group at each time point examined compared with that in sham group. LY294002 treatment further reduced the pain threshold. After LXA4 injection, the pain threshold was significantly increased, and the effect of LY294002 was significantly weakened (p < 0.05). The levels of proinflammatory cytokines were increased in rats with non-compressive disc herniation, and these levels were further increased by LY294002 treatment (p < 0.05). However, treatment with LXA4 significantly reduced the levels of these proinflammatory cytokines in the model group (p < 0.05). The opposite effect was observed for anti-inflammatory mediators. The expression of NLRP3 was largely increased in the model group compared with that in the sham group (p < 0.05). Treatment with LY294002 also increased the NLRP3 expression level, while the administration of LXA4 elicited the opposite effect. Furthermore, western blot analysis showed that the expression of autophagy-related proteins was greatly decreased in the model group, whereas it was significantly increased in the LXA4 group (p < 0.05). The in vitro results were consistent with the outcomes observed in vivo. CONCLUSIONS: These data suggested that LXA4 inhibited NLRP3 activation in rats with non-compressive disc herniation by regulating the JNK1/beclin-1/PI3KC3 pathway.

Corrigendum: Lipoxin A4 Inhibits NLRP3 Inflammasome Activation in Rats With Non-compressive Disc Herniation Through the JNK1/Beclin-1/PI3KC3 Pathway.

[This corrects the article DOI: 10.3389/fnins.2020.00799.].

Recombinant expression of porcine lactoferrin peptide LF-6 with intein technology and its immunomodulatory function in ETEC K88-infected mice.

LF-6 is a modified antibacterial peptide derived from LFP-20, a major active ingredient of porcine lactoferrin, whose antibacterial activity is 200 times higher than its native protein counterpart. Moreover, LF-6 displays even higher antibacterial activity than LFP-20 and negligible toxic adverse effects, make it a potential therapeutic agent for antibacterial purposes. Escherichia coli expression system has been a preferred choice and workhorse for most recombinant proteins. However, LF-6 must be coexpressed with a fusion partner to avoid its potentially fatal toxicity which would threat E. coli expression system. In this study, we successfully introduced intein system to solve this problem, which LF-6 was N-terminally fused to dithiothreitol (DTT)-induced self-cleavable intein, and it conduct cleavage when the intein-fusion peptide passing through a chromatography column filled with chitin, then the spliced peptide was purified with RP-HPLC and identified with mass spectroscopy. A bacteriostatic test showed that the recombinant LF-6 displayed nearly the same antibacterial activity as the chemically synthetized LF-6, and an in vivo immunoprotection analysis showed that the recombinant LF-6 exerted protective effects on Escherichia coli (ETEC)-K88-infected mice, which significantly reduced the pro-inflammatory cytokines level in plasma and intestine, and resistant to intestinal mucosal injury compared to the infective alone groups. Our study indicates that the intein system allows a safe and efficient method to produce recombinant LF-6, which not only has antibacterial activity, but more importantly, has an immunomodulatory function.