A novel therapeutic approach to modulate the inflammatory cascade: A timely exogenous local inflammatory response attenuates the sepsis-induced cytokine storm.

BACKGROUND: The emergence of severe sepsis is contingent upon the occurrence of a cytokine storm (CS), a multifaceted process intricately entwined with the temporal dimension, thereby rendering the infection response remarkably intricate. Consequently, it becomes imperative to discern and accurately identify the optimal timing for interventions, predicated upon the dynamic timeline of inflammatory changes. Moreover, the administration of exogenous low-dose pro-inflammatory agents has exhibited the potential to impede the relentless progression of the inflammatory cascade. Hence, the present study aims to scrutinize the impact of exogenous Local Inflammatory Response (eLIR) on the body surface in the context of the inflammatory cascade during sepsis, within a temporal framework, with a particular emphasis on the point of exacerbation of inflammation. METHODS: Rats were induced sterile sepsis by intraperitoneal injection of zymosan (ZY) at an appropriate dosage. The temporal progression of inflammatory changes and eLIR effects were described based on the trend of serum crucial inflammatory cytokines, tring to quest time-point of inflammatory aggravation in sepsis. Then, the varying degrees of surface inflammation caused by eLIR on this time point leading to the final effects on the inflammatory cascade response were explored. In addition, given the authentic pathological progression of sepsis, further observation was conducted on the impact of another intervention timing of eLIR on the inflammatory cascade. The survival rate was measured. Serum and organ related inflammatory cytokines were detected, and organ histopathology was investigated. RESULTS: In present study, a dosage of 600 mg/kg ZY was found to be optimal for the sterile sepsis model. Initiating eLIR 6 h prior to ZY injection, the maximum effect point of eLIR could be precisely align with the inflammatory aggravation point of sterile sepsis. Initiating eLIR at this time, 3 sessions of eLIR were found to be more effective than 1 or 2 sessions in mitigating inflammatory responses during the initial stage of inflammation and the peak of inflammation. Notably, the findings also suggested that this intervention improve survival rate. In addition, the anti-inflammatory efficacy has been substantially diminished by the prompt initiation of 3 sessions of eLIR immediately after ZY injection at the onset of sepsis. Similarly, the current findings did not demonstrate a statistically significant enhancement in survival rates with eLIR at this time point. CONCLUSIONS: Compared with the initial stage of inflammation, low-scale inflammation caused by a certain intensity of eLIR (3 sessions) on the body surface can more effectively pry the inflammation aggravation time-point, thereby shifting the pro-inflammatory to anti-inflammatory milieu, impeding the disproportionate cytokines release in inflammatory diseases, slowing down the inflammatory cascade, and improving the survival rate of sepsis.

Risk Factors and Drug Efficacy for Severe Illness in Hemodialysis Patients Infected with the Omicron Variant of COVID-19.

INTRODUCTION: The Omicron variant of the novel coronavirus (COVID-19) has been spreading more rapidly and is more infectious, posing a higher risk of death and treatment difficulty for patients undergoing hemodialysis. This study aims to explore the severity rate and risk factors for hemodialysis patients infected with the Omicron variant and to conduct a preliminary analysis of the clinical efficacy of drugs. METHODS: Clinical and biochemical indicators of 219 hemodialysis patients infected with the Omicron variant were statistically analyzed. The patients were divided into two groups based on whether they were severely ill or not, and multiple regression analysis was conducted to determine the risk factors for severe illness. The severely ill patients were then grouped based on discharge or death, and the treatment drugs were included as influencing factors for multiple regression analysis to determine the risk factors and protective factors for death of severely ill patients, and drug efficacy analysis was conducted. RESULTS: Analysis showed that diabetes, low oxygen saturation, and high C-reactive protein (CRP) were independent risk factors for severe illness in hemodialysis patients infected with the Omicron variant. A history of diabetes and high C-reactive significantly increased the risk of severe illness in patients (aOR: 1.450; aOR: 1.011), while a high oxygen saturation level can reduce this risk (aOR: 0.871). In addition, respiratory distress was an independent risk factor for death in severely patients, significantly reducing the probability of discharge for patients (aOR: 0.152). The drugs thymalfasin and Tanreqing significantly increased the probability of discharge for patients (aOR: 1.472; aOR: 3.104), with the latter having a higher correlation, but with a relatively longer effective course. CONCLUSION: Hemodialysis patients infected with the Omicron variant of COVID-19 should pay special attention to their history of diabetes, CRP, and oxygen saturation levels, as well as respiratory distress symptoms, to reduce the risk of severe illness and death. In addition, thymalfasin and Tanreqing may be considered in treatment.

Hydrogenase and Nitrogenase: Key Catalysts in Biohydrogen Production.

Hydrogen with high energy content is considered to be a promising alternative clean energy source. Biohydrogen production through microbes provides a renewable and immense hydrogen supply by utilizing raw materials such as inexhaustible natural sunlight, water, and even organic waste, which is supposed to solve the two problems of "energy supply and environment protection" at the same time. Hydrogenases and nitrogenases are two classes of key enzymes involved in biohydrogen production and can be applied under different biological conditions. Both the research on enzymatic catalytic mechanisms and the innovations of enzymatic techniques are important and necessary for the application of biohydrogen production. In this review, we introduce the enzymatic structures related to biohydrogen production, summarize recent enzymatic and genetic engineering works to enhance hydrogen production, and describe the chemical efforts of novel synthetic artificial enzymes inspired by the two biocatalysts. Continual studies on the two types of enzymes in the future will further improve the efficiency of biohydrogen production and contribute to the economic feasibility of biohydrogen as an energy source.

Artificial Small Molecules as Cofactors and Biomacromolecular Building Blocks in Synthetic Biology: Design, Synthesis, Applications, and Challenges.

Enzymes are essential catalysts for various chemical reactions in biological systems and often rely on metal ions or cofactors to stabilize their structure or perform functions. Improving enzyme performance has always been an important direction of protein engineering. In recent years, various artificial small molecules have been successfully used in enzyme engineering. The types of enzymatic reactions and metabolic pathways in cells can be expanded by the incorporation of these artificial small molecules either as cofactors or as building blocks of proteins and nucleic acids, which greatly promotes the development and application of biotechnology. In this review, we summarized research on artificial small molecules including biological metal cluster mimics, coenzyme analogs (mNADs), designer cofactors, non-natural nucleotides (XNAs), and non-natural amino acids (nnAAs), focusing on their design, synthesis, and applications as well as the current challenges in synthetic biology.

Ferroptosis is partially responsible for dexamethasone-induced T cell ablation, but not osteoporosis in larval zebrafish.

Glucocorticoids (GCs) have been widely detected in the aquatic system. However, the hazardous effects of GCs on aquatic organisms were underestimated, and the mechanisms of GCs-induced toxic effects in fish were largely unknown. The zebrafish larvae at 3 dpf were exposed to dexamethasone (DEX) for 48 h, and the toxic effects and the underlying mechanisms were investigated in the current study. The T cells were ablated in zebrafish larvae after being treated with 1, 3, 10, 30 and 100 µM of DEX for 48 h. In addition, osteoporosis was induced and the regeneration of the caudal fin was inhibited, by 48 h-exposure to 10, 30 and 100 µM of DEX. The transcriptomic analysis, biochemical parameters and gene expression profiles revealed that ferroptosis possibly contributed to the DEX-induced toxic effects in zebrafish larvae. Finally, Fer-1 treatment partially attenuated the DEX-induced T cell ablation, but not osteoporosis in zebrafish larvae. Taken together, the current study proved the toxic effects of DEX on zebrafish larvae, and elucidated that ferroptosis was involved in DEX-induced toxicity, providing strong evidence for the toxic effects of GCs on aquatic organisms.

[Efficacy Evaluation of Three Endoscopic Therapies of Isolated Gastric Varices with Modified Tissue Adhesive].

Objective: To evaluate the efficacy of three endoscopic therapies of isolated gastric varices (IGV) with modified tissue adhesive. Methods: A retrospective analysis was conducted with the clinical data of 73 IGV patients who were treated between January 2008 and December 2019 at Beijing Ditan Hospital. Patient clinical data on age, sex, etiology, biochemistry findings, Child-Pugh classification, the type of spontaneous shunt, preoperative bleeding history, and the presence or absence of liver cancer were collected. The three therapies evaluated were endoscopic intravenous injection of tissue glue combined with lauromacrogol, endoscopic clip-assisted intravenous injection of tissue glue combined with lauromacrogol, and endoscopic clip and LOOP-assisted intravenous injection of tissue glue combined with lauromacrogol. Their respective clinical treatment outcomes, including ectopic embolism rate, survival rate, rebleeding rate, amount of lauromacrogol and tissue glue used, the number of endoscopic clips used, and the number of times of the procedure the patient underwent, were evaluated. Results: In the patient baseline data, Child-Pugh grade, preoperative thrombus formation, and the presence or absence of liver cancer, showed significant difference between the three therapies ( P<0.05). There was no significant difference in the rates of ectopic embolism among the three methods ( P>0.05), but no ectopic embolism occurred after endoscopic clip-assisted intravenous injection of tissue glue combined with lauromacrogol, or after endoscopic clip and LOOP-assisted intravenous injection of tissue glue combined with lauromacrogol. There was no significant difference in the survival rate, the rebleeding rate, amount of lauromacrogol and tissue glue used for the three therapies, but there was significant difference in the number of endoscopic clips used and the number of times the procedure was conducted within one year ( P<0.05). Conclusion: The two endoscopic therapies of intravenous injection of modified tissue glue, one assisted by clip and the other assisted by clip and LOOP, can help reduce the number of procedures IGV patients undergo within one year.

The smart growth of self-assembled silver nanoloops.

Enclosed silver nanoloops have unique features in manipulating and controlling light. However, even the conception of their growth mechanism has not been established. The intermediate structure at the growth stage were revealed as the crucial issue for studying their smart growth mechanism of silver nanoloops and nanowires. Early growth stage showed that silver nanorods and nanoparticles were grown in their respective polyvinylpyrrolidone micelles. Then, the silver nanorods and nanoparticles were assembled in a rod-particle-rod pattern via micelle-micelle coupling, forming linear silver nanowires. These silver nanowires were attracted by Van der Waals forces forming the initial nanoloop. Notably, there was a silver nanoparticle between the ends of two adjacent nanowires. This silver nanoparticle acted like solder and played a crucial role in connecting the two adjacent nanowires; consequently, a silver nanoloop was formed. This finding also suggested that similar smart growth patterns might exist for other one-dimensional and looped nanomaterials.

FAM172A Deletion May Enhance Hepatic Steatosis by Promoting ER Stress.

BACKGROUND: Endoplasmic reticulum (ER) stress is one of the major causes to the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Our previous study showed that maintains the homeostasis of ER could effectively alleviate NAFLD. In this study, we found that the loss of FAM172A increased ER stress. AIMS: The aims of this study were to explore whether FAM172A could improve NAFLD by inhibiting ER stress. METHODS: The expression levels of FAM172A and ER stress were detected by western blot. The method of immunofluorescence was used to determine FAM172A location. The interacted proteins of FAM172A were identified by immunocoprecipitation. The methods of MTS and caspase-3/7 activity were taken to confirm the effect of FAM172A on cell viability and proliferation. The expression levels of inflammation were detected by qPCR. RESULTS: We confirmed that FAM172A might alleviate NAFLD through inhibiting ER stress. Loss of FAM172A increased the expressions of ATF6, peIF2α, but decreased the expression of IRE1α. Then, it was shown that FAM172A located in ER and FAM172A directly interacted with ATF6 and peIF2α and IRE1α. More importantly, the binding of FAM172A and eIF2a in tunicamycin-treated group increased significantly compared with the control group. However, the binding of FAM172A and ATF6 or IRE1α did not change. Next, we found that the lack of FAM172A could produce more apoptosis and inflammation. CONCLUSIONS: Our results suggest that FAM172A improve steatosis by alleviating ER stress.

Prognosis of endotherapy versus splenectomy and devascularization for variceal bleeding in patients with hepatitis B-related cirrhosis.

OBJECTIVE: This study aimed to compare the long-term outcome of endotherapy versus a combination of splenectomy and devascularization for variceal bleeding in patients with hepatitis B-related cirrhosis (HBRC). MATERIALS AND METHODS: A total of 1074 patients with HBRC and acute variceal bleeding (AVB) treated with endotherapy and 248 patients with HBRC treated with a combination of splenectomy and devascularization surgery were included in the analysis. After one-to-one propensity score matching, 151 paired patients were selected. The primary end-point was death. The secondary outcomes were 3-year survival, 5-year survival, and rebleeding. Complications were recorded. RESULTS: The median follow-up time was 1165 days in the endoscopic group and 1709 days in the surgical group. Before matching, the 1-year, 3-year, and 5-year survival rates were significantly lower in the endoscopic group than in the surgical group (91.1 vs 96.3%, P = 0.017; 79.6 vs 91.6%, P = 0.001; 65.2 vs 81.3%, P = 0.001). After matching, no significant differences were found between groups (94.5 vs 95.2%, P = 0.767; 87.0 vs 88.9%, P = 0.635; 77.9 vs 77.9%, P = 0.905). The rebleeding rate was lower in the surgical group than in the endoscopic group; the rebleeding-free survival rate was similar in the two groups. No patient died of complications. No statistically significant difference was observed in complications between groups. CONCLUSIONS: Both endotherapy and a combination of splenectomy and devascularization are good choices for patients with AVB. The rebleeding rate was lower after the surgical procedure, but the long-term prognosis was similar.

Fluorine enrichment of vegetables and soil around an abandoned aluminium plant and its risk to human health.

In the process of electrolytic aluminium production, a large amount of fluoride is deposited into the surrounding environment. The growth of crops within these areas creates a state of high stress in plants that can easily result in excessive fluorine enrichment in agricultural products, which in turn poses a health threat to humans via the food chain. However, it is not clear what the degree of influence is or how long the impacts of fluorides in soil and agricultural products last for. In this study, 122 vegetable species and 36 surface soil samples were collected within 10 km of an aluminium plant that had been abandoned for five years. The single factor index and the geological accumulation index methods were used to evaluate the degree of fluorine pollution in vegetables and soil within the study area. The hazard index and the hazard quotient were used to assess vegetable and soil health risks, respectively. The results showed that the fluorine content of 89.26% of agricultural products exceeded the Chinese Maximum Levels of Contaminants in Foods and was higher than in other regions, indicating that the emissions of fluoride from the aluminium plant still had a significant effect on fluorine accumulation in vegetables. The total fluorine (Ft) content in the surrounding surface soil (average value 1328.32 mg kg-1) was similar to the soil fluorine background in the nearby uncontaminated settlement area, but the soil water-soluble fluorine (Fw) was very high, indicating that the fluorine pollutants emitted from the aluminium plant had gradually been diluted by the high background of the original soil, but the solubility of these pollutants was higher (average 15.00 mg kg-1) and would continue to threaten the safety of agricultural products in this region. Within 1 km of the abandoned aluminium plant, the degree of fluorine enrichment in vegetables, and Ft and Fw in soil were significantly higher than other ranges, indicating that this was the main fluoride deposit area. Based on the HI and HQ evaluation, vegetables and ground dust around the aluminium plant still had high non-carcinogenic risks for children, even though it has been abandoned for more than five years.

LncRNA MEG3 expression in sepsis and its effect on LPS-induced macrophage function.

Sepsis is a dangerous disease that is caused by an overreaction of the body's immune system to infection and gradually spreads throughout the body. This experiment was carried out to explore the expression of LncRNA MEG3 in sepsis and its effect on LPS-induced macrophage function. Methods 60 sepsis patients admitted to our hospital from February 2017 to September 2018 were selected as the sepsis group, and 50 non-septic patients diagnosed and treated in our hospital during the same period were selected as the control group. qRT-PCR was used to detect the expression level of MEG3. ROC curve was used to analyze the diagnostic value of serum MEG3 in sepsis. The human macrophage cell line U937 was cultured in vitro and randomly divided into NC group, LPS group, LPS + pcDNA group, and LPS + pcDNA-MEG3 group. Flow cytometry was applied to detect the apoptosis rate. The levels of IL-1ß and TNF-α were detected by ELISA. Western blot was used to detect the expression of Bax, Bcl-2 and NF-κB signaling pathway-related proteins p65 and p-p65. Results: The expression level of serum MEG3 in the sepsis group was significantly lower than that in the control group (P <0.05). ROC curve analysis showed that the AUC area was 0.856, the sensitivity was 0.700, and the specificity was 0.883. Compared with the NC group, the macrophage apoptosis rate in the LPS group was increased (P <0.05), the levels of Bax and p-p65 protein were significantly increased (P <0.05), and the level of Bcl-2 protein was decreased (P <0.05), the levels of IL-1ß and TNF-α were increased (P <0.05). Compared with the LPS + pcDNA group, the apoptosis rate of the LPS + pcDNA-MEG3 group was significantly reduced (P <0.05), the levels of Bax and p-p65 protein were reduced (P <0.05), and the level of Bcl-2 protein was significantly increased (P <0.05), the levels of IL-1ß and TNF-α were reduced (P <0.05). Conclusion: The low expression of LncRNA MEG3 in the serum of patients with sepsis can predict the occurrence of sepsis. Overexpression of MEG3 can inhibit LPS-induced macrophage apoptosis and secretion of inflammatory factors by inhibiting the activation of the NF-κB signaling pathway.

Synthesis of two novel pyrazolo[1,5-a]pyrimidine compounds with antibacterial activity and biophysical insights into their interactions with plasma protein.

Two novel water-soluble pyrazolo[1,5-a]pyrimidine derivatives, 5-chloro-7-(4-methyl-piperazin -1-yl)-pyrazolo[1,5-a]pyrimidine (CMPS) and N'-(5-chloro-pyrazolo[1,5-a]pyrimidin-7-yl)-N,N-dimethyl -propane-1,3-diamine (NCPS), were synthesized and characterized with antibacterial activity. Then, the interactions of these compounds with bovine serum albumin (BSA) were studied by fluorescence, time-resolved fluorescence, circular dichroism (CD) spectroscopy and molecular docking. The results indicate that both CMPS and NCPS could effectively quench the intrinsic fluorescence of BSA via a static quenching process. The energy transfer from BSA to CMPS and NCPS may occur with high probability. Both CMPS and NCPS bind in the site I of BSA. The hydrophobic force and hydrogen bonds play major roles in the complex formation. Binding constants for both systems show that the affinity of CMPS binding to BSA is stronger than that of NCPS. The results of three-dimensional fluorescence and CD spectra reveal that the binding of CMPS and NCPS to BSA can induce conformational changes of BSA, and the influence of CMPS is slightly stronger than that of NCPS.

New model predicting gastroesophageal varices and variceal hemorrhage in patients with chronic liver disease.

INTRODUCTION AND OBJECTIVES: The predictors for gastroesophageal varices (GOV) and hemorrhage development have not been well studied in different liver diseases or different population. This study aimed to evaluate whether a new algorithm focusing on chronic hepatitis B (CHB) patients is also applicable to other chronic liver diseases (CLDs) in Chinese population. PATIENTS OR MATERIALS AND METHODS: We retrospectively analyzed 659 CHB patients and 386 patients with other CLDs. A total of 439 CHB patients were included in training set, the other 220 CHB patients and other patients with CLDs were included in validation set. A new algorithm for diagnosing GOV was established and its sensitivity and specificity for predicting the varices was verified. RESULTS: Multivariable logistic regression revealed that the rough surface of the liver (p<0.001), splenic thickness (p<0.001), and liver stiffness (p=0.006) were independent predictors of GOV. The new algorithm was considered to be a reliable diagnostic model to evaluate the presence of varices. The AUROC was 0.94 (p<0.001) in CHB validation set and 0.90 (<0.001) in non-CHB validation set. When the cut-off value was chosen as -1.048, the sensitivity and specificity in diagnosing GOV in CHB population were 89.1% and 82.5%, respectively. Importantly, the new algorithm accurately predicted the variceal hemorrhage not only in CHB patients, but also in patients with other CLDs. CONCLUSION: The new algorithm is regarded as a reliable model to prognosticate varices and variceal hemorrhage, and stratified not only the high-risk CHB patients, but also in patients with other CLDs for developing GOV and variceal bleeding.

Antiviral therapy reduces rebleeding rate in patients with hepatitis B-related cirrhosis with acute variceal bleeding after endotherapy.

BACKGROUND: The preventive effects of antiviral therapy to reduce rebleeding rate in patients with hepatitis B-related cirrhosis undergoing endoscopic treatment have not yet been reported. METHODS: In this retrospective cohort study, 1139 patients with chronic hepatitis B with first acute variceal bleeding after endoscopic therapy from September 2008 to December 2017 were included. Among them, 923 who received and 216 who did not receive antiviral therapy were followed up for rebleeding. Cumulative rebleeding rate was calculated using the Kaplan-Meier method. Univariate and multivariate logistic regression analyses were performed to estimate the effects of antiviral therapy on rebleeding risk. The propensity score matched method and inverse probability of treatment weighting analysis were used to calculate the rebleeding rate between the antiviral and non-antiviral groups. RESULTS: The rebleeding rates were 40.5, 60.7, 72.6, and 89.2% in antiviral group at 1, 2, 3, and 5 years, respectively. The corresponding rebleeding rates in the non-antiviral group were 54.2, 72.4, 84.4, and 93.3%, respectively. The multivariate logistic regression analysis revealed that antiviral therapy was an independent protective factor associated with rebleeding. CONCLUSION: Antiviral treatment significantly reduced rebleeding rate in patients with HBV-related cirrhosis who received endoscopic treatment after the first variceal bleeding.

Association between bone mineral density and benign paroxysmal positional vertigo: a meta-analysis.

BACKGROUND: The association between bone mineral density (BMD) and benign paroxysmal positional vertigo (BPPV) has been investigated by multiple studies, but the conclusions are controversial. This meta-analysis was conducted to evaluate whether the bone mineral density is associated with BPPV. METHODS: The relevant studies were identified by searching PubMed, EMBASE, Cochrane Library, ScienceDirect, Web of Science database up to June 2018. Statas14.0 software was used for meta-analysis. We used the pooled odds ratio (OR) and 95% confidence interval (CI) to assess the incidence of osteoporosis and osteopenia in patients with BPPV and controls (free of BPPV disease). The standardized mean difference (SMD) and 95% confidence interval (CI) were used to assess the T score in BPPV patients and controls. This meta-analysis has been registered at International Prospective Register of Systematic Reviews (PROSPERO) (number CRD42018082271). RESULTS: A total of 11 studies were eligible for meta-analysis, including 1982 subjects. When compared with the controls, the total incidence of osteoporosis and osteopenia was significantly higher in BPPV patients (OR 3.27, 95% CI 2.66-4.03, p < 0.0001). Further analysis was conducted by separate discussion about the incidence of osteoporosis and osteopenia in BPPV patients, the result of which shows that both the incidence of osteoporosis (OR 3.48, 95% CI 1.86-6.51, p < 0.0001) and the incidence of osteopenia (OR 1.75, 95% CI 1.01-3.04, p < 0.0001) were higher in BPPV patients than that in controls. There was an significant reduction in T scores of BPPV patients (SMD - 0.82, 95% CI -1.18 to - 0.46, p < 0.0001). Publication bias for each analysis was evaluated by Egger's test and Begg's indicating that no publication bias existed. Sensitivity analysis was conducted for each analysis demonstrating that the results were robust. CONCLUSIONS: Our meta-analysis provided stronger evidence that patients with BPPV were associated with a lower T score and a higher risk of osteoporosis and osteopenia. The results demonstrated that lower bone mineral density may be a risk factor for BPPV. However, large-scare, multicenter clinical studies need to be carried out to explore the precise risk of osteoporosis and osteopenia in patients with BPPV in future.

Deletion of the C6orf120 gene with unknown function ameliorates autoimmune hepatitis induced by concanavalin A.

The present study was conducted to characterize the C6orf120 gene, by using C6orf120 gene-deleted rats (C6orf120-/-), to determine its role in the development and severity of autoimmune hepatitis induced by concanavalin A (Con A), as well as the underlying mechanisms. We found that following Con A injection, C6orf120-/- rats were less susceptible to developing autoimmune hepatitis with low levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) post challenge. Additionally, C6orf120 deficiency increased the frequency of cluster of differentiation (CD)4+ CD25+ Forkhead box P3+ regulatory T cells (Tregs) among intrahepatic lymphocytes, splenocytes, peripheral blood mononuclear cells, and CD4+ T in vitro. Moreover, C6orf120 deficiency downregulated interleukin (IL)-1ß, IL-6, tumor necrosis factor alpha-α, interferon-γ and IL-17a secretion in the plasma and liver tissues. Our results indicated that the C6orf120 gene-deleted rats were less susceptible to Con A-induced autoimmune hepatitis, which may be partly related to the increased frequency of Tregs and inhibited secretion of inflammatory cytokines.

Binding of fluphenazine with human serum albumin in the presence of rutin and quercetin: An evaluation of food-drug interaction by spectroscopic techniques.

The interactions between human serum albumin (HSA) and fluphenazine (FPZ) in the presence or absence of rutin or quercetin were studied by fluorescence, absorption and circular dichroism (CD) spectroscopy and molecular modeling. The results showed that the fluorescence quenching mechanism was static quenching by the formation of an HSA-FPZ complex. Entropy change (ΔS0 ) and enthalpy change (ΔH0 ) values were 68.42 J/(mol⋅K) and -4.637 kJ/mol, respectively, which indicated that hydrophobic interactions and hydrogen bonds played major roles in the acting forces. The interaction process was spontaneous because the Gibbs free energy change (ΔG0 ) values were negative. The results of competitive experiments demonstrated that FPZ was mainly located within HSA site I (sub-domain IIA). Molecular docking results were in agreement with the experimental conclusions of the thermodynamic parameters and competition experiments. Competitive binding to HSA between flavonoids and FPZ decreased the association constants and increased the binding distances of FPZ binding to HSA. The results of absorption, synchronous fluorescence, three-dimensional fluorescence, and CD spectra showed that the binding of FPZ to HSA caused conformational changes in HSA and simultaneous effects of FPZ and flavonoids induced further HSA conformational changes.

microRNA-126 targeting PIK3R2 promotes rheumatoid arthritis synovial fibro-blasts proliferation and resistance to apoptosis by regulating PI3K/AKT pathway.

OBJECTIVE: The purpose of our study was to elucidate the impact of microRNA-126 (miR-126) targeting PIK3R2 gene on cell proliferation and apoptosis of rheumatoid arthritis synovial fibro-blasts (RASFs) by regulating PI3K/AKT signal pathway. METHODS: The synovial tissue samples of this study were from 55 RA patients undergoing joint replacement and 27 healthy people undergoing joint repair due to trauma. The target genes of miR-126 were collected by the TargetScan and PIK3R2 as the direct target gene of miR-126 was confirmed by dual-luciferase reporter assay system. Our experiment had five groups including the blank control, miR-126 mimic, miR-126 mimic control, miR-126 inhibitor and miR-126 inhibitor control groups. Additionally, real-time quantitative polymerase chain reaction (RT-qPCR), Western-Blot, cell counting kit (CCK-8) and flow cytometry were carried out in this study. RESULTS: Compared with healthy individuals, the RA patients had increased miR-126, but decreased PIK3R2 mRNA expressions in the synovial tissues. Pearson correlation analysis indicated that miR-126 expression was negatively correlated with PIK3R2 mRNA expression (all P<0.05). When compared with the blank group respectively, the miR-126 mimic group had raising cell proportions in S and G2/M phases with reduced rate of cell apoptosis, while the miR-126 inhibitor group had raising cell proportions in G0/G1 and G2/M phases with increased rate of cell apoptosis (all P<0.05). Besides, compared with the blank control group, the miR-126 mimic group had declined expression of PIK3R2 protein with ascended expression of PI3K and p-AKT (all P<0.05), while the miR-126 inhibitor group had increased expression of PIK3R2 protein with decreased expression of PI3K and p-AKT (all P<0.05). CONCLUSION: Our study demonstrated that down-regulation of miR-126 may indirectly inhibit PI3K/AKT signaling pathway to disrupt the imbalance between growth and death of RASFs by targeting PIK3R2, which may be clinically helpful to find therapeutic strategies directed toward miR-126 function for RA patients.

Enhancement of the binding affinity of methylene blue to site I in human serum albumin by cupric and ferric ions.

In this work, the binding characteristics of methylene blue (MB) to human serum albumin (HSA) and the influence of Cu(2+) and Fe(3+) on the binding affinity of MB to HSA were investigated using fluorescence, absorption, circular dichroism (CD) spectroscopy and molecular modelling. The results of competitive binding experiments using the site probes ketoprofen and ibuprofen as specific markers suggested that MB was located in site I within sub-domain IIA of HSA. The molecular modelling results agreed with the results of competitive site marker experiments and the results of CD spectra indicated that the interaction between MB and HSA caused the conformational changes in HSA. The binding affinity of MB to HSA was enhanced but to a different extent in the presence of Cu(2+) and Fe(3+), respectively, which indicated that the influence of different metal ions varied. Enhancement of the binding affinity of MB to HSA in the presence of Cu(2+) is due to the formation of Cu(2+)-HSA complex leading to the conformational changes in HSA, whereas in the presence of Fe(3+), enhancement of the binding affinity is due to the greater stability of the Fe(3+)-HSA-MB complex compared with the MB-HSA complex.