Olmesartan medoxomil (OM) is one of the newest members of the angiotensin receptor blocker (ARB) family. The renoprotective effects of the angiotensin II type 1 receptor antagonist OM was investigated in a streptozotocin (STZ)-induced diabetic rat model. In this study, we investigated whether OM was able to ameliorate diabetic nephropathy (DN). Thirty male Sprague Dawley rats were assigned to 3 groups: the non-diabetic (group A, n=10), the untreated STZ-induced DN control (group B, n=10) and the STZ-induced DN treated with OM (group C, n=10). Blood pressure (BP) and glucose, creatinine (Cr), blood urea nitrogen (BUN), superoxide dismutase (SOD), malondialdehyde (MDA) microalbumin and urinary protein concentrations were measured. In STZ diabetic rats, BP, glucose, Cr, BUN, MDA and urinary protein levels were significantly increased compared to the non-diabetic control group. OM significantly improved the biological indices in the DN rats. The renal pathological changes were also observed under a light microscope. Our results suggested that OM exerted renoprotective effects on rats with STZ-induced diabetes.
renoprotective effects; olmesartan medoxomil; diabetic nephropathy
p-Aminosalicylic acid (PAS) is an important compound for treating multidrug-resistant tuberculosis (TB). Previous studies showed that thyA mutations are often related to PAS resistance in clinical isolates. We performed a systematic analysis of isolate genotypes and detected mutations in three folate pathway genes (folC, thyA, and ribD) in 61.1% (127/208) of PAS-resistant isolates, including 11 double mutants. This result expands our knowledge about the distribution and frequency of mutations related to PAS resistance in mycobacterial clinical isolates.
Background: Smoking is a major cause of morbidity and mortality. Smoking-related epigenetic biomarkers may open new avenues to better quantify the adverse health effects of smoking, and to better understanding of the underlying mechanisms. We aimed to evaluate the clinical implications of F2RL3 methylation, a novel epigenetic biomarker of smoking exposure disclosed by recent genome-wide methylation studies.
Methods: Blood DNA methylation at F2RL3 (also known as PAR-4) was quantified in baseline samples of 3588 participants aged 50–75 years in a large population-based prospective cohort study by MALDI-TOF mass spectrometry. Deaths were recorded during a median follow-up of 10.1 years. The associations of methylation intensity and of smoking with all-cause, cardiovascular, cancer and other mortality were assessed by Cox’s proportional hazards regression, controlling for potential confounding factors.
Results: Lower methylation intensity at F2RL3 was strongly associated with mortality. After adjustment for multiple covariates including smoking, hazard ratios [95% confidence interval (CI)] for death from any cause, cardiovascular disease, cancer or other causes were 2.60 (95% CI, 1.81-3.74), 2.45 (95% CI, 1.28-4.68), 2.94 (95% CI, 1.68-5.14) and 2.39 (95% CI, 1.11-5.16), respectively, in subjects in the lowest quartile of methylation intensity compared with subjects in the highest quartile. The associations with mortality outcomes were much stronger among men than among women. In addition, strong positive associations of smoking with each of the outcomes were substantially weakened, and almost disappeared when controlling for F2RL3 methylation intensity.
F2RL3 methylation is a strong predictor of mortality, including all-cause, cardiovascular, cancer and other mortality. Systemic adverse effects of smoking may be mediated by pathways associated with F2RL3 methylation.
F2RL3 methylation; PAR-4; smoking; mortality; prospective study
G protein-coupled estrogen receptor (GPER) has been shown to be important in several disease states such as estrogen sensitive cancers. While several selective ligands have been identified for the receptor, little is known about how they interact with GPER and how their structures influence their activity. Specifically, within one series of ligands, whose structure varied only at one position, the replacement of a hydrogen atom with an acetyl group changed a potent antagonist into a potent agonist. In this study, two GPER homology models were constructed based on the x-ray crystal structures of both the active and inactive β2-adrenergic receptors (β2AR) in an effort to characterize the differences of binding modes between agonists and antagonists to the receptor, and to understand their activity in relation to their structures. The knowledge attained in this study is expected to provide valuable information on GPER ligands structure activity relationship to benefit future rational design of potent agonists and antagonists of the receptor for potential therapeutic applications.
GPER; homology modeling; agonism; antagonism
We demonstrate theoretically and experimentally an interesting opaque state, which is based on an analog of electromagnetically induced transparency (EIT) in mechanism, in a metal hole array of the dimer lattice. By introducing a small difference to the dimer holes of each unit cell, the surface delocalized modes launching out from the dimer holes can have destructive interferences. Consequently, a narrow opaque window in the transparent background can be observed in the transmission spectrum. This surface-mode-induced opacity (SMIO) state is very sensitive to the difference of the dimer holes, which will promise various applications.
To study the serum Procalcitonin (PCT) level in inflammatory arthritis including gouty arthritis (GA), Rheumatoid arthritis (RA), and ankylosing spondylitis (AS) without any evidence of infection were evaluated the possible discriminative role of PCT in gouty arthritis susceptibility in southern Chinese Han Population.
Material and Methods
From Feb, 2012 to Feb, 2015, 51 patients with GA, 37 patients with RA, 41 patients with AS and 33 healthy control were enrolled in this study with no evidence of infections. The serum level of PCT (normal range < 0.05 ng/ml) was measured by electrochemiluminescence immunoassay (ECLIA). Disease activity was determined by scores of VAS (4.07 ± 1.15), DAS28 (4.97 ± 1.12), and ASDAS (2.97 ± 0.81) in GA, RA and AS groups respectively. Other laboratory parameters such as, serum creatinine (CRE), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), uric acid (UA) and white blood cells (WBC) were extracted from medical record system.
Serum PCT level was predominantly higher in gouty arthritis than in RA and AS patients, especially in the GA patients with tophi. PCT was significantly positively correlated with VAS, CRP and ESR in gouty arthritis and CRP in AS. PCT also had positive correlation-ship with ESR, DAS28 and ASDAS in RA and AS patients respectively, but significant differences were not observed.
These data suggested that PCT is not solely a biomarker for infection, but also an indicator in inflammatory arthritis, especially in gouty arthritis.
Few studies have examined the quality of life (QOL) in survivors of non-Hodgkin lymphoma (NHL). A total of 109 patients with NHL (58 aggressive [AGG], 51 indolent [IND]) completed two health-related QOL assessments using the Medical Outcomes Study 36-Item Short-Form Healthy Survey (MOS SF-36) and the Functional Assessment in Cancer Therapy – Fatigue (FACT-F). Scores between IND and AGG were compared using a two-sample t-test. Multiple linear regression was performed to account for any potentially explanatory variables. Overall, 70.6% had received chemotherapy and 55% had received immunotherapy. Some 17.6% of the IND group had received no therapy. The overall physical and mental component QOL scores of the SF-36 did not differ between survivors. Physical function in survivors of IND was significantly better when compared with that of AGG NHL. Our study reports a similar overall QOL between survivors of IND and AGG NHL. Physical function, however, may be more impaired in survivors of AGG NHL.
Quality of life; non-Hodgkin lymphoma; lymphoma; cancer survivorship
Dynamic systems based on consecutive thia-Michael and Henry reactions were generated and transformed using lipase-catalyzed asymmetric transformation. Substituted thiolane structures with three contiguous stereocenters were resolved in the process in high yields and high enantiomeric excesses.
adaptive features; biotransformations; chiral resolution; domino reactions; dynamic chemistry; enzymes; lipase; stereochemistry
A complex dynamic system based on a network of multiple reversible reactions has been established. The network was applied to a dynamic systemic resolution protocol based on kinetically controlled lipase-catalyzed transformations. This resulted in the formation of cyclized products, where two thiazolidinone compounds were efficiently produced from a range of potential transformations.
cyclization; dynamic chemistry; enzymes; lipases; resolution
Malignant gliomas are the most common malignant tumors in the central nervous system (CNS). Up to date, the prognosis of glioma is still very poor, effective therapy with less side-effect is very necessary. Herein, we identify a compound named as “331” selectively induced cell death in glioma cells but not in astrocytes. Compound 331 upregulated miR-494 and downregulated CDC20 in glioma cells but not in astrocytes. These results suggest that compound 331 could be a potential drug selectively targeting glioma cells through upregulating miR-494 and downregulating CDC20.
Serpins generally serve as inhibitors that utilize a mobile reactive center loop (RCL) as bait to trap protease targets. Here, we present the crystal structure of serpin18 from Bombyx mori at 1.65 Å resolution, which has a very short and stable RCL. Activity analysis showed that the inhibitory target of serpin18 is a cysteine protease rather than a serine protease. Notably, this inhibitiory reaction results from the formation of an intermediate complex, which then follows for the digestion of protease and inhibitor into small fragments. This activity differs from previously reported modes of inhibition for serpins. Our findings have thus provided novel structural insights into the unique inhibitory mechanism of serpin18. Furthermore, one physiological target of serpin18, fibroinase, was identified, which enables us to better define the potential role for serpin18 in regulating fibroinase activity during B. mori development.
Choroidal neovascularization (CNV) secondary to pathologic myopia has a very high incidence in global, especially in Asian, populations. It is a common cause of irreversible central vision loss, and severely affects the quality of life in the patients with pathologic myopia. The traditional therapeutic modalities for CNV secondary to pathologic myopia include thermal laser photocoagulation, surgical management, transpupillary thermotherapy, and photodynamic therapy with verteporfin. However, the long-term outcomes of these modalities are disappointing. Recently, intravitreal administration of anti-VEGF biological agents, including bevacizumab, ranibizumab, pegaptanib, aflibercept, and conbercept, has demonstrated promising outcomes for this ocular disease. The anti-VEGF regimens are more effective on improving visual acuity, reducing central fundus thickness and central retina thickness than the traditional modalities. These anti-VEGF agents thus hold the potential to become the first-line medicine for treatment of CNV secondary to pathologic myopia. This review follows the trend of “from bench to bedside”, initially discussing the pathogenesis of myopic CNV, delineating the molecular structures and mechanisms of action of the currently available anti-VEGF drugs, and then systematically comparing the up to date clinical applications as well as the efficacy and safety of the anti-VEGF drugs to the CNV secondary to pathologic myopia.
formation of new vessels; choroid membrane; pathologic myopia; vascular endothelial growth factor; molecular mechanisms; clinical trials
The 3-hydroxyisobutyrate dehydrogenase (HIBADH) is regarded as a human sperm-motility marker. However, the molecular mechanisms involved in the regulation of expression of the HIBADH gene in bulls remain largely unknown. HIBADH was detected in the testis, epididymis, and sperm via reverse transcription polymerase chain reaction and Western blot analysis. It is also expressed in the seminiferous epithelium, spermatids, and the entire epididymis, as detected by immunohistochemistry. Furthermore, HIBADH was expressed in the neck-piece and mid-piece of bull spermatids, as shown in the immunofluorescence assay. Using serially truncated bovine HIBADH promoters and luciferase constructs, we discovered an 878 bp (-703 bp to +175 bp) fragment that constitutes the core promoter region. One SNP g.-165 T>C of HIBADH was identified and genotyped in 307 Chinese Holstein bulls. Correlation analysis revealed that bulls with the TT genotype had higher initial sperm motility than those with the CC genotype (P < 0.05). Furthermore, the T- or C-containing loci (designated as pGL3-T and pGL3-C) were transiently transfected into MLTC-1 to test the effect of SNP on HIBADH expression. The luciferase reporter assay showed that the pGL3-T genotype exhibited 58% higher transcriptional activity than the pGL3-C genotype (P < 0.05). The bisulfite sequencing analysis revealed that the methylation pattern of the core promoter presented hypomethylation in the ejaculated semen in high-motility and low-motility bulls. The results demonstrated for the first time that the g.-165 T>C rather than methylation in the 5'-flanking region could affect the bovine sperm motility through the regulation of HIBADH gene transcriptional activity.
Huaier extract is attracting increased attention due to its biological activities, including antitumor, anti-parasite and immunomodulatory effects. Here, we investigated the role of autophagy in Huaier-induced cytotoxicity in MDA-MB-231, MDA-MB-468 and MCF7 breast cancer cells. Huaier treatment inhibited cell viability in all three cell lines and induced various large membranous vacuoles in the cytoplasm. In addition, electron microscopy, MDC staining, accumulated expression of autophagy markers and flow cytometry revealed that Huaier extract triggered autophagy. Inhibition of autophagy attenuated Huaier-induced cell death. Furthermore, Huaier extract inhibited the mammalian target of the rapamycin (mTOR)/S6K pathway in breast cancer cells. After implanting MDA-MB-231 cells subcutaneously into the right flank of BALB/c nu/nu mice, Huaier extract induced autophagy and effectively inhibited xenograft tumor growth. This study is the first to show that Huaier-induced cytotoxicity is partially mediated through autophagic cell death in breast cancer cells through suppression of the mTOR/S6K pathway.
To evaluate the association of the Hormad1 and Hormad2 single nucleotide polymorphisms (SNPs) variants with non-obstructive azoospermia (NOA) in the Chinese population.
In the present study, we assessed 10 single nucleotide polymorphisms (SNPs) of Hormad1 and Hormad2 using Sequenom iplex technology in 361 NOA cases and 368 normal controls from Chinese population.
We observed no statistical differences in the distribution of allele frequencies. Further genetic model analysis and haplotype analysis also showed no significant difference between the two groups. However, we found that genotype distribution of rs718772 of Hormad2 was significantly different between the larger testis group (average testis volume ≥10 ml) and the small testis group (average testis volume <10 ml) in the NOA patients (P = 0.035).
In conclusion, Hormad1 and Hormad2 might not be the susceptible genes for the non-obstructive azoospermia in our study population. However, rs718772 of Hormad2 variant might be associated with testis development in NOA patients.
Electronic supplementary material
The online version of this article (doi:10.1007/s10815-014-0244-x) contains supplementary material, which is available to authorized users.
Male infertility; Hormad1; Hormad2; Non-obstructive azoospermia (NOA)
syrup has nutraceutical potential given the macronutrients
(carbohydrates, primarily sucrose), micronutrients (minerals and vitamins),
and phytochemicals (primarily phenolics) found in this natural sweetener.
We conducted compositional (ash, fiber, carbohydrates, minerals, amino
acids, organic acids, vitamins, phytochemicals), in vitro biological,
and in vivo safety (animal toxicity) studies on maple syrup extracts
(MSX-1 and MSX-2) derived from two declassified maple syrup samples.
Along with macronutrient and micronutrient quantification, thirty-three
phytochemicals were identified (by HPLC-DAD), and nine phytochemicals,
including two new compounds, were isolated and identified (by NMR)
from MSX. At doses of up to 1000 mg/kg/day, MSX was well tolerated
with no signs of overt toxicity in rats. MSX showed antioxidant (2,2-diphenyl-1-picrylhydrazyl
(DPPH) assay) and anti-inflammatory (in RAW 264.7 macrophages) effects
and inhibited glucose consumption (by HepG2 cells) in vitro. Thus,
MSX should be further investigated for potential nutraceutical applications
given its similarity in chemical composition to pure maple syrup.
maple syrup; extract; nutraceutical; phytochemicals; biological; safety
Accurate estimation of the variability of heavy metals in river water and the hyporheic zone is crucial for pollution control and environmental management. The biotoxicities and potential ecological risks of heavy metals (Cu, Zn, Pb, Cd) in a solid-liquid two-phase system were estimated using the Geo-accumulation Index, Potential Ecological Risk Assessment and Quality Standard Index methods in the Weihe River of Shaanxi Province, China. Water and sediment samples were collected from five study sites during spring, summer and winter, 2013. The dominant species in the streambed sediments were chironomids and flutter earthworm, whose bioturbation mainly ranged from 0 to 20 cm. The concentrations of heavy metals in surface water and pore water varied obviously in spring and summer. The degrees of concentration of Cu and Cd in spring and summer were higher than the U.S. water quality Criteria Maximum Concentrations. Furthermore, the biotoxicities of Pb and Zn demonstrated season-spatial variations. The concentrations of Cu, Zn, Pb and Cd in spring and winter were significantly higher than those in summer, and the pollution levels also varied obviously in different layers of the sediments. Moreover, the pollution level of Cd was the most serious, as estimated by all three assessment methods.
heavy metal; hyporheic sediment; seasonal; liquid-solid two-phase; benthos activity; risk
BST-2/tetherin is an interferon-inducible antiviral protein that blocks the release of various enveloped viruses, including HIV-1. Hepatitis B virus (HBV), a major cause of liver disease, belongs to the Hepadnaviridae family of enveloped DNA viruses. Whether BST-2 regulates HBV production is largely unknown. In this report, we have demonstrated that HBV particle release is modulated by BST-2 in a cell type-dependent fashion. In HEK293T cells, ectopically expressed or interferon-induced BST-2 strongly inhibited HBV release. BST-2 co-localized with HBV surface protein at multivesicular bodies (MVBs) and physically interacted with HBV particles. However, exogenous BST-2-induced HBV restriction was weak in Huh-7 hepatoma cells, and the interferon-induced anti-HBV effect was independent of BST-2 induction in hepatic L02 cells. Notably, HBV could promote HIV-1 ΔVpu virus release from BST-2-positive HepG2 hepatoma cells but not HeLa cells, whereas Vpu failed to efficiently inhibit BST-2-induced HBV restriction. HBx exhibited an enhanced interaction and co-localization with BST-2 in hepatocytes. These observations indicate that BST-2 restricts HBV production at intracellular MVBs but is inactivated by HBV through a novel mechanism requiring hepatocyte-specific cellular co-factors or a hepatocyte-specific environment. Further understanding of BST-2-induced HBV restriction may provide new therapeutic targets for future HBV treatments.
The vasa vasorum of carotid artery plaque is a novel marker of accurately evaluating the vulnerability of carotid artery plaque, which was associated with symptomatic cerebrovascular and cardiovascular disease. The presence of ultrasound contrast agents in carotid artery plaque represents the presence of the vasa vasorum in carotid artery plaque because the ultrasound contrast agents are strict intravascular tracers. Therefore, contrast-enhanced ultrasound (CEUS) is a novel and safe imaging modality for evaluating the vasa vasorum in carotid artery plaque. However, there are some issues that needs to be assessed to embody fully the clinical utility of the vasa vasorum in carotid artery plaque with CEUS.
Vasa vasorum; Carotid artery; Plaque; Vulnerability; Contrast-enhanced ultrasound
This study assessed the effect of GLP-1 based therapies on atherosclerotic markers in type 2 diabetes patients. 31 studies were selected to obtain data after multiple database searches and following inclusion and exclusion criteria. Age and BMI of the participants of longitudinal studies were 59.8 ± 8.3 years and 29.2 ± 5.7 kg/m2 (Mean±SD). Average duration of GLP-1 based therapies was 20.5 weeks. Percent flow-mediated diameter (%FMD) did not change from baseline significantly but when compared to controls, %FMD increased non-significantly following GLP-1-based therapies (1.65 [−0.89, 4.18]; P = 0.2; REM) in longitudinal studies and increased significantly in cross sectional studies (2.58 [1.68, 3.53]; P < 0.00001). Intima media thickness decreased statistically non-significantly by the GLP-1 based therapies. GLP-1 based therapies led to statistically significant reductions in the serum levels of brain natriuretic peptide (−40.16 [−51.50, −28.81]; P < 0.0001; REM), high sensitivity c-reactive protein (−0.27 [−0.48, −0.07]; P = 0.009), plasminogen activator inhibitor-1 (−12.90 [−25.98, 0.18]; P=0.05), total cholesterol (−5.47 [−9.55, −1.39]; P = 0.009), LDL-cholesterol (−3.70 [−7.39, −0.00]; P = 0.05) and triglycerides (−16.44 [−25.64, −7.23]; P = 0.0005) when mean differences with 95% CI in the changes from baselines were meta-analyzed. In conclusion, GLP-1-based therapies appear to provide beneficial effects against atherosclerosis. More randomized data will be required to arrive at conclusive evidence.
To determine the difference of surgical induced astigmatism between conventional 20-gauge sutured vitrectomy and 23-gauge transconjunctival sutureless vitrectomy, and the influence of corneal pachymetry and intraocular pressure (IOP) on surgical induced astigmatism in diabetic patients.
This retrospective, consecutive case series consisted of 40 eyes of 38 diabetic subjects who underwent either 20-gauge or 23-gauge vitrectomy. The corneal curvature and thickness were measured with Scheimpflug imaging before surgery and 1wk; 1, 3mo after surgery. We compared the surgical induced astigmatism (SIA) on the true net power in 23-gauge group with that in 20-gauge group. We determined the correlation between corneal thickness change ratio, IOP and SIA measured by Pentacam.
The mean SIAs were 1.082±0.085 D (mean±SEM), 0.689±0.070 D and 0.459±0.063 D at postoperative 1wk; 1, 3mo respectively in diabetic subjects. The vitrectomy induced astigmatisms were declined significantly with time (F2,36=33.629, P=0.000) postoperatively. The 23-gauge surgery group induced significantly less astigmatism than 20-gauge surgery group (F-1,37=11.046, P=0.020). Corneal thickness in diabetes elevated after surgery (F3,78=10.532, P=0.000). The linear regression analysis at postoperatively 1wk went as: SIA=-4.519+4.931 change ratio (Port3) +0.026 IOP (R2=0.46, P=0.000), whereas the rate of corneal thickness change and IOP showed no correlation with the change of astigmatism at postoperatively 1 and 3mo.
There are significant serial changes in both 20-gauge and 23-gauge group in diabetic subjects. 23-gauge induce less astigmatism than 20-gauge and become stable more rapidly than 20-gauge. The elevation of corneal thickness and IOP was associated with increased astigmatim at the early postoperative stage both in 23-gauge and 20-gauge surgery group.
astigmatism; corneal pachymetry; vitrectomy; intraocular pressure; diabetes mellitus
Mitophagy is a specialized form of autophagy that selectively disposes of dysfunctional mitochondria. Delineating the molecular regulation of mitophagy is of great importance because defects in this process lead to a variety of mitochondrial diseases. Here we report that mice deficient for the mitochondrial protein, phosphoglycerate mutase family member 5 (PGAM5), displayed a Parkinson’s-like movement phenotype. We determined biochemically that PGAM5 is required for the stabilization of the mitophagy-inducing protein PINK1 on damaged mitochondria. Loss of PGAM5 disables PINK1-mediated mitophagy in vitro and leads to dopaminergic neurodegeneration and mild dopamine loss in vivo. Our data indicate that PGAM5 is a regulator of mitophagy essential for mitochondrial turnover and serves a cytoprotective function in dopaminergic neurons in vivo. Moreover, PGAM5 may provide a molecular link to study mitochondrial homeostasis and the pathogenesis of a movement disorder similar to Parkinson’s disease.
The Janus kinase-signal transducers and activators of transcription signaling pathway (JAK/STAT pathway) play an important role in proliferation of breast cancer cells. Previous data showed that inhibition of STAT3 suppresses the growth of breast cancer cells, but the associated mechanisms are not well understood. This study aims to investigate the effect and associated mechanisms of JAK/STAT pathway inhibitor AG490 on proliferation and suppression of breast cancer cells.
Materials and Methods:
CCK-8 assay and trypan blue exclusion assay were used to investigate the cytotoxicity of AG490 to MDA-MB-231 cells. Real-time PCR was used to detect the mRNA level of SARI (suppressor of AP-1, regulated by IFN). Western blot was used to analyze the protein levels of SARI, phospho-STAT3 and total STAT3. Luciferase reporter assay was adopted to explore the mechanism of SARI mRNA upregulation.
AG490 suppressed the proliferation of MDA-MB-231 cells in a dose-dependent manner. AG490 significantly up-regulated the mRNA and protein levels of SARI in MDA-MB-231 cells. Knockdown of SARI obviously attenuated AG490-induced growth suppression effect in MDA-MB-231 cells. Furthermore, AG490 dramatically enhanced the transcription activity of SARI promoter. But the transcription activity of truncated SARI promoter, which does not contain STAT3 binding site, cannot be activated by AG490 treatment.
We demonstrate in this study that AG490 suppresses the proliferation of MDA-MB-231 cells through transcriptional activation of SARI.
AG490; MDA-MB-231; Proliferation; SARI; STAT3
To study the role of c-Src kinase in prooxidant-induced stimulation of TLR4, we used LPS-EK and MPLA as TLR4 specific agonists and positive controls, and SIN-1 and PPC as prooxidant sources. We used HEK-Blue mTLR4 cell line that is stably transfected with mouse TLR4 and that expresses optimized SEAP reporter under the control of a promoter inducible by NF-κB transcription factor. The level of SEAP released due to TLR4 stimulation was a measure of NF-κB activation. Treatment with either the prooxidants or LPS-EK increased SEAP release and TNF-α production in these cells. These treatments also increased intracellular ROS accumulation with an enhanced production of nitric oxide and TBARS to confirm oxidant stress in these cells. Pretreatment with c-Src kinase inhibitors, PP2 and CA-pY, which act by different mechanisms, decreased these parameters. Pretreatment with SSG, a c-Src activator, enhanced the effects promoted by LPS-EK and prooxidants, and rescued cells from PP2- and Ca-pY-induced effects. Curiously, prooxidants but not TLR4 agonist increased the ratio of TNFα to IL-10 released suggesting that prooxidants can initiate and maintain an imbalance of TNFα production over IL-10. To different degrees, both prooxidant and TLR4 agonist increased formation of c-Src complexes with TLR4 and IκB-α as coimmunoprecipitates. Both prooxidant and TLR4 agonist increased c-Src phosphorylation of Tyr-42 residue in IκB-α, but prooxidant-induced effect was more robust and much longer lasting. Taken together, these studies provide a mechanism whereby c-Src assumes a central role in prooxidant-induced NF-κB activation in TLR4 signaling. Prooxidant-induced activation of TLR4 through c-Src/NFκB/IκB-α coupling provides a basis for a molecular dissection of the initiation and maintenance of sterile inflammation that may serve as a “pathophysiologic primer” for many diseases.
Toll-like receptor 4; c-Src; IκB-α; NF-κB; pathophysiologic primer; prooxidant; sterile inflammation