Toxicity and oxidative stress of HepG2 and HL-7702 cells induced by PAH4 using oil as a carrier.

Polycyclic aromatic hydrocarbons (PAHs), a widespread class of food pollutants, are commonly exposed to humans along with edible oil. The dietary exposure pattern of PAH4 was simulated to study the toxicity and oxidative stress of oil-based PAH4 on hepatocytes. The findings demonstrated that oil-based PAH4 induced cell viability and mitochondrial membrane potential decreased and promoted apoptosis and oxidative stress in a concentration-dependent manner. Benzo[a]pyrene had the strongest toxicity and HL-7702 cells were more sensitive to toxicity than HepG2 cells, due to differences in induced CYP1A enzyme activity. Oil-based PAH4 had greater cytotoxicity than PAH4, attributed to the synergistic effect of oil and PAH4. Furthermore, oil-based PAH4 induced oxidative stress in HepG2 and HL-7702 cells through the same AHR-Nrf2-KEAP1 pathway, which was elucidated by detecting genes and proteins expression. This study lays the foundation for elucidating the harm of dietary exposure to PAHs and reminds us that food composition may increase the harm of PAHs.

Combined toxicity of oil-based PAH4 mixtures on HL-7702 cells.

Polycyclic aromatic hydrocarbons (PAHs) as a group of prevalent persistent organic pollutants in the environment are always found as mixtures. The combined toxicity of oil-based PAH4 seems seldom to be mentioned. To evaluate the combined toxicity of oil-based PAH4 mixtures on HL-7702 cells, the effects of single, binary, ternary, and quaternary mixtures on cell viability were examined, and the concentration addition model and combination index (CI)-isobologram model were selected to predict the toxicological interactions of the mixtures. The results showed that the PAH4 mixtures had a concentration-dependent effect on cell viability. The CI model was more suitable for elucidating the toxicity interactions of mixtures. In addition, the combined toxicity of BaA + BaP and BaA + Chr + BbF + BaP was antagonistic, BaA + Chr, BaA + BbF, Chr + BbF, and BaA + Chr + BbF was synergistic, and the remaining mixtures shifted from antagonistic to synergistic. Antagonistic effects were observed in all mixtures containing BaP, indicating that oil-based PAH4 mixtures containing BaP had a mitigating effect on cytotoxicity. Furthermore, BbF was identified as playing a key role in the synergistic effects in binary and ternary mixtures. This study provided a new acknowledgment to assess the interactions of PAH4 mixtures which is helpful for further study of the toxicity risks in the environment.

Antioxidant capacity and interaction of endogenous phenolic compounds from tea seed oil.

Endogenous phenols play a significant role in delaying oil rancidity. In this study, the profile of 22 endogenous phenols was determined from tea seed oil by UPLC-MS/MS, of which 15 phenols were identified for the first time. Then seven phenols with high content and strong antioxidant capacity were selected to investigate interaction using the DPPH· and Rancimat. It was found that the interaction of combinations was inconsistent in different media. Combined quercetin + esculetin, caffeoyl tartaric acid + esculetin, caffeoyl tartaric acid + gentisic acid and esculetin + gentisic acid showed synergistic antioxidant effects in oil and ethanol systems. Moreover, through the evaluation of the lipid oxidation process, combined esculetin + gentisic acid exhibited the greatest synergistic antioxidant effect. Notably, combined quercetin + esculetin had an inhibitory effect on the formation of volatile compounds. These findings may provide a basis for explaining the oxidation stability of tea seed oil.

A Choline-Recognizing Monomeric Lysin, ClyJ-3m, Shows Elevated Activity against Streptococcus pneumoniae.

Streptococcus pneumoniae is a leading pathogen for bacterial pneumonia, which can be treated with bacteriophage lysins harboring a conserved choline binding module (CBM). Such lysins regularly function as choline-recognizing dimers. Previously, we reported a pneumococcus-specific lysin ClyJ comprising the binding domain from the putative endolysin gp20 from the Streptococcus phage SPSL1 and the CHAP (cysteine, histidine-dependent amidohydrolase/peptidase) catalytic domain from the PlyC lysin. A variant of ClyJ with a shortened linker, i.e., ClyJ-3, shows improved activity and reduced cytotoxicity. Resembling typical CBM-containing lysins, ClyJ-3 dimerized upon binding with choline. Herein, we further report a choline-recognizing variant of ClyJ-3, i.e., ClyJ-3m, constructed by deleting its C-terminal tail. Biochemical characterization showed that ClyJ-3m remains a monomer after it binds to choline yet exhibits improved bactericidal activity against multiple pneumococcal strains with different serotypes. In an S. pneumoniae-infected bacteremia model, a single intraperitoneal administration of 2.32 µg/mouse of ClyJ-3m showed 70% protection, while only 20% of mice survived in the group receiving an equal dose of ClyJ-3 (P < 0.05). A pharmacokinetic analysis following single intravenously doses of 0.29 and 1.16 mg/kg of ClyJ-3 or ClyJ-3m in BALB/c mice revealed that ClyJ-3m shows a similar half-life but less clearance and a greater area under curve than ClyJ-3. Taken together, the choline-recognizing monomer ClyJ-3m exhibited enhanced bactericidal activity and improved pharmacokinetic proprieties compared to those of its parental ClyJ-3 lysin. Our study also provides a new way for rational design and programmed engineering of lysins targeting S. pneumoniae.

The association between occupational-related mechanical stress and radiographic damage in psoriatic arthritis.

OBJECTIVE: To assess the association between occupational-related mechanical factors and the severity of radiographic peripheral and axial joint damage in patients with longstanding Psoriatic Arthritis (PsA). METHODS: Patients with longstanding PsA (disease duration≥10 years) were identified from a prospective longitudinal cohort. Using an occupation history questionnaire, patients were asked to report all paid employments since the age of 18. The key predictor variables included various occupational-related mechanical exposures. A job classification database was used to rate the level of exposure to various occupational physical activities. The outcomes were the extent of radiographic damage in the peripheral and axial joints, as measured by the modified Steinbrocker score (mSS), and the modified Stokes Ankylosing Spondylitis Spine Score (mSASSS). The association between the predictors and outcome variables was assessed by negative binomial regression models after adjusting for potential confounding variables. RESULTS: A total of 307 eligible patients were analyzed. In the multivariable analysis, exposure to prolonged repetitive hand movements (exp(ß) 1.17 (95% 1.07, 1.28)) and occupations that required higher level of finger dexterity (exp(ß) 1.27 (95% 1.09, 1.47)) were associated with a higher mSS. With regards to axial damage, none of the occupational exposures or workers abilities was associated with mSASSS. CONCLUSION: High level of occupation-related mechanical stress is associated with increased radiographic peripheral joint damage among patients with longstanding PsA. This finding supports the potential role of micro-trauma in the pathogenesis of PsA.

MiR-122 promotes renal cancer cell proliferation by targeting Sprouty2.

MicroRNAs are short non-coding RNAs, which have been implicated in several biological processes. Aberrant expression of the microRNA miR-122 has frequently been reported in malignant cancers. However, the mechanism underlying the effects of miR-122 in renal cell carcinoma remains unknown. The aim of this study was to determine the biological function of miR-122 in renal cell carcinoma and to identify a novel molecular target regulated by miR-122. We measured the expression levels of Sprouty2 in six renal cell carcinoma tissue samples and adjacent non-tumor tissues by western blot analysis. We then used reverse transcription polymerase chain reaction to measure miR-122 levels in 40 primary renal cell carcinoma and adjacent non-malignant tissue samples. The effects of miR-122 down-regulation or Sprouty2 knockdown were evaluated via Cell Counting Kit-8 assay, flow cytometry, and western blot analysis. The relationship between miR-122 and Sprouty2 was determined using dual-luciferase reporter assays. Sprouty2 was down-regulated in renal cell carcinoma tissue samples compared with adjacent normal tissue. In contrast, miR-122 was up-regulated in primary renal cell carcinoma tissue samples compared with adjacent normal tissue samples. Down-regulation of miR-122 substantially weakened the proliferative ability of renal cell carcinoma cell lines in vitro. In contrast, Sprouty2 knockdown promoted the in vitro proliferation of renal cell carcinoma cell lines. The spry2 gene could therefore be a direct target of miR-122. In conclusion, miR-122 could act as a tumor promoter and potentially target Sprouty2. MiR-122 promotes renal cell carcinoma cell proliferation, migration, and invasion and could be a molecular target in novel therapies for renal cell carcinoma.

Feasibility of triphasic CT with a modified two-point Patlak plot to determine spit kidney glomerular filtration rate in clinical practice.

PURPOSE: To investigate whether triphasic CT with a simplified Patlak plot can be used in clinical practice for the estimate of split kidney glomerular filtration rate (SKGFR). MATERIALS AND METHODS: The animal experiment included 15 rabbits that underwent 40 dynamic contrast-enhanced CT scans of the kidneys with 1.5 s time interval. Patlak-derived SKGFR was obtained using standard forty-point, two-point (unenhanced phase, arterial phase t α, and portovenous phase t ß), and a modified two-point (MTP) (unenhanced, t α, t ß, and a virtual t τ [t τ = (t α + t ß)/2]) image data, respectively. The MTP-Patlak plot approach was then validated in 13 patients who underwent a triphasic renal contrast-enhanced CT examination. SKGFR measured by 99mTc-DTPA clearance was as a standard reference. RESULTS: MTP-Patlak significantly reduced input function errors than two-point Patlak (21.1 ± 16.2 % vs 30.8 ± 15.2 %, p < 0.01) and showed good concordance with standard Patlak for measurement of SKGFR in animal experiment (1.20 ± 0.38 mL/g/min vs 1.51 ± 0.43 mL/g/min; linear correlation coefficient r = 0.87, p < 0.001). Human study showed that mean SKGFR was 45.7 mL/min (range, 26.5-86.2 mL/min) obtained from 99mTc-DTPA, and 38.2 mL/min (range, 18.6-79.3 mL/min) obtained from triphasic CT using MTP-Patlak plot. Linear correlation between the two methods was r = 0.75 (p < 0.01). The mean difference between SKGFRs as determined with the two methods was 7.4 ± 9.0 mL/min. CONCLUSION: The MTP-Patlak approach, featured with simplicity, is feasible in a clinically indicated CT examination for the evaluation of split renal function.

Transforming Growth Factor-ß1 Induces Endothelial-to-Mesenchymal Transition via Akt Signaling Pathway in Renal Transplant Recipients with Chronic Allograft Dysfunction.

BACKGROUND Chronic allograft dysfunction (CAD) is the major cause of chronic loss of allograft in kidney transplant recipients. Kidney interstitial fibrosis is identified to be strongly associated with CAD in kidney transplantation. Recently, endothelial-to-mesenchymal transition (EndMT) has been identified as one of the potential mechanisms in kidney interstitial fibrosis. MATERIAL AND METHODS Kidney tissue samples from 25 renal transplant recipients (RTRs) with CAD and healthy volunteers were collected for HE (hematoxylin-eosin), Masson trichrome, and immunohistochemical staining, and indirect immunofluorescence double-staining assay. Moreover, human umbilical vascular endothelial cells (HUVECs) were cultured and treated with TGF-ß1 at different doses or intervals. The protein expressions of α-SMA and CD31 were determined by Western blot assay. Furthermore, potential signaling pathways involved in EndMT induced by TGF-ß1were also investigated by Western blotting. RESULTS Typical interstitial fibrosis was observed in transplanted renal tissues from the CAD group. We also found a significant increase of TGF-ß1 expression in renal tissues from RTRs with CAD compared with the normal group. Moreover, significant over-expressions of α-SMA, collagen-I, and collagen-III and under-expression of CD31 were detected in kidney specimens of the CAD group. Similar expressive tendencies of α-SMA and CD31 proteins were found in HUVECs treated with TGF-ß1 in both time-dependent and dose-dependent manners. The activation of the Akt signaling pathway was found in HUVECs induced by TGF-ß1 and selective inhibitors. CONCLUSIONS EndMT was observed in kidney tissues from RTRs with CAD, and TGF-ß1 can induce the process of EndMT in both time-dependent and does-dependent manners through the Akt signaling pathway.