Activation of aryl hydrocarbon receptor by azatyrosine-phenylbutyric hydroxamide inhibits progression of diabetic retinopathy mice.

Diabetic retinopathy (DR) is a severe consequence of long-term diabetes mellitus and may lead to vision loss. Retinal pigment epithelial (RPE) cells are a diverse group of retinal cells with varied metabolic and functional roles. In hypoxic conditions, RPE cells have been shown to produce angiogenic factors, such as vascular endothelial growth factor (VEGF), which is regulated by hypoxia-inducible factor 1-alpha (HIF1A). VEGF plays a crucial role in angiogenesis in DR. In the present study, we investigated whether azatyrosine-phenylbutyric hydroxamide (AZP) has therapeutic effect on DR therapy. In this study, we treated high glucose-activated human retinal pigment epithelial cells (ARPE-19) with and without AZP. The effector proteins were evaluated using western blotting. In the in vivo study, AZP was administered to the db/db mice as a DR animal model. Moreover, invasive imaging techniques such as optical coherence tomography (OCT), fundus photography, and fundus fluorescein angiography (FFA) were performed on the mice to assess DR progression. We found that treatment of AZP for 12 weeks reversed increasing DR retinal alterations in db/db mice, decreasing vascular density, retinal blood perfusion, retinal thickness, decreasing DR lesion, lipofuscin accumulation, HIF1A, VEGF, and inflammation factor expression. In addition, AZP treatment could activate the aryl hydrocarbon receptor AHR and reverse the high-glucose-induced HIF1A and VEGF in ARPE-19 cells and db/db mice. In conclusion, AZP activated AHR while inhibiting HIF1A and VEGF. This study indicates that AZP may be a promising therapeutic agent for treating DR.

Blue light exposure collapses the inner blood-retinal barrier by accelerating endothelial CLDN5 degradation through the disturbance of GNAZ and the activation of ADAM17.

Blue light is part of the natural light spectrum that emits high energy. Currently, people are frequently exposed to blue light from 3C devices, resulting in a growing incidence of retinopathy. The retinal vasculature is complex, and retinal vessels not only serve the metabolic needs of the retinal sublayers, but also maintain electrolyte homeostasis by forming the inner blood-retinal barrier (iBRB). The iBRB, which is primarily composed of endothelial cells, has well-developed tight junctions. However, with exposure to blue light, the risks of targeting retinal endothelial cells are currently unknown. We found that endothelial claudin-5 (CLDN5) was rapidly degraded under blue light, coinciding with the activation of a disintegrin and metalloprotease 17 (ADAM17), even at non-cytotoxic lighting. An apparently broken tight junction and a permeable paracellular cleft were observed. Mice exposed to blue light displayed iBRB leakage, conferring attenuation of the electroretinogram b-wave and oscillatory potentials. Both pharmacological and genetic inhibition of ADAM17 remarkably alleviated CLDN5 degradation induced by blue light. Under untreated condition, ADAM17 is sequestered by GNAZ (a circadian-responsive, retina-enriched inhibitory G protein), whereas ADAM17 escapes from GNAZ by blue light illuminance. GNAZ knockdown led to ADAM17 hyperactivation, CLDN5 downregulation, and paracellular permeability in vitro, and retinal damage mimicked blue light exposure in vivo. These data demonstrate that blue light exposure might impair the iBRB by accelerating CLDN5 degradation through the disturbance of the GNAZ-ADAM17 axis.

Valacyclovir-associated neurotoxicity among patients on hemodialysis and peritoneal dialysis: A nationwide population-based study.

Whether valacyclovir-associated neurotoxicity (VAN) occurs more frequently in patients with end-stage renal disease (ESRD) on dialysis is unknown. This is the first population-based study to examine the risk of VAN associated with ESRD patients on dialysis. Among 2,284,800 patients diagnosed as having herpes zoster from 2002 to 2016, patients with ESRD on dialysis and individuals with normal renal function were enrolled in this study. Following propensity score matching, we compared the risk of altered mental status between valacyclovir users and non-users in the ESRD and normal renal function cohorts over a 30-day follow-up period. In the ESRD cohort, the incidence of altered mental status was 1.68 and 0.52 per 1,000 person-day in valacyclovir users and non-users, respectively, with an adjusted hazard ratio (HR) of 3.22 (95% confidence interval [CI]: 2.04-4.99, P < 0.001). The incidence of altered mental status of valacyclovir users on hemodialysis (HD) and peritoneal dialysis (PD) was higher than that of non-users. The adjusted HR was 3.20 (95% CI: 1.98-5.15, P < 0.001) for those on HD and 3.44 (95% CI: 1.13-10.49, P = 0.030) for those with PD. However, altered mental status was not observed in patients on HD receiving ≤500 mg of valacyclovir three times per week or in those on PD receiving ≤500 mg of valacyclovir per day. The findings demonstrate that adjusting the valacyclovir dosage and monitoring VAN in patients with HD and PD who have herpes zoster is crucial.

Benefits of Valsartan and Amlodipine in Lipolysis through PU.1 Inhibition in Fructose-Induced Adiposity.

High fructose intake has been implicated in obesity and metabolic syndrome, which are related to increased cardiovascular mortality. However, few studies have experimentally examined the role of renin-angiotensin system blockers and calcium channel blockers (CCB) in obesity. We investigated the effects of valsartan (an angiotensin II receptor blocker) and amlodipine (a CCB) on lipolysis through the potential mechanism of PU.1 inhibition. We observed that high fructose concentrations significantly increased adipose size and triglyceride, monoacylglycerol lipase, adipose triglyceride lipase, and stearoyl-CoA desaturase-1 (SCD1), activating transcription factor 3 and PU.1 levels in adipocytes in vitro. Subsequently, PU.1 inhibitor treatment was able to reduce triglyceride, SCD1, and PU.1 levels. In addition, elevated levels of triglyceride and PU.1, stimulated by a high fructose concentration, decreased with valsartan and amlodipine treatment. Overall, these findings suggest that high fructose concentrations cause triacylglycerol storage in adipocytes through PU.1-mediated activation. Furthermore, valsartan and amlodipine treatment reduced triacylglycerol storage in adipocytes by inhibiting PU.1 activation in high fructose concentrations in vitro. Thus, the benefits of valsartan and amlodipine in lipolysis may be through PU.1 inhibition in fructose-induced adiposity, and PU.1 inhibition might have a potential therapeutic role in lipolysis in fructose-induced obesity.

Association Between DPP-4 Inhibitors and Events of Colorectal and Liver Cancers in Patients With Diabetes Receiving Second-Line Agents: A Nested Case-Control Study.

Objective: Plasma dipeptidyl peptidase-4 (DPP4) levels were significantly lower in patients with colorectal and liver cancers, and animal studies also showed DPP4 inhibitors (DPP4is) have procarcinogenic effects in colorectal cancer. Until now, whether DPP4is therapy affects the progression of liver cancer and colorectal cancer in patients with T2DM has not been well investigated. We investigated the association between cumulative defined daily dose (cDDD) of DPP4is exposure and risks of liver and colorectal cancers in patients with type 2 diabetes. Materials and Methods: We identified 268,520 patients with diabetes receiving DPP4is as second-line agents between March 1, 2009, and December 31, 2013, from Taiwan's National Health Insurance Research Database, Taiwan Cancer Registry, and National Death Registry of Taiwan. The amount of DPP4is were divided into three groups (low, medium, and high) based on the interquartile range of the cDDD of the DPP4is. Results: The data showed that the low cDDD of DPP-4is was associated with a reducing risk of colorectal cancer [adjusted odds ratio (OR), 0.49; 95% CI, 0.32-0.75; P=0.001]. However, the high cDDD of DPP-4is was associated with an increasing risk of colorectal cancer (adjusted OR, 1.86; 95% CI, 1.32-2.61; P<0.001). No association between DPP4is use and liver cancer risk was observed. Conclusions: This nested case study revealed a J-shaped association between the cDDD of DPP-4is and colorectal cancer risk, but not liver cancer risk. Therefore, the effects of long-term DPP4is use on colorectal cancer risk warrant further study.

Higher Risk of Gastric Helicobacter pylori Infection in Patients with Periodontitis: A Nationwide Population-Based Retrospective Cohort Study in Taiwan.

Periodontitis is the most prevalent chronic inflammatory oral disease that is characterized by tooth loss and is commonly associated with several systemic inflammatory diseases. Some epidemiological studies suggest that those suffering from periodontitis might be at a greater risk of developing gastric Helicobacter pylori (Hp) infection; however, evidence that showing the association between periodontitis and the risk of gastric Hp infection is less clear. We conducted a large-scale, population-based study in Taiwan with a 13-year follow-up period to evaluate the risk of gastric Hp in a periodontitis patient cohort. To conduct this study, we used epidemiological data from the Taiwanese Longitudinal National Health Insurance Research Database (NHIRD) from 2000 to 2013. We selected 134,474 participants (64,868 males and 69,606 females with a minimum age of 20 years), with and without periodontitis, and matched patient cohort groups for age, sex, index year, and co-morbidities. The Cox proportional hazards regression model was used to examine the risk of gastric Hp infection in patients with periodontitis. Patients with periodontitis exhibited a higher risk of developing gastric Hp infection compared to those individuals/groups without periodontitis (1.35 vs. 0.87 per 1000 person-years, adjusted the hazards ratio (aHR 1.52), and 95% confidence intervals (CIs) 1.38-1.67, p < 0.001). The risk of gastric Hp infection persisted even after stratifying by age (aHR = 1.96 (1.79-2.13) for 50-64 years and 1.70 (1.49-1.94) for ≥65 years), gender (aHR = 1.20 (1.11-1.29) for men), and presence of comorbidities of hypertension (aHR = 1.24 (1.11-1.38)), hyperlipidemia (aHR = 1.28 (1.14-1.42)), COPD (aHR = 1.45 (1.31-1.61)), CLD (aHR = 1.62 (1.47-1.77)) and CKD (aHR = 1.44 (1.04-1.99)). Overall, our findings showed that periodontitis patients have a greater risk for gastric Hp than individuals without periodontitis. Clinicians should perform regular good oral hygiene practices, along with newer treatments, for patients with periodontitis, especially those at higher risk of gastric Hp infection.

Aryl Hydrocarbon Receptor Defect Attenuates Mitogen-Activated Signaling through Leucine-Rich Repeats and Immunoglobulin-like Domains 1 (LRIG1)-Dependent EGFR Degradation.

Aryl hydrocarbon receptor (AHR) genomic pathway has been well-characterized in a number of respiratory diseases. In addition, the cytoplasmic AHR protein may act as an adaptor of E3 ubiquitin ligase. In this study, the physiological functions of AHR that regulate cell proliferation were explored using the CRISPR/Cas9 system. The doubling-time of the AHR-KO clones of A549 and BEAS-2B was observed to be prolonged. The attenuation of proliferation potential was strongly associated with either the induction of p27Kip1 or the impairment in mitogenic signal transduction driven by the epidermal growth factor (EGF) and EGF receptor (EGFR). We found that the leucine-rich repeats and immunoglobulin-like domains 1 (LRIG1), a repressor of EGFR, was induced in the absence of AHR in vitro and in vivo. The LRIG1 tends to degrade via a proteasome dependent manner by interacting with AHR in wild-type cells. Either LRIG1 or a disintegrin and metalloprotease 17 (ADAM17) were accumulated in AHR-defective cells, consequently accelerating the degradation of EGFR, and attenuating the response to mitogenic stimulation. We also affirmed low AHR but high LRIG1 levels in lung tissues of chronic obstructive pulmonary disease (COPD) patients. This might partially elucidate the sluggish tissue repairment and developing inflammation in COPD patients.

Exosomal tumor necrosis factor-α from hepatocellular cancer cells (Huh-7) promote osteoclast differentiation.

Bone is the common extra-hepatic site for cancer metastasis. Hepatic cancer is associated with a higher incidence of pathological fracture. However, this important regulatory mechanism remains unexplored. Thus, exosome-mediated cell-cell communication between hepatocellular cancer and bone might be key to osteolytic bone destruction. Huh-7 exosomes were characterized for size and exosome marker expressions (CD63, Alix). Exosome mediated osteoclast differentiation in the RAW 264.7 cells was monitored from day 1 to 6 and multinucleated osteoclast formation and bone resorption activity were analyzed. The osteoclastogenic factor expressions in the exosomes and osteoclast differentiation markers such as tumor necrosis factor receptor 6 (TRAF6), nuclear factor κB (NF-κB), nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1), and cathepsin K (CTSK) were analyzed using western blot. Exosomes released by liver cancer cells (Huh-7) promoted osteoclast differentiation in RAW 264.7 cells. Analysis of osteoclastogenic factors in the exosomes showed that exosomes were specifically enriched with tumor necrosis factor α (TNF-α). Huh-7 exosomes promoted osteoclast differentiation by significantly increasing the number of TRAP-positive multi nucleated osteoclasts and resorption pits. Importantly, exosomes upregulated osteoclast markers TRAF6, NF-κB, and CTSK expressions. Further, neutralizing exosomal TNF-α reverted exosome-mediated osteoclast differentiation in RAW 264.7 cells. Collectively, our findings show that cellular communication of exosomal TNF-α from hepatocellular cancer cells (Huh-7) regulates osteoclast differentiation through NF-κB/CTSK/TRAP expressions. Thus, exosomal TNF-α might act as an important therapeutic target to prevent hepatocellular cancer mediated pathological bone disease.

Titanium dioxide nanoparticles impair the inner blood-retinal barrier and retinal electrophysiology through rapid ADAM17 activation and claudin-5 degradation.

BACKGROUND: Depending on their distinct properties, titanium dioxide nanoparticles (TiO2-NPs) are manufactured extensively and widely present in our daily necessities, with growing environmental release and public concerns. In sunscreen formulations, supplementation of TiO2-NPs may reach up to 25% (w/w). Ocular contact with TiO2-NPs may occur accidentally in certain cases, allowing undesirable risks to human vision. This study aimed to understand the barrier integrity of retinal endothelial cells in response to TiO2-NP exposure. bEnd.3 cells and human retinal endothelial cells (HRECs) were exposed to TiO2-NP, followed by examination of their tight junction components and functions. RESULTS: TiO2-NP treatment apparently induced a broken structure of the junctional plaques, conferring decreased transendothelial electrical resistance, a permeable paracellular cleft, and improved cell migration in vitro. This might involve rapid activation of metalloproteinase, a disintegrin and metalloproteinase 17 (ADAM17), and ADAM17-mediated claudin-5 degradation. For the in vivo study, C57BL/6 mice were administered a single dose of TiO2-NP intravitreally and then subjected to a complete ophthalmology examination. Fluorescein leakage and reduced blood flow at the optical disc indicated a damaged inner blood-retinal barrier induced by TiO2-NPs. Inappreciable change in the thickness of retinal sublayers and alleviated electroretinography amplitude were observed in the TiO2-NP-treated eyes. CONCLUSIONS: Overall, our data demonstrate that TiO2-NP can damage endothelial cell function, thereby affecting retinal electrophysiology.

Periodontitis and the subsequent risk of glaucoma: results from the real-world practice.

Periodontitis is a multifactorial inflammatory disease that can cause tooth loss and contribute to systemic inflammation. It is suggested that periodontitis may be associated with the development of glaucoma. Based on data from Taiwan's National Health Insurance Research Database, a retrospective cohort study was conducted to investigate the risk of developing glaucoma in patients with periodontitis. The periodontitis cohort consisted of newly diagnosed adult patients (n = 194,090, minimum age = 20 years) between 2000 and 2012. The comparison group included age-, gender-, and diagnosis date-matched people without periodontitis (n = 194,090, minimum age = 20 years). Incident glaucoma was monitored until the end of 2013. Hazard ratios (HRs) with confidence intervals (CIs) were established based on the Cox proportional hazard models. The risk of developing glaucoma was higher in patients with periodontitis than those without periodontitis (31.2 vs. 23.3 patients per 10,000 person-years, with an adjusted HR of 1.26 [95% CI 1.21-1.32]). A high risk was evident even after stratifying by age (adjusted HRs = 1.34 [1.26-1.44] for ages 20-49, 1.24 [1.13-1.36] for ages ≥ 65, and 1.20 [1.12-1.29] for ages 50-64 years), sex (adjusted HRs = 1.33 [1.24-1.41] and 1.21 [1.14-1.28] for men and women, respectively), presence of comorbidity (adjusted HRs = 1.38 [1.29-1.47] and 1.18 [1.12-1.25] for without and with comorbidity, respectively), and corticosteroid use (adjusted HRs = 1.27 [1.21-1.33] and 1.21 [1.08-1.35] for without and with corticosteroid use, respectively). Specifically, patients with periodontitis exhibited a significantly high risk of primary open-angle glaucoma (adjusted HR = 1.31 [1.21-1.32]) but not for primary closed-angle glaucoma (adjusted HR = 1.05 [0.94-1.17]). People with periodontitis are at a greater risk of glaucoma than individuals without periodontitis. Ocular health should be emphasized for such patients, and the underlying mechanisms need further investigation.

Aryl hydrocarbon receptor deficiency enhanced airway inflammation and remodeling in a murine chronic asthma model.

The aryl hydrocarbon receptor (AhR) is a ligand-dependent-activated transcriptional factor that regulates the metabolism of xenobiotic and endogenous compounds. Recent studies have shown that AhR is a novel master regulator of the mucosal immune system, including lungs and intestine. To elucidate the role of AhR in chronic severe asthma, AhR wild-type and knockout mice (AhR-/- ) were sensitized and challenged with ovalbumin for 4 weeks. To uncover the underlying mechanisms, inflammatory cells profile and cytokines production were analyzed in bronchial lavage fluid (BALF) and lung tissue. Compared to wild-type mice, AhR-/- mice had exacerbated asthma symptoms, including airway inflammation, mucus production, airway hyperresponsiveness, and airway remodeling. BALF monocytes, neutrophils, eosinophils, and lymphocytes were all enhanced in OVA-immunized AhR-/- mice. In OVA-immunized AhR-/- mice, T helper (Th) 17 cell-specific cytokine IL-17A, as well as airway remodeling factors, including epithelial-mesenchymal transition (EMT) markers and vascular endothelial growth factor (VEGF), were all enhanced in lung tissue. Moreover, human cohort studies showed that AhR gene expression in bronchial epithelial cells decreases in severe asthma patients. Loss of AhR leads to worsening of allergic asthma symptoms, indicating its importance in maintaining normal lung function and mediating disease severity.

The Powdered Root of Eurycoma longifolia Jack Improves Beta-Cell Number and Pancreatic Islet Performance through PDX1 Induction and Shows Antihyperglycemic Activity in db/db Mice.

Non-insulin-dependent diabetes mellitus (NIDDM) is a common metabolic disorder worldwide. In addition to the chief feature of long-standing hyperglycemia, dyslipidemia, hyperinsulinemia, and a number of complications develop in parallel. It is believed that an adequate control of blood glucose levels can cause these complications to go into remission. This study was performed to evaluate the antidiabetic activity of Eurycoma longifolia Jack (EL) in vivo. The blood-glucose-lowering activity of EL was studied in db/db mice administered crude powdered EL root (25, 50, and 100 mg/kg) orally for eight weeks. At the end of the study, HbA1c, insulin, plasma lipid levels, and histopathology were performed. Powdered EL root showed significant antihyperglycemic activity along with the control of body weight. After eight weeks of treatment, both the blood cholesterol level and the glycogen deposit in hepatocytes were remarkably lower, whereas the secreting insulin level was elevated. An improvement in islet performance was manifested as an increase in beta-cell number and pancreatic and duodenal homeobox 1 (PDX1) expression. Neogenesis or formation of new islets from pancreatic duct epithelial cells seen in the EL-treated group was encouraging. This study confirms the antihyperglycemic activity of EL through PDX1-associated beta-cell expansion resulting in an enhancement of islet performance.

The Contribution of Interleukin-12A Genotypes to Oral Cancer Risk in Taiwanese.

BACKGROUND/AIM: Oral cancer incidence is highest worldwide in Taiwan, and practical markers for personalized therapeutic strategies such as immunotherapies, is lacking. Interleukin-12 (IL12) is a cytokine that is reported to exhibit potent tumoricidal effects, however, its genotypic contribution to oral cancer is still largely unknown. We aimed to examine whether IL12A rs568408 and rs2243115 genotypes are associated with oral cancer risk in Taiwan. MATERIALS AND METHODS: Genotypic characteristics of IL12A were determined among 958 oral cancer cases and age- and gender-matched individuals via typical polymerase chain reaction-restriction fragment length polymorphism methodology. RESULTS: The variant genotypes of IL12A rs568408 and rs2243115 were not found to be significantly associated with elevated oral cancer risk (all p>0.05). Moreover, there was no interaction between IL12A genotypes and personal smoking, alcohol drinking and betel quid chewing behaviors (all p>0.05). CONCLUSION: IL12A rs568408 and rs2243115 genotypes may not serve as good predictors for oral cancer risk.

The functional interplay of lncRNA EGOT and HuR regulates hypoxia-induced autophagy in renal tubular cells.

Autophagy, an important cellular homeostatic mechanism regulates cell survival under stress and protects against acute kidney injury. However, the role of long noncoding RNA (lncRNA) in autophagy regulation in renal tubular cells (HK-2) is unclear. The study was aimed to understand the importance of lncRNA in hypoxia-induced autophagy in HK-2 cells. LncRNA eosinophil granule ontogeny transcript (EGOT) was identified as autophagy-associated lncRNA under hypoxia. The lncRNA EGOT expression was significantly downregulated in renal tubular cells during hypoxia-induced autophagy. Gain- and loss-of-EGOT functional studies revealed that EGOT overexpression reduced autophagy by downregulation of ATG7, ATG16L1, LC3II expressions and LC 3 puncta while EGOT knockdown reversed the suppression of autophagy. Importantly, RNA-binding protein, (ELAVL1)/Hu antigen R (HuR) binds and stabilizes the EGOT expression under normoxia and ATG7/16L1 expressions under hypoxia. Furthermore, HuR mediated stabilization of ATG7/16L1 expressions under hypoxia causes a decline in EGOT levels and thereby promotes autophagy. Altogether, the study first reveals the functional interplay of lncRNA EGOT and HuR on the posttranscriptional regulation of the ATG7/16L1 expressions. Thus, the HuR/EGOT/ATG7/16L1 axis is crucial for hypoxia-induced autophagy in renal tubular cells.

Down-regulation of aryl hydrocarbon receptor intensifies carcinogen-induced retinal lesion via SOCS3-STAT3 signaling.

The aryl hydrocarbon receptor (AHR) is a ligand-activated receptor that regulates the metabolism of several xenobiotics and participates in ocular inflammation. Although severe inflammation is a major risk of retinal damage, the underlying mechanism is not well established. In this study, to elucidate how AHR mediates inflammation homeostasis, we hypothesized that AHR expression may diminish during long-term exposure to benzo [a] pyrene (B [a]P), a carcinogen in cigarette smoke. The blockage of AHR function considerably impaired suppressor of cytokine signaling 3 (SOCS3) negative feedback regulation and upregulated B [a]P-induced pro-inflammation. Signal transducer and activator of transcription 3 (STAT3) was activated by B [a] P due to AHR dysfunction in human adult retinal pigment epithelial cells (ARPE-19). The STAT3-inducible element revealed higher activity in AHR knockout cells with B [a] P treatment, but not in wild type ARPE-19 cells. Moreover, AHR dysfunction led to STAT3 hypo-ubiquitination and changed the STAT3-SOCS3 interaction. Increased STAT3-SOCS3 complex during AHR dysfunction by B [a] P was suppressed by nifuroxazide in ARPE-19 cells. Furthermore, the in vivo results showed that STAT3 inhibition during AHR impairment by long-term B [a] P exposure preserved the retina thickness and reversed the visual function in male C57Bl/6 mice. Overall, long-term B [a] P exposure may attenuate AHR function, dysregulating the homeostasis of the SOCS3-STAT3 axis with intensive STAT3 activation. This finding is significant given that the disintegration of the AHR-SOCS3 axis is a sensitive factor involved in AMD-like lesion development in the retina, revealing that the low AHR level may be associated with cigarette smoking or xenobiotics exposure, causing retina inflammation and damage.

Aza-PBHA, a potent histone deacetylase inhibitor, inhibits human gastric-cancer cell migration via PKCα-mediated AHR-HDAC interactions.

Recently, histone deacetylase inhibitors (HDACi) have become widely used in anti-cancer treatment; however, due to acquired drug resistance and their relatively low specificity, they are largely ineffective against late-stage cancer. Thus, it is critical to elucidate the molecular mechanisms underlying these issues, so as to identify novel therapeutic targets to prevent late-stage cancer progression and resistance acquisition. The present study investigated the Aryl hydrocarbon receptor (AHR), that has been shown to mediate histone acetylation by regulating histone deacetylase (HDAC) activity during HDACi treatment in human gastric-cancer cell lines (i.e. AGS and NCI-N87 cells). The potent HDACi, Aza-PBHA, was thus shown to upregulate AHR expression in both AGS and NCI-N87 cell lines, and to increase histone acetylation levels by facilitating AHR/HDAC interactions. Conversely, AHR knockdown increased HDAC activity. Aza-PBHA also increased PKCα phosphorylation and membrane translocation; however, interestingly, PKCα inhibition reduced the Aza-PBHA-increased AHR and histone acetylation levels, and inhibited the formation of the AHR/HDAC complex, likely upregulating Aza-PBHA-inhibited cell migration. Thus, our results suggest that Aza-PBHA treatment increased AHR levels to suppress HDAC activity, and inhibited cell migration by activating PKCα activation. These findings support the use of drugs to control AHR-related epigenetic regulation as a promising potential method to prevent acquired resistance to cancer treatments.

The Joint Effect of Interleukin-12B rs3212227 Genotype and Behavioral Factors on Oral Cancer Risk in Taiwanese.

BACKGROUND/AIM: Oral cancer is of the highest incidence worldwide in Taiwan, and a better marker for personalized therapeutic strategies such as immunotherapies is urgently needed. Interleukin-12 (IL12) is a cytokine that has been reported to exhibit potent tumoricidal effects, however, its genotypic contribution to oral cancer is still largely unknown. The current study aimed at investigating whether IL12B rs3212227 genotype is associated with oral cancer in Taiwan. MATERIALS AND METHODS: Genotypic characteristics of IL12B rs3212227 were determined among 958 oral cancer cases and age- and gender-matched individuals via typical polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methodology. RESULTS: The AA, AC and CC genotypes of IL12B rs3212227 were 38.2, 38.9 and 22.9% in the case group and 36.2, 41.5 and 22.3% in the control group (p=0.5189), respectively. CONCLUSION: IL12B rs3212227 genotype was associated with oral cancer risk only in betel quid chewers.

Correction to: Inhaled gold nanoparticles cause cerebral edema and upregulate endothelial aquaporin 1 expression, involving caveolin 1 dependent repression of extracellular regulated protein kinase activity.

It was highlighted that the original article [1] contained the wrong Fig. 1.

Inhaled gold nanoparticles cause cerebral edema and upregulate endothelial aquaporin 1 expression, involving caveolin 1 dependent repression of extracellular regulated protein kinase activity.

BACKGROUND: Gold nanoparticles (Au-NPs) have extensive applications in electronics and biomedicine, resulting in increased exposure and prompting safety concerns for human health. After absorption, nanoparticles enter circulation and effect endothelial cells. We previously showed that exposure to Au-NPs (40-50 nm) collapsed endothelial tight junctions and increased their paracellular permeability. Inhaled nanoparticles have gained significant attention due to their biodistribution in the brain; however, little is known regarding their role in cerebral edema. The present study investigated the expression of aquaporin 1 (AQP1) in the cerebral endothelial cell line, bEnd.3, stimulated by Au-NPs. RESULTS: We found that treatment with Au-NPs induced AQP1 expression and increased endothelial permeability to water. Au-NP exposure rapidly boosted the phosphorylation levels of focal adhesion kinase (FAK) and AKT, increased the accumulation of caveolin 1 (Cav1), and reduced the activity of extracellular regulated protein kinases (ERK). The inhibition of AKT (GDC-0068) or FAK (PF-573228) not only rescued ERK activity but also prevented AQP1 induction, whereas Au-NP-mediated Cav1 accumulation remained unaltered. Neither these signaling molecules nor AQP1 expression responded to Au-NPs while Cav1 was silenced. Inhibition of ERK activity (U0126) remarkably enhanced Cav1 and AQP1 expression in bEnd.3 cells. These data demonstrate that Au-NP-mediated AQP1 induction is Cav1 dependent, but requires the repression on ERK activity. Mice receiving intranasally administered Au-NPs displayed cerebral edema, significantly augmented AQP1 protein levels; furthermore, mild focal lesions were observed in the cerebral parenchyma. CONCLUSIONS: These data suggest that the subacute exposure of nanoparticles might induce cerebral edema, involving the Cav1 dependent accumulation on endothelial AQP1.

Thermally stable and uniform DNA amplification with picosecond laser ablated graphene rapid thermal cycling device.

Rapid thermal cycling (RTC) in an on-chip device can perform DNA amplification in vitro through precise thermal control at each step of the polymerase chain reaction (PCR). This study reports a straightforward fabrication technique for patterning an on-chip graphene-based device with hole arrays, in which the mechanism of surface structures can achieve stable and uniform thermal control for the amplification of DNA fragments. A thin-film based PCR device was fabricated using picosecond laser (PS-laser) ablation of the multilayer graphene (MLG). Under the optimal fluence of 4.72 J/cm2 with a pulse overlap of 66%, the MLG can be patterned with arrays of 250 µm2 hole surface structures. A 354-bp DNA fragment of VP1, an effective marker for diagnosing the BK virus, was amplified on an on-chip device in less than 60 min. A thin-film electrode with the aforementioned MLG as the heater was demonstrated to significantly enhance temperature stability for each stage of the thermal cycle. The temperature control of the heater was performed by means of a developed programmable PCR apparatus. Our results demonstrated that the proposed integration of a graphene-based device and a laser-pulse ablation process to form a thin-film PCR device has cost benefits in a small-volume reagent and holds great promise for practical medical use of DNA amplification.