Inhibition of DAPK3 Suppresses Radiation-Induced Cellular Senescence by Activation of a PGC1α-Dependent Metabolism Pathway in Brain Endothelial Cells.

In the brain, environmental changes, such as neuroinflammation, can induce senescence, characterized by the decreased proliferation of neurons and dendrites and synaptic and vascular damage, resulting in cognitive decline. Senescence promotes neuroinflammatory disorders by senescence-associated secretory phenotypes and reactive oxygen species. In human brain microvascular endothelial cells (HBMVECs), we demonstrate that chronological aging and irradiation increase death-associated protein kinase 3 (DAPK3) expression. To confirm the role of DAPK3 in HBMVEC senescence, we disrupted DAPK3 activity using small interfering RNA (siRNA) or a dominant-negative mutant (DAPK3-P216S), which reduced cellular senescence phenotypes, as assessed by changes in tube formation, senescence-associated beta-galactosidase activity, and cell proliferation. In endothelial cells, DAPK3 promotes cellular senescence by regulating the phosphorylation and inactivation of peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC1α) via the protein kinase B pathway, resulting in the decreased expression of mitochondrial metabolism-associated genes, such as ATP5G1, BDNF, and COX5A. Our studies show that DAPK3 is involved in cellular senescence and PGC1α regulation, suggesting that DAPK3 regulation may be important for treating aging-related brain diseases or the response to radiation therapy.

Neuromedin U contributes to radiation resistance in colorectal cancer via YAP/TAZ signaling activation.

Resistance to radiation therapy remains a treatment obstacle for patients with high­risk colorectal cancer. Neuromedin U (NMU) has been identified as a potential predictor of the response to radiation therapy by RNA sequencing analysis of colorectal cancer tissues obtained from patients. However, the role of NMU in colorectal cancer remains unknown. In order to investigate role of NMU in colorectal cancer, NMU expression was regulated using small interfering RNA or an NMU­expression pCMV3 vector, and cell counting, wound­healing and clonogenic assays were subsequently performed. NMU knockdown decreased colorectal cancer cell proliferation and migration, and sensitized the cells to radiation. Conversely, NMU overexpression increased radiation resistance, proliferation and migration of colorectal cancer cells. Furthermore, by western blotting and nuclear fractionation experiments, NMU knockdown inhibited the nuclear translocation of yes­associated protein (YAP) and transcriptional co­activator with PDZ­binding motif (TAZ), resulting from the phosphorylation of these proteins. By contrast, the nuclear translocation of YAP and TAZ was increased following NMU overexpression in colorectal cancer cells. Recombinant NMU regulated YAP and TAZ activity, and the expression of the YAP and TAZ transcriptional target genes AXL, connective tissue growth factor and cysteine­rich angiogenic inducer 61 in an NMU receptor 1 activity­dependent manner. These results suggested that NMU may contribute to the acquisition of radioresistance in colorectal cancer by enhancing the Hippo signaling pathway via YAP and TAZ activation.

Association between Serum Folic Acid Levels and Asthma in the Korean Population: A Study Based on the 2016-2018 Korea National Health and Nutrition Examination Survey.

BACKGROUND: Folic acid is involved in inflammatory reactions; however, the association between folic acid and allergic diseases, particularly asthma, remains unclear. Thus, this study aimed to evaluate the association between serum folic acid levels and asthma in Koreans. METHODS: This study analyzed the serum folic acid levels of 6,615 individuals included in the 2016-2018 Korea National Health and Nutrition Examination Survey. The prevalence of asthma was determined using a questionnaire that identified cases of physician-diagnosed asthma. The relationship between serum folic acid levels and asthma was analyzed using logistic regression analysis. RESULTS: Multiple logistic regression analysis showed that a 1 ng/mL increase in serum folic acid level significantly reduced the risk of asthma after adjusting for confounding factors including sex, age, household income, current smoking, current alcohol use, and body mass index (odds ratio [OR], 0.930; 95% confidence interval [CI], 0.876- 0.987; P=0.017). The relationship between the adjusted odds of asthma and serum folic acid levels were consistently inverse (OR, 2.266; 95% CI, 1.126-4.420; P for trend=0.038). CONCLUSION: Serum folic acid levels are inversely associated with physician-diagnosed asthma in the Korean population.

Short Term Isocaloric Ketogenic Diet Modulates NLRP3 Inflammasome Via B-hydroxybutyrate and Fibroblast Growth Factor 21.

A ketogenic diet (KD) is known to have beneficial health effects. Various types of KD interventions have been applied to manage metabolic syndrome based on modification of diet parameters such as duration of intervention, macronutrient components, and total calories. Nevertheless, the beneficial health impact of isocaloric KD is largely unknown, especially in healthy subjects. The present study investigated the acute effects of a 3-day isocaloric KD. In this non-randomized intervention study, we recruited 15 healthy volunteers aged 24-38 years (7 men and 8 women) and placed them on an isocaloric KD restricting intake of carbohydrates but not energy (75% fat, 20% protein, 5% carbohydrate) for 3 days. Biochemical profiles and laboratory measurements were performed. Peripheral blood monocular cells were cultured, and measured cell stimulated cytokines. After short-term isocaloric KD, subjects lost body weight and serum free fatty acid levels were increased. These results accompanied elevated serum ß-hydroxybutyrate (BHB) concentration and fibroblast growth factor 21 (FGF21) levels and improved insulin sensitivity. Regarding the direct effect of BHB on inflammasome activation, interleukin-1ß (IL-1ß) and tumor necrosis factor-α secretion in response to adenosine triphosphate or palmitate stimulation in human macrophages decreased significantly after isocaloric KD. In ex-vivo experiments with macrophages, both FGF21 and BHB further reduced IL-1ß secretion compared to either BHB or FGF21 alone. The inhibitory effect of FGF21 on IL-1ß secretion was blunted with bafilomycin treatment, which blocked autophagy flux. In conclusion, isocaloric KD for 3 days is a promising approach to improve metabolic and inflammatory status. Clinical Trial Registration: clinicaltrials.gov (NCT02964572).

Epigallocatechin Gallate Protects against Hypoxia-Induced Inflammation in Microglia via NF-κB Suppression and Nrf-2/HO-1 Activation.

Hypoxia-induced neuroinflammation in stroke, neonatal hypoxic encephalopathy, and other diseases subsequently contributes to neurological damage and neuronal diseases. Microglia are the primary neuroimmune cells that play a crucial role in cerebral inflammation. Epigallocatechin gallate (EGCG) has a protective antioxidant and anti-inflammatory effects against neuroinflammation. However, the effects of EGCG on hypoxia-induced inflammation in microglia and the underlying mechanism remain unclear. In this study, we investigated whether EGCG might have a protective effect against hypoxia injury in microglia by treatment with CoCl2 to establish a hypoxic model of BV2 microglia cells following EGCG pre-treatment. An exposure of cells to CoCl2 caused an increase in inflammatory mediator interleukin (IL)-6, inducible nitric oxide synthase (iNOS), and cyclooxygenase (COX)-2 expression, which were significantly ameliorated by EGCG via inhibition of NF-κB pathway. In addition, EGCG attenuated the expression of hypoxia-inducible factor (HIF)-1α and the generation of ROS in hypoxic BV2 cells. Furthermore, the suppression of hypoxia-induced IL-6 production by EGCG was mediated via the inhibition of HIF-1α expression and the suppression of ROS generation in BV2 cells. Notably, EGCG increased the Nrf-2 levels and HO-1 levels in the presence of CoCl2. Additionally, EGCG suppressed hypoxia-induced apoptosis of BV2 microglia with cleavage of poly (ADP-ribose) polymerase (PARP) and caspase-3. In summary, EGCG protects microglia from hypoxia-induced inflammation and oxidative stress via abrogating the NF-κB pathway as well as activating the Nrf-2/HO-1 pathway.

Metformin alleviates ionizing radiation-induced senescence by restoring BARD1-mediated DNA repair in human aortic endothelial cells.

Metformin is one of the most effective therapies for treating type 2 diabetes and has been shown to also attenuate aging and age-related disorders. In this study, we explored the relationship between metformin and DNA damage repair in ionizing radiation (IR)-induced damage of human aortic endothelial cells (HAECs). Metformin treatment suppressed IR-induced senescence phenotypes, such as increased senescent-associated ß-galactosidase (SA ß-gal) activity and decreased tube formation and proliferation. Moreover, metformin increased BRCA1-associated RING domain protein 1 (BARD1) and RAD51 expression in both aging and IR-exposed cells. Metformin-treated cells exhibited higher levels of the BRCA1-BARD1-RAD51 complex during irradiation, even in the presence of compound C, an AMP-activated protein kinase inhibitor. BARD1 knockdown confirmed its critical role in metformin-mediated inhibition of endothelial senescence. Metformin increased blood vessel sprouting and decreased SA ß-gal activity in mouse aortas. Collectively, our findings provide new insights into how metformin can prevent endothelial cell senescence by promoting BARD1-related DNA damage repair, suggesting that metformin may be an effective anti-aging agent and a promising therapeutic for protecting against radiation-induced cardiotoxicity.

Radiation-induced lipoprotein-associated phospholipase A2 increases lysophosphatidylcholine and induces endothelial cell damage.

The cardiotoxicity of various anticancer therapies, including radiotherapy, can lead to cardiovascular complications. These complications can range from damaging cardiac tissues within the irradiation field to increasing the long-term risks of developing heart failure, coronary artery disease, and myocardial infarction. We analyzed radiation-induced metabolites capable of mediating critical biological processes, such as inflammation, senescence, and apoptosis. Previously, by applying QTOF-MASS analysis to irradiated human fibroblasts, we identified that metabolite sets of lysophosphatidylcholine (LPC) were increased in these cells. In this study, radiation-induced LPC accumulation in human aortic endothelial cells (HAECs) increased reactive oxygen species (ROS) production and senescence-associated-beta-galactosidase staining, in addition to decreasing their tube-forming ability. Knockdown of lipoprotein-associated phospholipase A2 (Lp-PLA2) with small interfering RNA (siRNA) inhibited the increased LPC production induced by radiation, and reduced the radiation-induced cell damage produced by ROS and oxidized low-density lipoprotein (LDL). Lp-PLA2 depletion abolished the induction of proinflammatory factors, such as interleukin 1ß, tumor necrosis factor-alpha, matrix metalloproteinase 2, and matrix metalloproteinase 9, as well as adhesion molecules, such as intercellular adhesion molecule 1 (ICAM-1) and E-selection. Likewise, we showed that Lp-PLA2 expression was upregulated in the vasculature of irradiated rat, resulting in increased LPC production and LDL oxidation. Our data demonstrate that radiation-induced LPC production is a potential risk factor for cardiotoxicity that is mediated by Lp-PLA2 activity, suggesting that LPC and Lp-PLA2 offer potential diagnostic and therapeutic approaches to cardiovascular damage during radiotherapy.

Cyclooxygenase-2 induces neoplastic transformation by inhibiting p53-dependent oncogene-induced senescence.

Much in vivo evidence indicates that cyclooxygenase-2 (COX-2) is deeply involved in tumorigenesis. Although it has been proposed that COX-2-derived pro-inflammatory prostanoids mediate the tumorigenic activity of COX-2, the tumorigenic mechanisms of COX-2 are not yet fully understood. Here, we investigated the mechanism by which COX-2 causes transformation from normal cells to malignant cells by using normal murine or human cells. We found that COX-2 inhibits the pro-senescent function of p53 under oncogenic RAS activation, by which it prevents oncogene-induced senescence (OIS) and induces neoplastic transformation. We also found that COX-2 physically interacts with p53 in the nucleus under oncogenic RAS activation, and that this COX-2-p53 interaction rather than the catalytic activity is involved in the COX-2-mediated inhibition of the pro-senescent function of p53 and OIS, and induction of neoplastic transformation. These findings strongly suggest that the oncogenic property of COX-2 is closely related to its ability to inactivate p53 under strong mitogenic signals, and that aberrant activation of the COX-2/a mitogenic oncogene combination can be a potent driving force for tumorigenesis. This study might contribute to our understanding of the molecular basis for the tumorigenic activity of COX-2 and the development of novel anti-tumor drugs targeting COX-2-p53 interactions.

Role of Ischemic Preconditioning in the Cardioprotective Mechanisms of Monomeric C-Reactive Protein-Deposited Myocardium in a Rat Model.

BACKGROUND: The deposition of monomeric C-reactive protein (mCRP) in the myocardium aggravates ischemia-reperfusion injury (IRI) and myocardial infarction. Ischemic preconditioning (IPC) is known to protect the myocardium against IRI. METHODS: We evaluated the effects of IPC on myocardium upon which mCRP had been deposited due to IRI in a rat model. Myocardial IRI was induced via ligation of the coronary artery. Direct IPC was applied prior to IRI using multiple short direct occlusions of the coronary artery. CRP was infused intravenously after IRI. The study included sham (n=3), IRI-only (n=5), IRI+CRP (n=9), and IPC+IRI+CRP (n=6) groups. The infarcted area and the area at risk were assessed using Evans blue and 2,3,5-triphenyltetrazolium staining. Additionally, mCRP immunostaining and interleukin-6 (IL-6) mRNA reverse transcription-polymerase chain reaction were performed. RESULTS: In the IRI+CRP group, the infarcted area and the area of mCRP deposition were greater, and the level of IL-6 mRNA expression was higher, than in the IRI-only group. However, in the IPC+IRI+CRP group relative to the IRI+CRP group, the relative areas of infarction (20% vs. 34%, respectively; p=0.079) and mCRP myocardial deposition (21% vs. 44%, respectively; p=0.026) were lower and IL-6 mRNA expression was higher (fold change: 407 vs. 326, respectively; p=0.376), although the difference in IL-6 mRNA expression was not statistically significant. CONCLUSION: IPC was associated with significantly decreased deposition of mCRP and with increased expression of IL-6 in myocardium damaged by IRI. The net cardioprotective effect of decreased mCRP deposition and increased IL-6 levels should be clarified in a further study.

P2Y2R contributes to the development of diabetic nephropathy by inhibiting autophagy response.

OBJECTIVE: Diabetic nephropathy (DN) is one of the most common complications of diabetes and a critical risk factor for developing end-stage renal disease. Activation of purinergic receptors, including P2Y2R has been associated with the pathogenesis of renal diseases, such as polycystic kidney and glomerulonephritis. However, the role of P2Y2R and its precise mechanisms in DN remain unknown. We hypothesised that P2Y2R deficiency may play a protective role in DN by modulating the autophagy signalling pathway. METHODS: We used a mouse model of DN by combining a treatment of high-fat diet and streptozotocin after unilateral nephrectomy in wild-type or P2Y2R knockout mice. We measured renal functional parameter in plasma, examined renal histology, and analysed expression of autophagy regulatory proteins. RESULTS: Hyperglycaemia and ATP release were induced in wild type-DN mice and positively correlated with renal dysfunction. Conversely, P2Y2R knockout markedly attenuates albuminuria, podocyte loss, development of glomerulopathy, renal tubular injury, apoptosis and interstitial fibrosis induced by DN. These protective effects were associated with inhibition of AKT-mediated FOXO3a (forkhead box O3a) phosphorylation and induction of FOXO3a-induced autophagy gene transcription. Furthermore, inhibitory phosphorylation of ULK-1 was decreased, and the downstream Beclin-1 autophagy signalling was activated in P2Y2R deficiency. Increased SIRT-1 (sirtuin-1) and FOXO3a expression in P2Y2R deficiency also enhanced autophagy response, thereby ameliorating renal dysfunction in DN. CONCLUSIONS: P2Y2R contributes to the pathogenesis of DN by impairing autophagy and serves as a therapeutic target for treating DN.

Platycodon grandiflorus Fermented Extracts Attenuate Endotoxin-Induced Acute Liver Injury in Mice.

Endotoxin-induced acute liver injury is mediated by an excessive inflammatory response, hepatocellular oxidative stress, and apoptosis. Traditional medicinal plants have been used to treat various disorders. Platycodon grandifloras (PG) has been shown to be beneficial in relieving cough and asthma and to have anti-tumor, anti-inflammatory, anti-diabetic activities. The pharmacological action of PG is mainly due to saponins, flavonoids, phenolic, and other compounds. However, raw PG exhibits some side effects at high doses. Here, we extracted raw PG with varying fermentation methods and examined its anti-inflammatory effect and associated signaling kinases in Raw264.7 cells. Then, we investigated the effect of fermented black PG (FBPG) on endotoxin-induced liver injury. Mice were administered FBPG orally at 1 h before the lipopolysaccharide and D-galactosamine (LPS/GalN) injection and sacrificed after 5 h. Black PG (BPG) and FBPG showed a significant reduction in pro-inflammatory cytokines and extracellular nitric oxide (NO); p-38 and ERK signaling was involved in reducing inducible NO synthase in Raw264.7 cells. Consistently, FBPG attenuates LPS/GalN-induced liver injury; plasma ALT and AST, hepatic necrosis, pro-inflammatory cytokines, apoptosis, and lipid peroxidation were all reduced. In conclusion, PG extracts, particularly FBPG, play anti-inflammatory, antioxidant, and anti-apoptotic roles, alleviating endotoxin-induced acute liver injury. Processing raw PG into FBPG extract may be clinically useful by improving the pharmacologically active ingredients and reducing the required dosage.

SGLT2 inhibition modulates NLRP3 inflammasome activity via ketones and insulin in diabetes with cardiovascular disease.

Sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce cardiovascular events in humans with type 2 diabetes (T2D); however, the underlying mechanism remains unclear. Activation of the NLR family, pyrin domain-containing 3 (NLRP3) inflammasome and subsequent interleukin (IL)-1ß release induces atherosclerosis and heart failure. Here we show the effect of SGLT2 inhibitor empagliflozin on NLRP3 inflammasome activity. Patients with T2D and high cardiovascular risk receive SGLT2 inhibitor or sulfonylurea for 30 days, with NLRP3 inflammasome activation analyzed in macrophages. While the SGLT2 inhibitor's glucose-lowering capacity is similar to sulfonylurea, it shows a greater reduction in IL-1ß secretion compared to sulfonylurea accompanied by increased serum ß-hydroxybutyrate (BHB) and decreased serum insulin. Ex vivo experiments with macrophages verify the inhibitory effects of high BHB and low insulin levels on NLRP3 inflammasome activation. In conclusion, SGLT2 inhibitor attenuates NLRP3 inflammasome activation, which might help to explain its cardioprotective effects.

Quercetin Inhibits Cell Survival and Metastatic Ability via the EMT-mediated Pathway in Oral Squamous Cell Carcinoma.

This study aimed to investigate whether quercetin exerts anticancer effects on oral squamous cell carcinoma (OSCC) cell lines and to elucidate its mechanism of action. These anticancer effects in OSCC cells were assessed using an MTT assay, flow cytometry (to assess the cell cycle), wound-healing assay, invasion assay, Western blot analysis, gelatin zymography, and immunofluorescence. To investigate whether quercetin also inhibits transforming growth factor ß1 (TGF-ß1)-induced epithelial-mesenchymal transition (EMT) in human keratinocyte cells, HaCaT cells were treated with TGF-ß1. Overall, our results strongly suggest that quercetin suppressed the viability of OSCC cells by inducing cell cycle arrest at the G2/M phase. However, quercetin did not affect cell viability of human keratinocytes such as HaCaT (immortal keratinocyte) and nHOK (primary normal human oral keratinocyte) cells. Additionally, quercetin suppresses cell migration through EMT and matrix metalloproteinase (MMP) in OSCC cells and decreases TGF-ß1-induced EMT in HaCaT cells. In conclusion, this study is the first, to our knowledge, to demonstrate that quercetin can inhibit the survival and metastatic ability of OSCC cells via the EMT-mediated pathway, specifically Slug. Quercetin may thus provide a novel pharmacological approach for the treatment of OSCCs.

Nobiletin ameliorates hepatic ischemia and reperfusion injury through the activation of SIRT-1/FOXO3a-mediated autophagy and mitochondrial biogenesis.

Hepatic ischemia and reperfusion injury are characterized by impaired autophagy, mitochondrial dysfunction, and subsequent compromise of cellular homeostasis following hepatic surgery or transplantation. Nobiletin, a natural flavonoid, is a beneficial antioxidant that possesses anti-inflammatory and anti-cancer activities. We investigated the effect of nobiletin on hepatic IR injury and described the underlying mechanisms. C57BL/6 mice were subjected to 60 min of partial hepatic ischemia, treated with nobiletin (5 mg/kg) or vehicle at the start of reperfusion, and killed at 5 h of reperfusion. Hepatic ischemia and reperfusion increased hepatocellular oxidative damage, inflammation, and cell death, but these changes were alleviated upon nobiletin treatment. Nobiletin increased the expression of proteins that control autophagy, mitochondrial dynamics, and biogenesis. Specifically, the SIRT-1/FOXO3a and PGC-1α pathways were activated by nobiletin. IR-induced AKT activation was associated with FOXO3a phosphorylation, which resulted in a significant reduction in the nuclear FOXO3a levels and potentially attenuated autophagy-regulatory gene expression. Nobiletin increased FOXO3a expression and its nuclear translocation via the inhibition of AKT. Specific inhibition of SIRT-1 abolished the protective effect of nobiletin, causing decreased FOXO3a expression, followed by autophagy induction and decreased PGC-1α expression and mitochondrial dynamics. Taken together, our data indicate that SIRT-1 directly mediates the protective effect of nobiletin against hepatic ischemia and reperfusion injury. The activation of autophagy and mitochondrial function through the SIRT-1/FOXO3a and PGC-1α pathways indicate that nobiletin could have therapeutic potential for treating hepatic ischemia and reperfusion injury.

Perilla Oil Decreases Aortic and Hepatic Lipid Accumulation by Modulating Lipogenesis and Lipolysis in High-Fat Diet-Fed Mice.

Perilla oil has been shown to be beneficial for ameliorating metabolic disorders, but its protective effect is still controversial. We investigated the effect of perilla oil on obesity-induced hepatic and vascular changes in high-fat diet (HFD)-fed mice and provided underlying mechanisms for potential therapeutic applications. Tomato and paprika extract was added to prevent the oxidation during storage of perilla oil. HFD-fed mice were orally administered palm or perilla oil for 90 days. Food intake, body and liver weight, and serum cholesterol levels were measured. Arterial and hepatic lipid accumulation was determined by histological staining. Hepatic triglyceride levels and the expression of proteins regulating lipid metabolism were analyzed. Food intake and body weight were not different between palm oil-treated and perilla oil-treated mice. Serum cholesterol level was significantly lower in perilla oil-treated mice compared with palm oil-treated mice. HFD-induced lipid accumulation was also lower in thoracic aorta and liver by perilla oil compared with palm oil. Perilla oil also decreased hepatic triglyceride level without changing the liver weight. Perilla oil treatment increased the AMP-activated protein kinase and acetyl-CoA carboxylase phosphorylation and the lipolytic protein levels, whereas it decreased the lipogenic protein levels in the liver. In conclusion, perilla oil reduced serum cholesterol and arterial and hepatic lipid accumulation in HFD-fed mice. The data suggest that perilla oil improves the balance of lipogenic and lipolytic protein expression, and ameliorates obesity-induced metabolic disorders and cardiovascular diseases.

The proximal tubular α7 nicotinic acetylcholine receptor attenuates ischemic acute kidney injury through Akt/PKC signaling-mediated HO-1 induction.

Activation of the α7 nicotinic acetylcholine receptor (α7nAChR) has been shown to attenuate excessive inflammation by inhibiting proinflammatory cytokines during ischemia-reperfusion (IR) injury; however, the underlying kidney-specific molecular mechanisms remain unclear. The protective action of α7nAChR against renal IR injury was investigated using a selective α7nAChR agonist and antagonist. α7nAChR activation reduced plasma creatinine levels and tubular cell damage, whereas α7nAChR inhibition aggravated the IR-induced phenotype. α7nAChR activation decreased neutrophil infiltration and proinflammatory cytokine expression, increased heme oxygenase-1 (HO-1) expression, and reduced proximal tubular apoptosis after IR as shown by terminal deoxynucleotidyl transferase dUTP nick-end labeling staining and caspase-3 cleavage. In this study, we first showed that α7nAChR activation in the proximal tubules induced HO-1 expression through the phosphoinositide 3-kinase (PI3K)/Akt and protein kinase C (PKC) signaling pathway in vivo in renal IR mice and in vitro in proximal tubular cells. Chemical inhibitors of PKC or PI3K/Akt and small interfering RNA-mediated PKC silencing confirmed the signal specificity of α7nAChR-mediated HO-1 induction in the proximal tubular cells. α7nAChR activation inhibited high-mobility group box 1 release by inducing HO-1 expression and reduced proinflammatory cytokine gene expression and apoptotic cell death in tumor necrosis factor α-stimulated proximal tubular cells. Taken together, we conclude that α7nAChR activation in proximal tubular cells directly protects cells against renal IR injury by inducing HO-1 expression through PI3K/Akt and PKC signaling.

Feasibility study on the use of gold nanoparticles in fractionated kilovoltage X-ray treatment of melanoma.

PURPOSE: Despite the high radioresistance of melanoma, unresectable lesions can be subjected to radiation treatment with the use of gold nanoparticles (AuNPs) as a dose-enhancing agent preferentially loaded on these lesions. The modality of single high-dose treatment has been investigated to confirm its therapeutic efficiency for AuNP-treated melanoma cells. This study explores the feasibility of utilizing AuNPs in fractionated radiation therapy of melanoma for further therapeutic gain. MATERIALS AND METHODS: The responses of human skin melanoma cells to 150-kVp X-ray exposure at 2 and 4 Gy were assessed by quantify gamma-H2AX expression and clonogenic survival, with or without 320 µM of 50 nm AuNP treatment in a culture medium. The influence of AuNPs on cell cycle distribution was observed before irradiation and during 3 d period after irradiation. RESULTS: The AuNP treatment of melanoma cells influenced the cellular response to kilovoltage X-rays to similar extents in terms of the percentage of gamma-H2AX-positive cells and the fractional loss of clonogenicity. Without radiation exposure, AuNPs reduced the portion of melanoma cells at the G2/M phase from 11 to 7%. After irradiation, the progression of the melanoma cells treated with AuNPs toward the G2/M phase was more rapid than that of the AuNP-free cells, and the release of the former from the G2/M phase was slower than that of the latter. At 24 h after irradiation with AuNPs, the cell cycle was rearranged in a pattern that increased the vulnerability of the cells to radiation damage. CONCLUSIONS: In addition to the benefit of AuNP treatment to the control of melanoma in single high-dose treatment, further therapeutic gain is expected through fractionated X-ray treatment that involves daily exposure. The AuNP-treated melanoma cells of an increased portion in the radiosensitive G2/M phase following a fractionated dose delivery would respond to the next treatment with an enhanced chance of clonogenic death.

Corn silk extract improves benign prostatic hyperplasia in experimental rat model.

BACKGROUND/OBJECTIVES: This study was conducted to investigate the effect of a corn silk extract on improving benign prostatic hyperplasia (BPH). MATERIALS/METHODS: The experimental animals, 6-week-old male Wistar rats, were divided into sham-operated control (Sham) and experimental groups. The experimental group, which underwent orchiectomy and received subcutaneous injection of 10 mg/kg of testosterone propionate to induce BPH, was divided into a Testo Only group that received only testosterone, a Testo+Fina group that received testosterone and 5 mg/kg finasteride, a Testo+CSE10 group that received testosterone and 10 mg/kg of corn silk extract, and a Testo+CSE100 group that received testosterone and 100 mg/kg of corn silk extract. Prostate weight and concentrations of dihydrotestosterone (DHT), 5α-reductase 2 (5α-R2), and prostate specific antigen (PSA) in serum or prostate tissue were determined. The mRNA expressions of 5α-R2 and proliferating cell nuclear antigen (PCNA) in prostate tissue were also measured. RESULTS: Compared to the Sham group, prostate weight was significantly higher in the Testo Only group and decreased significantly in the Testo+Fina, Testo+CSE10, and Testo+CSE100 groups (P < 0.05), results that were consistent with those for serum DHT concentrations. The concentrations of 5α-R2 in serum and prostate as well as the mRNA expression of 5α-R2 in prostate were significantly lower in the Testo+Fina, Testo+CSE10, and Testo+CSE100 groups than that in the Testo Only group (P < 0.05). Similarly, the concentrations of PSA in serum and prostate were significantly lower in the Testo+Fina, Testo+CSE10, and Testo+CSE100 groups (P < 0.05) than in the Testo Only group. The mRNA expression of PCNA in prostate dose-independently decreased in the Testo+CSE-treated groups (P < 0.05). CONCLUSIONS: BPH was induced through injection of testosterone, and corn silk extract treatment improved BPH symptoms by inhibiting the mRNA expression of 5α-R2 and decreasing the amount of 5α-R2, DHT, and PSA in serum and prostate tissue.

Anti-apoptotic effects of Curcuma longa L. extract and its curcuminoids against blue light-induced cytotoxicity in A2E-laden human retinal pigment epithelial cells.

OBJECTIVES: The purpose of the study was to investigate the protective effect of the Curcuma longa L. extract (CLE) and its curcuminoids against blue light-induced cytotoxicity in human retinal pigment epithelial (RPE) cells laded with A2E. A2E has been concerned in age-related macular degeneration (AMD). METHODS: To perform this study, A2E-accumulated ARPE-19 cells were exposed to blue light to induce cytotoxicity. The cytotoxicity and apoptotic gene expression levels were evaluated using a lactate dehydrogenase (LDH) assay and real-time PCR analysis, respectively. KEY FINDINGS: Curcuma longa L. extract was found to exert a protective effect in a dose-dependent manner. At a concentration of 15 µm, curcumin, demethoxycurcumin and bisdemethoxycurcumin exerted significant protective effects against blue light-induced cytotoxicity. Treatment with CLE and curcuminoids meaningfully reduced the mRNA levels of c-Abl and p53, which was known to be augmented in apoptotic RPE cells. Demethoxycurcumin and bisdemethoxycurcumin were found to inhibit p38 expression, which is increased in blue light-irradiated A2E-accumulated RPE cells. CONCLUSIONS: Curcuma longa L. extract and its curcuminoids provided significant protection against photooxidative damage and apoptosis in the RPE cells. Our results suggest that curcuminoids may show potential in the treatment of AMD.

Gold nanoparticles as dose-enhancement agent for kilovoltage X-ray therapy of melanoma.

PURPOSE: Melanoma is mainly treated by surgery and rarely with radiation because of the high radioresistance of this tumor. Nevertheless, radiotherapy is the preferred treatment modality for unresectable lesions and avoiding cosmetic disfigurement caused by surgical excision. This study investigated the therapeutic advantage of gold nanoparticles (AuNPs) for kilovoltage X-ray treatment of melanoma. MATERIALS AND METHODS: Commercial AuNPs were evaluated for cytotoxicity and cellular internalization. The sensitivity of human skin melanoma cells to 150 and 450 kVp X-ray exposure was assessed in terms of clonogenicity with or without spherical AuNP treatment. RESULTS: AuNP treatment elicited dose enhancement effect on melanoma cells exposed to kilovoltage X-rays. Treatment with 320 µM 50 nm AuNPs before exposure to 150 kVp X-rays at 2 Gy resulted in clonogenic cell death equivalent to that caused by 4.3 Gy X-rays without AuNP treatment. CONCLUSION: AuNPs of 50 nm in size can regulate melanoma cells in kilovoltage X-ray treatment by functioning as dose-enhancement agent and thus improving radioresponse of the cells. Melanomas of stages T1-T3 gain therapeutic benefits from 150 kVp X-ray treatment.