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1.
Carbohydr Polym ; 345: 122546, 2024 Dec 01.
Article in English | MEDLINE | ID: mdl-39227091

ABSTRACT

Herein, dexamethasone (DEX) nanocrystalline suspension (NS)-embedded hydrogel (NS-G) was constructed using a hydroxypropyl methylcellulose (HPMC) polymer to enhance cochlear delivery and attenuate hearing loss following intratympanic (IT) injection. Hydrophobic steroidal nanocrystals were prepared using a bead milling technique and incorporated into a polysaccharide hydrogel. The NS-G system with HPMC (average molecular weight, 86,000 g/mol; 15 mg/mL) was characterized as follows: rod-shaped drug crystalline; particle size <300 nm; and constant complex viscosity ≤1.17 Pa·s. Pulverization of the drug particles into submicron diameters enhanced drug dissolution, while the HPMC matrix increased the residence time in the middle ear cavity, exhibiting a controlled release profile. The IT NS-G system elicited markedly enhanced and prolonged drug delivery (> 9 h) to the cochlear tissue compared with that of DEX sodium phosphate (DEX-SP), a water-soluble prodrug. In mice with kanamycin- and furosemide-induced ototoxicity, NS-G markedly enhanced hearing preservation across all frequencies (8-32 kHz), as revealed by an auditory brainstem response test, compared with both saline and DEX-SP. Moreover, treatment with NS-G showed enhanced anti-inflammatory effects, as evidenced by decreased levels of inflammation-related cytokines. Therefore, the IT administration of DEX NS-loaded HPMC hydrogels is a promising strategy for treating hearing loss.


Subject(s)
Cochlea , Dexamethasone , Hearing Loss , Hydrogels , Hypromellose Derivatives , Injection, Intratympanic , Nanoparticles , Dexamethasone/chemistry , Dexamethasone/administration & dosage , Animals , Hypromellose Derivatives/chemistry , Hydrogels/chemistry , Nanoparticles/chemistry , Mice , Cochlea/drug effects , Cochlea/pathology , Hearing Loss/drug therapy , Hearing Loss/chemically induced , Drug Liberation , Male , Drug Delivery Systems/methods
2.
Sci Rep ; 14(1): 11167, 2024 05 15.
Article in English | MEDLINE | ID: mdl-38750091

ABSTRACT

Xanthine oxidoreductase (XOR) contributes to reactive oxygen species production. We investigated the cytoprotective mechanisms of XOR inhibition against high glucose (HG)-induced glomerular endothelial injury, which involves activation of the AMP-activated protein kinase (AMPK). Human glomerular endothelial cells (GECs) exposed to HG were subjected to febuxostat treatment for 48 h and the expressions of AMPK and its associated signaling pathways were evaluated. HG-treated GECs were increased xanthine oxidase/xanthine dehydrogenase levels and decreased intracellular AMP/ATP ratio, and these effects were reversed by febuxostat treatment. Febuxostat enhanced the phosphorylation of AMPK, the activation of peroxisome proliferator-activated receptor (PPAR)-gamma coactivator (PGC)-1α and PPAR-α and suppressed the phosphorylation of forkhead box O (FoxO)3a in HG-treated GECs. Febuxostat also decreased nicotinamide adenine dinucleotide phosphate oxidase (Nox)1, Nox2, and Nox4 expressions; enhanced superoxide dismutase activity; and decreased malondialdehyde levels in HG-treated GECs. The knockdown of AMPK inhibited PGC-1α-FoxO3a signaling and negated the antioxidant effects of febuxostat in HG-treated GECs. Despite febuxostat administration, the knockdown of hypoxanthine phosphoribosyl transferase 1 (HPRT1) also inhibited AMPK-PGC-1α-FoxO3a in HG-treated GECs. XOR inhibition alleviates oxidative stress by activating AMPK-PGC-1α-FoxO3a signaling through the HPRT1-dependent purine salvage pathway in GECs exposed to HG conditions.


Subject(s)
AMP-Activated Protein Kinases , Acute Kidney Injury , Endothelial Cells , Glucose , Purines , Xanthine Dehydrogenase , Humans , AMP-Activated Protein Kinases/drug effects , AMP-Activated Protein Kinases/metabolism , Endothelial Cells/metabolism , Endothelial Cells/drug effects , Febuxostat/pharmacology , Glucose/metabolism , Kidney Glomerulus/metabolism , Kidney Glomerulus/pathology , Kidney Glomerulus/drug effects , Oxidative Stress/drug effects , Purines/pharmacology , Reactive Oxygen Species/metabolism , Signal Transduction/drug effects , Xanthine Dehydrogenase/antagonists & inhibitors , Xanthine Dehydrogenase/metabolism , Acute Kidney Injury/chemically induced , Acute Kidney Injury/metabolism
3.
Int J Mol Sci ; 24(4)2023 Feb 14.
Article in English | MEDLINE | ID: mdl-36835220

ABSTRACT

Xanthine oxidase (XO) is an important source of reactive oxygen species. This study investigated whether XO inhibition exerts renoprotective effects by inhibiting vascular endothelial growth factor (VEGF) and NADPH oxidase (NOX) in diabetic kidney disease (DKD). Febuxostat (5 mg/kg) was administered to streptozotocin (STZ)-treated 8-week-old male C57BL/6 mice via intraperitoneal injection for 8 weeks. The cytoprotective effects, its mechanism of XO inhibition, and usage of high-glucose (HG)-treated cultured human glomerular endothelial cells (GECs) were also investigated. Serum cystatin C, urine albumin/creatinine ratio, and mesangial area expansion were significantly improved in febuxostat-treated DKD mice. Febuxostat reduced serum uric acid, kidney XO levels, and xanthine dehydrogenase levels. Febuxostat suppressed the expression of VEGF mRNA, VEGF receptor (VEGFR)1 and VEGFR3, NOX1, NOX2, and NOX4, and mRNA levels of their catalytic subunits. Febuxostat caused downregulation of Akt phosphorylation, followed by the enhancement of dephosphorylation of transcription factor forkhead box O3a (FoxO3a) and the activation of endothelial nitric oxide synthase (eNOS). In an in vitro study, the antioxidant effects of febuxostat were abolished by a blockade of VEGFR1 or VEGFR3 via NOX-FoxO3a-eNOS signaling in HG-treated cultured human GECs. XO inhibition attenuated DKD by ameliorating oxidative stress through the inhibition of the VEGF/VEGFR axis. This was associated with NOX-FoxO3a-eNOS signaling.


Subject(s)
Diabetic Nephropathies , Xanthine Oxidase , Animals , Humans , Male , Mice , Diabetic Nephropathies/drug therapy , Diabetic Nephropathies/enzymology , Endothelial Cells/metabolism , Febuxostat/pharmacology , Mice, Inbred C57BL , NADPH Oxidases/metabolism , Nitric Oxide Synthase Type III/metabolism , Oxidative Stress , RNA, Messenger/metabolism , Signal Transduction , Uric Acid/pharmacology , Vascular Endothelial Growth Factor A/metabolism , Vascular Endothelial Growth Factors/metabolism , Xanthine Oxidase/antagonists & inhibitors
4.
Int J Dermatol ; 60(6): 736-741, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33598934

ABSTRACT

BACKGROUND: EPHB4 and its ligand, ephrin B2, which are receptor tyrosine kinases of the erythropoietin-producing hepatocellular (EPH) family, are known to be linked to several human cancers. The aim of this study was to investigate their expression patterns in cutaneous squamous cell carcinoma (CSCC) in association with tumor differentiation and other variable clinical characteristics. MATERIALS AND METHODS: Immunohistochemical staining for EPHB4 and ephrin B2 was performed in 32 cases of CSCC with different histologic grades. The clinical characteristics and histologic grades of CSCC were evaluated in association with EPHB4 and ephrin B2 expression patterns. RESULTS: EPHB4 and ephrin B2 expression levels were significantly inversely proportional to the grade of differentiation of CSCC (P < 0.001 and P < 0.001, respectively). CONCLUSION: These results indicated that EPHB4 and ephrin B2 can be useful markers for poorly differentiated CSCC.


Subject(s)
Carcinoma, Squamous Cell , Ephrin-B2 , Receptor, EphB4 , Skin Neoplasms , Cell Differentiation , Ephrin-B2/genetics , Humans , Receptor, EphB4/genetics
5.
Nanomedicine ; 32: 102329, 2021 02.
Article in English | MEDLINE | ID: mdl-33181275

ABSTRACT

We used antioxidant-containing nanoparticles (NPs) to treat acute hearing loss. Alpha-lipoic acid (ALA) served as the antioxidant; we employed Pluronic F127 to fabricate NPs. In vitro, ALA-NPs protected cells of the organ of Corti in HEI-OC1 mice, triggering nuclear translocation of NRF2 and increases in the levels of antioxidant proteins, including Nrf2, HO-1, SOD-1, and SOD-2. In vivo, the hearing of mice that received ALA-NP injections into the middle ear cavity was better preserved after induction of ototoxicity than in control animals. The cochlear Nrf2 level increased in test mice, indicating that the ALA-NPs protected hearing via the antioxidant mechanism observed in vitro. ALA-NPs effectively protected against acute hearing loss by activating the Nrf2/HO-1 pathway.


Subject(s)
Hearing Loss/drug therapy , Nanoparticles/chemistry , Poloxamer/chemistry , Thioctic Acid/administration & dosage , Thioctic Acid/therapeutic use , Tympanic Membrane/pathology , Animals , Antioxidants/pharmacology , Cell Death/drug effects , Cell Line , Cell Nucleus/drug effects , Cell Nucleus/metabolism , Disease Models, Animal , Hearing Loss/pathology , Male , Mice, Inbred C57BL , NF-E2-Related Factor 2/metabolism , Nanoparticles/ultrastructure , Thioctic Acid/pharmacology
6.
Korean J Intern Med ; 36(3): 596-607, 2021 05.
Article in English | MEDLINE | ID: mdl-31875666

ABSTRACT

BACKGROUND/AIMS: Connective tissue growth factor (CTGF) is a profibrotic factor implicated in pressure overload-mediated myocardial fibrosis. In this study, we determined the role of predicted CTGF-targeting microRNAs (miRNAs) in rat models of aortic stenosis and reverse cardiac remodeling. METHODS: Minimally invasive ascending aortic banding was performed in 24 7-week-old male Sprague-Dawley rats, which were divided into three groups. The banding group consisted of eight rats that were sacrificed immediately after 6 weeks of aortic constriction. The debanding group underwent aortic constriction for 4 weeks and was sacrificed 2 weeks after band removal. The third group underwent sham surgery. We investigated the expression of CTGF, transforming growth factor-ß1 (TGFß1), and matrix metalloproteinase-2 using ELISA and examined miRNA-26b, miRNA-133a, and miRNA-19b as predicted CTGF-targeting miRNAs based on miRNA databases in 24-hour TGFß-stimulated and TGFß- washed fibroblasts and myocardial tissues from all subjects. RESULTS: CTGF was elevated in 24-hour TGFß-stimulated fibroblasts and decreased in 24-hour TGFß-washed fibroblasts. miRNA-26b was significantly increased in TGFß-washed fibroblasts compared with control and TGFß-stimulated fibroblasts (p < 0.05). CTGF expression was significantly higher in the banding group than that in the sham and debanding groups. The relative expression levels of miRNA-26b were higher in the debanding group than in the banding group. CONCLUSION: The results of our study using models of aortic banding and debanding suggested that miRNA-26b was significantly increased after aortic debanding. The in vitro model yielded the same results: miRNA-26b was upregulated after removal of TGFß from fibroblasts.


Subject(s)
Connective Tissue Growth Factor , MicroRNAs/metabolism , Animals , Connective Tissue Growth Factor/genetics , Male , Matrix Metalloproteinase 2 , MicroRNAs/genetics , Myocardium , Rats , Rats, Sprague-Dawley , Transforming Growth Factor beta1
7.
Int J Mol Sci ; 21(10)2020 May 19.
Article in English | MEDLINE | ID: mdl-32438631

ABSTRACT

Cilastatin is a specific inhibitor of renal dehydrodipeptidase-1. We investigated whether cilastatin preconditioning attenuates renal ischemia-reperfusion (IR) injury via hypoxia inducible factor-1α (HIF-1α) activation. Human proximal tubular cell line (HK-2) was exposed to ischemia, and male C57BL/6 mice were subjected to bilateral kidney ischemia and reperfusion. The effects of cilastatin preconditioning were investigated both in vitro and in vivo. In HK-2 cells, cilastatin upregulated HIF-1α expression in a time- and dose-dependent manner. Cilastatin enhanced HIF-1α translation via the phosphorylation of Akt and mTOR was followed by the upregulation of erythropoietin (EPO) and vascular endothelial growth factor (VEGF). Cilastatin did not affect the expressions of PHD and VHL. However, HIF-1α ubiquitination was significantly decreased after cilastatin treatment. Cilastatin prevented the IR-induced cell death. These cilastatin effects were reversed by co-treatment of HIF-1α inhibitor or HIF-1α small interfering RNA. Similarly, HIF-1α expression and its upstream and downstream signaling were significantly enhanced in cilastatin-treated kidney. In mouse kidney with IR injury, cilastatin treatment decreased HIF-1α ubiquitination independent of PHD and VHL expression. Serum creatinine level and tubular necrosis, and apoptosis were reduced in cilastatin-treated kidney with IR injury, and co-treatment of cilastatin with an HIF-1α inhibitor reversed these effects. Thus, cilastatin preconditioning attenuated renal IR injury via HIF-1α activation.


Subject(s)
Cilastatin/pharmacology , Ischemic Preconditioning , Kidney/pathology , Reperfusion Injury/metabolism , Reperfusion Injury/pathology , Animals , Apoptosis/drug effects , Cell Line , Cell Survival/drug effects , Humans , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Indazoles/pharmacology , Male , Mice , Mice, Inbred C57BL , Protective Agents/pharmacology , Proto-Oncogene Proteins c-akt/metabolism , Signal Transduction/drug effects , TOR Serine-Threonine Kinases/metabolism , Ubiquitination/drug effects , Up-Regulation/drug effects
8.
Pancreas ; 49(2): 281-289, 2020 02.
Article in English | MEDLINE | ID: mdl-32011533

ABSTRACT

OBJECTIVE: The aim of this study was to investigate the effects of eupatilin on protein kinase D1 (PKD1) and nuclear factor kappa B (NF-κB) signaling pathways in cerulein-induced in vitro pancreatitis. METHODS: We used collagenase digestion to isolate pancreatic acinar cells from male C57BL/6 mice. In vitro acute pancreatitis was induced by treatment with a supramaximal dose of cerulein. Eupatilin was pretreated before stimulation with cerulein. RESULTS: Eupatilin significantly reduced cerulein-induced amylase release in pancreatic acini. Eupatilin treatment downregulated cerulein-induced expression of interleukin (IL)-1ß, IL-6, and CC chemokine ligands 2 and 5, but it upregulated expression of IL-4 and IL-10. We demonstrated that eupatilin pretreatment attenuated cerulein-induced necrosis in isolated pancreatic acinar cells. This effect of eupatilin was confirmed by lactic dehydrogenase assay, fluorescence-activated cell sorting analysis, and cytopathologic analysis. Eupatilin inhibited cerulein-induced activation of PKD1/NF-κB and the nuclear translocation of NF-κB. CONCLUSIONS: Our data demonstrated that eupatilin is a potential therapeutic candidate for the treatment of pancreatitis through its ability to reduce cellular necrosis and inflammatory responses by inhibition of the PKD1/NF-κB signaling pathway.


Subject(s)
Flavonoids/pharmacology , Pancreatitis/prevention & control , Protein Kinase C/metabolism , Signal Transduction/drug effects , Acinar Cells/drug effects , Acinar Cells/metabolism , Active Transport, Cell Nucleus/drug effects , Acute Disease , Amylases/metabolism , Animals , Cell Nucleus/drug effects , Cell Nucleus/metabolism , Ceruletide , Cytokines/metabolism , Male , Mice, Inbred C57BL , NF-kappa B/metabolism , Pancreatitis/chemically induced , Pancreatitis/metabolism
9.
PLoS One ; 14(12): e0226769, 2019.
Article in English | MEDLINE | ID: mdl-31877176

ABSTRACT

The production of reactive oxygen species (ROS) by cisplatin is one of the major mechanisms of cisplatin-induced cytotoxicity. We examined the preventive effect of α-lipoic acid (LA) on cisplatin-induced toxicity via its antioxidant effects on in vitro and ex vivo culture systems. To elucidate the mechanism of the antioxidant activity of LA, NRF2 was inhibited using NRF2 siRNA, and the change in antioxidant activity of LA was characterized. MTT assays showed that LA was safe at concentrations up to 0.5 mM in HEI-OC1 cells and had a protective effect against cisplatin-induced cytotoxicity. Intracellular ROS production in HEI-OC1 cells was rapidly increased by cisplatin for up to 48 h. However, treatment with LA significantly reduced the production of ROS and increased the expression of the antioxidant proteins HO-1 and SOD1. Ex vivo, the organs of Corti of the group pretreated with LA exhibited better preservation than the group that received cisplatin alone. We also confirmed the nuclear translocation of NRF2 after LA administration, and that NRF2 inhibition decreased the antioxidant activity of LA. Together, these results indicate that the antioxidant activity of LA was through the activation of the NRF2/HO-1 antioxidant pathway.


Subject(s)
Antineoplastic Agents/adverse effects , Antioxidants/pharmacology , Cisplatin/adverse effects , Heme Oxygenase-1/metabolism , NF-E2-Related Factor 2/metabolism , Thioctic Acid/pharmacology , Animals , Cell Line , Cells, Cultured , Mice , Mice, Inbred C57BL , Reactive Oxygen Species/metabolism , Signal Transduction/drug effects
10.
Free Radic Biol Med ; 145: 209-220, 2019 12.
Article in English | MEDLINE | ID: mdl-31560952

ABSTRACT

Reactive oxygen species (ROS) play a pivotal role in the development of contrast-induced nephropathy (CIN). The inhibition of xanthine oxidoreductase is known to reduce levels of ROS. We investigated whether febuxostat could attenuate oxidative stress via the activation of adenosine monophosphate-activated protein kinase (AMPK) against CIN. In a mouse model of CIN, renal impairment and tubular injury substantially increased, whereas febuxostat attenuated renal injury. Plasma and kidney xanthine oxidoreductase levels were decreased by febuxostat. Febuxostat administration was accompanied by the upregulation of AMPK phosphorylation and the inhibition of nicotinamide-adenine dinucleotide phosphate oxidase (Nox)1 and Nox2, followed by the inhibition of hypoxia-inducible factor-1α (HIF-1α) and heme oxygenase-1 expressions and the suppression of transcription factor forkhead box O (FoxO)1 and FoxO3a phosphorylation. Cell survival was significantly reduced after iohexol administration and febuxostat ameliorated iohexol-induced cell death in proximal tubular (HK-2) cells. Furthermore, febuxostat enhanced AMPK phosphorylation and inhibited Nox1, Nox2, and HIF-1α expression in iohexol-exposed HK-2 cells. Finally, these processes decrease ROS in both in vivo and in vitro models of CIN. AMPK inhibition using small interfering RNA blunted the antioxidative effects of febuxostat in iohexol-treated HK-2 cells. Febuxostat attenuated CIN by modulating oxidative stress through AMPK-NADPH oxidase-HIF-1α signaling.


Subject(s)
Acute Kidney Injury/drug therapy , Contrast Media/adverse effects , Hypoxia-Inducible Factor 1, alpha Subunit/genetics , NADPH Oxidase 1/genetics , Protein Kinases/genetics , AMP-Activated Protein Kinase Kinases , Acute Kidney Injury/chemically induced , Acute Kidney Injury/genetics , Acute Kidney Injury/pathology , Animals , Antioxidants/pharmacology , Apoptosis/drug effects , Forkhead Box Protein O1/genetics , Forkhead Box Protein O3/genetics , Gene Expression Regulation/drug effects , Humans , Iohexol/pharmacology , Kidney/drug effects , Kidney/injuries , Kidney Tubules/drug effects , Kidney Tubules/injuries , Kidney Tubules/pathology , Mice , NADPH Oxidase 2/genetics , Oxidative Stress/drug effects , Protein Kinases/drug effects , RNA, Small Interfering/pharmacology , Reactive Oxygen Species/metabolism , Signal Transduction/drug effects
11.
Biomaterials ; 171: 133-143, 2018 07.
Article in English | MEDLINE | ID: mdl-29689410

ABSTRACT

To develop efficient carriers for inner ear drug delivery, we prepared four kinds of phospholipid-based nanoparticles: neutral, anionic, cationic, and cationic-PEG (polyethyleneglycol) particles. PEG was used to maintain long-term particle circulation in the perilymph, avoiding non-specific binding of particles to proteins. All four nanoparticles were about 200 nm in diameter, and their zeta potentials were -4.32, -26.0, +25.8, and -0.28, respectively, for neutral, anionic, cationic, and cationic-PEG nanoparticles. To test particle efficacy in vitro, we used an artificial mucosa 100 µm in thickness to model the round window membrane (RWM) and HEI-OC1 cells, which were treated with particles containing Nile Red dye. Based on the levels of particle penetration and cellular uptake in this model system, we selected an optimal particle for further study. We also observed the movement of particles in ex vivo organotypic cultures of the organ of Corti. In mice, we analyzed the biodistribution of dexamethasone (Dex) in the inner ear after intratympanic injection of Dex-loaded nanoparticles. Then, we tested the therapeutic utility of the Dex-loaded nanoparticles in a mouse model of ototoxicity. In the auditory brainstem response (ABR) test, particle provided improved hearing loss recovery at all tested frequencies, more so than did the Dex sodium phosphate (Dex-SP) solution in current clinical use. Furthermore, quantitative PCR showed that nanoparticles reduced the levels of pro-inflammatory cytokines, exhibiting anti-inflammatory effects superior to those of Dex-SP. Thus, the surface properties of nanoparticles play pivotal roles in particle penetration and distribution after intratympanic injection. Our in vitro screening system using an artificial mucosa will also be valuable in the development of carriers for inner ear drug delivery.


Subject(s)
Drug Delivery Systems , Ear, Inner/pathology , Nanoparticles/chemistry , Phospholipids/chemistry , Animals , Cell Death/drug effects , Cell Line , Dexamethasone/administration & dosage , Dexamethasone/pharmacology , Disease Models, Animal , Drug Carriers/chemistry , Ear, Inner/drug effects , Humans , Male , Mice, Inbred C57BL , Nanoparticles/ultrastructure , Polyethylene Glycols/chemistry
13.
Anticancer Res ; 37(10): 5415-5423, 2017 10.
Article in English | MEDLINE | ID: mdl-28982851

ABSTRACT

Unopposed phosphoinositide 3-kinase (PI3K) activity and 3-phosphoinositide production in Jurkat cells, due to a mutation in the phosphatase and tensin homolog deleted on chromosome 10 (PTEN) tumor-suppressor protein, results in deregulation of PH domain-containing proteins including the serine/threonine kinase PKB. In Jurkat cells, PKB is constitutively active and phosphorylated at the activation-loop residue (Thr308). 3-Phosphoinositide-dependent protein kinase-1 (PDK1), an enzyme that also contains a PH domain, catalyses Thr308 phosphorylation of PKB in addition to other kinase families such as PKC isoforms. It is unknown, however, whether the loss of PTEN in Jurkat cells also results in unregulated PDK1 activity and whether such loss has an impact on activation-loop phosphorylation of other PDK1 substrates e.g. PKC. In this study, we addressed whether loss of PTEN in Jurkat cells affects PDK1 catalytic activity and intracellular localization. We demonstrated that reducing the level of 3-phosphoinositides in Jurkat cells with pharmacological inhibitors of PI3K or expression of PTEN does not affect PDK1 activity or its intracellular localization. We conclude, therefore, that although Jurkat cells lack PTEN expression, only a subset of pathways downstream of PDK1 are perturbed as a consequence of PTEN loss.


Subject(s)
3-Phosphoinositide-Dependent Protein Kinases/metabolism , Leukemia, T-Cell/enzymology , PTEN Phosphohydrolase/metabolism , Phosphatidylinositol 3-Kinase/metabolism , Catalysis , Gene Expression Regulation, Enzymologic , Gene Expression Regulation, Neoplastic , Humans , Jurkat Cells , Leukemia, T-Cell/genetics , Leukemia, T-Cell/pathology , PTEN Phosphohydrolase/genetics , Phosphoinositide-3 Kinase Inhibitors , Phosphorylation , Protein Kinase Inhibitors/pharmacology , Proto-Oncogene Proteins c-akt/metabolism , Signal Transduction , Time Factors , Transfection
15.
Kidney Res Clin Pract ; 36(2): 145-158, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28680822

ABSTRACT

BACKGROUND: Vitamin D is considered to exert a protective effect on various renal diseases but its underlying molecular mechanism remains poorly understood. This study aimed to determine whether paricalcitol attenuates inflammation and apoptosis during lipopolysaccharide (LPS)-induced renal proximal tubular cell injury through the prostaglandin E2 (PGE2) receptor EP4. METHODS: Human renal tubular epithelial (HK-2) cells were pretreated with paricalcitol (2 ng/mL) for 1 hour and exposed to LPS (1 µg/mL). The effects of paricalcitol pretreatment in relation to an EP4 blockade using AH-23848 or EP4 small interfering RNA (siRNA) were investigated. RESULTS: The expression of cyclooxygenase-2, PGE2, and EP4 were significantly increased in LPS-exposed HK-2 cells treated with paricalcitol compared with cells exposed to LPS only. Paricalcitol prevented cell death induced by LPS exposure, and the cotreatment of AH-23848 or EP4 siRNA offset these cell-protective effects. The phosphorylation and nuclear translocation of p65 nuclear factor-kappaB (NF-κB) were decreased and the phosphorylation of Akt was increased in LPS-exposed cells with paricalcitol treatment. AH-23848 or EP4 siRNA inhibited the suppressive effects of paricalcitol on p65 NF-κB nuclear translocation and the activation of Akt. The production of proinflammatory cytokines and the number of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling-positive cells were attenuated by paricalcitol in LPS exposed HK-2 cells. The cotreatment with an EP4 antagonist abolished these anti-inflammatory and antiapoptotic effects. CONCLUSION: EP4 plays a pivotal role in anti-inflammatory and antiapoptotic effects through Akt and NF-κB signaling after paricalcitol pretreatment in LPS-induced renal proximal tubule cell injury.

16.
Oxid Med Cell Longev ; 2017: 5031926, 2017.
Article in English | MEDLINE | ID: mdl-28465762

ABSTRACT

The protective mechanism of paricalcitol remains unclear in renal ischemia-reperfusion (IR) injury. We investigated the renoprotective effects of paricalcitol in IR injury through the prostaglandin E2 (PGE2) receptor EP4. Paricalcitol was injected into IR-exposed HK-2 cells and mice subjected to bilateral kidney ischemia for 23 min and reperfusion for 24 hr. Paricalcitol prevented IR-induced cell death and EP4 antagonist cotreatment offset these protective effects. Paricalcitol increased phosphorylation of Akt and cyclic AMP responsive element binding protein (CREB) and suppressed nuclear factor-κB (NF-κB) in IR-exposed cells and cotreatment of EP4 antagonist or EP4 small interfering RNA blunted these signals. In vivo studies showed that paricalcitol improved renal dysfunction and tubular necrosis after IR injury and cotreatment with EP4 antagonist inhibited the protective effects of paricalcitol. Phosphorylation of Akt was increased and nuclear translocation of p65 NF-κB was decreased in paricalcitol-treated mice with IR injury, which was reversed by EP4 blockade. Paricalcitol decreased oxidative stress and apoptosis in renal IR injury. Paricalcitol also attenuated the infiltration of inflammatory cells and production of proinflammatory cytokines after IR injury. EP4 antagonist abolished these antioxidant, anti-inflammatory, and antiapoptotic effects. The EP4 plays a pivotal role in the protective effects of paricalcitol in renal IR injury.


Subject(s)
Apoptosis/drug effects , Kidney Diseases/prevention & control , Kidney/metabolism , Oxidative Stress/drug effects , Receptors, Prostaglandin E, EP4 Subtype/metabolism , Reperfusion Injury/prevention & control , Second Messenger Systems/drug effects , Animals , Ergocalciferols , Kidney/pathology , Kidney Diseases/metabolism , Kidney Diseases/pathology , Male , Mice , Proto-Oncogene Proteins c-akt/metabolism , Reperfusion Injury/metabolism , Reperfusion Injury/pathology , Transcription Factor RelA/metabolism
17.
Toxicol Lett ; 277: 9-17, 2017 Aug 05.
Article in English | MEDLINE | ID: mdl-28549670

ABSTRACT

BACKGROUND: Oxidative stress is one of the main pathogenic mechanisms in vancomycin-induced nephrotoxicity (VIN). Some studies suggest proximal renal tubular cell necrosis by vancomycin accumulation as a mechanism of nephrotoxicity, and other studies demonstrate that cilastatin has protective effects against drug-induced nephrotoxicity. We investigated whether cilastatin regulates p-gp expression and whether cilastation prevents VIN. MATERIALS AND METHODS: We conducted an in vitro study using an immortalized proximal tubule epithelial cell line from a normal adult human kidney (HK-2) and an in vivo study using male C57BL/6J mice. RESULTS: Vancomycin showed dose-dependent toxicity in the HK-2 cells, and cilastatin attenuated VIN. Vancomycin provoked the reactive oxygen species in a dose-dependent pattern on DCF-DA. Caspase 3/7 activity showed a dose-dependent increase at 6h. We confirmed apoptosis by Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay at 24h (vancomcyin 2mM). Cilastatin attenuated vancomycin-induced ROS production and apoptosis, and it also attenuated vancomycin-induced P-gp suppression. In vivo, vancomycin (400mg/kg, 600mg/kg IP, 7days) induced acute kidney injury, as demonstrated by elevated blood urea nitrogen and creatinine. Histological examination of the sections indicated greater tubular damage in the vancomycin-treated kidney compared with the control. TUNEL-positive cells decreased significantly in the mouse kidney with cilastatin and vancomycin. Bax/Bcl-2 ratio were significantly increased in the vancomycin-treated kidney. Cilastatin 300mg/kg treatment significantly decreased the vancomycin concentrations in the blood and kidney. CONCLUSION: Our study showed that mechanism of VIN might be involved, at least in part, in suppressing P-gp function, and cilastatin attenuated VIN.


Subject(s)
Acute Kidney Injury/prevention & control , Cilastatin/pharmacology , Kidney Tubules, Proximal/drug effects , Protective Agents/pharmacology , Vancomycin/toxicity , ATP Binding Cassette Transporter, Subfamily B/drug effects , ATP Binding Cassette Transporter, Subfamily B/metabolism , Acute Kidney Injury/chemically induced , Acute Kidney Injury/metabolism , Acute Kidney Injury/pathology , Animals , Apoptosis/drug effects , Cell Line , Cell Proliferation/drug effects , Cytoprotection , Dose-Response Relationship, Drug , Humans , Kidney Tubules, Proximal/metabolism , Kidney Tubules, Proximal/pathology , Male , Mice , Mice, Inbred C57BL , Oxidative Stress/drug effects , Reactive Oxygen Species/metabolism , Signal Transduction/drug effects , Time Factors , Vancomycin/metabolism
18.
Lab Invest ; 97(4): 478-489, 2017 04.
Article in English | MEDLINE | ID: mdl-28112758

ABSTRACT

The functional unit of the thyroid gland, the thyroid follicle, dynamically responds to various stimuli to maintain thyroid hormone homeostasis. However, thyroid follicles in the adult human thyroid gland have a very limited regenerative capacity following partial resection of the thyroid gland. To gain insight into follicle regeneration in the adult thyroid gland, we observed the regeneration processes of murine thyroid follicles after partial resection of the lower third of the thyroid gland in 10-week-old male C57BL/6 mice. Based on sequential observation of the partially resected thyroid lobe, we found primitive follicles forming in the area corresponding to the central zone of the intact lateral thyroid lobe. The primitive thyroid follicles were multiciliated and had coarsely vacuolated cytoplasm and large vesicular nuclei. Consistently, these primitive follicular cells did not express the differentiation markers paired box gene-8 and thyroid transcription factor-1 (clone SPT24), but were positive for forkhead box protein A2 and leucine-rich repeat-containing G-protein-coupled receptor 4/GPR48. Follicles newly generated from the primitive follicles had clear or vacuolar cytoplasm with dense, darkly stained nuclei. At day 21 after partial thyroidectomy, the tall cuboidal follicular epithelial cells had clear or vacuolar cytoplasm, and the intraluminal colloid displayed pale staining. Smaller activated follicles were found in the central zone of the lateral lobe, whereas larger mature follicles were located in the peripheral zone. Based on these observations, we propose that the follicle regeneration process in the partially resected adult murine thyroid gland associated with the appearance of primitive follicular cells may be a platform for the budding of differentiated follicles in mice.


Subject(s)
Regeneration , Thyroid Gland/cytology , Thyroid Gland/physiology , Thyroidectomy , Adult , Animals , Cilia/physiology , Epithelial Cells/metabolism , Epithelial Cells/physiology , Hepatocyte Nuclear Factor 3-beta/metabolism , Humans , Immunohistochemistry , Male , Mice, Inbred C57BL , Models, Biological , Receptors, G-Protein-Coupled/metabolism , Thyroid Gland/surgery , Thyroid Hormones/blood , Time Factors
19.
Int J Nanomedicine ; 11: 6123-6134, 2016.
Article in English | MEDLINE | ID: mdl-27895484

ABSTRACT

Dexamethasone (Dex)-loaded PHEA-g-C18-Arg8 (PCA) nanoparticles (PCA/Dex) were developed for the delivery of genes to determine the synergistic effect of Dex on gene expression. The cationic PCA nanoparticles were self-assembled to create cationic micelles containing an octadecylamine (C18) core with Dex and an arginine 8 (Arg8) peptide shell for electrostatic complexation with nucleic acids (connexin 26 [Cx26] siRNA, green fluorescent protein [GFP] DNA or brain-derived neurotrophic factor [BDNF] pDNA). The PCA/Dex nanoparticles conjugated with Arg8, a cell-penetrating peptide that enhances permeability through a round window membrane in the inner ear for gene delivery, exhibited high uptake efficiency in HEI-OC1 cells. This potential carrier co-delivering Dex and the gene into inner ear cells has a diameter of 120-140 nm and a zeta potential of 20-25 mV. Different types of genes were complexed with the Dex-loaded PCA nanoparticle (PCA/Dex/gene) for gene expression to induce additional anti-inflammatory effects. PCA/Dex showed mildly increased expression of GFP and lower mRNA expression of inflammatory cytokines (IL1b, IL12, and INFr) than did Dex-free PCA nanoparticles and Lipofectamine® reagent in HEI-OC1 cells. In addition, after loading Cx26 siRNA onto the surface of PCA/Dex, Cx26 gene expression was downregulated according to real-time polymerase chain reaction for 24 h, compared with that using Lipofectamine reagent. After loading BDNF DNA into PCA/Dex, increased expression of BDNF was observed for 30 h, and its signaling pathway resulted in an increase in phosphorylation of Akt, observed by Western blotting. Thus, Dex within PCA/Dex/gene nanoparticles created an anti-inflammatory effect and enhanced gene expression.


Subject(s)
Cell-Penetrating Peptides/pharmacokinetics , Dexamethasone/pharmacokinetics , Gene Transfer Techniques , Nanoparticles/administration & dosage , Animals , Brain-Derived Neurotrophic Factor/genetics , Brain-Derived Neurotrophic Factor/metabolism , Cell Line , Cell-Penetrating Peptides/administration & dosage , Connexin 26 , Connexins/genetics , Ear, Inner/cytology , Genetic Therapy/methods , Green Fluorescent Proteins/genetics , Lipids , Mice , Micelles , Nanoparticles/chemistry , Polyhydroxyethyl Methacrylate/analogs & derivatives , Polyhydroxyethyl Methacrylate/chemistry , RNA, Small Interfering/metabolism , Real-Time Polymerase Chain Reaction , Round Window, Ear/drug effects , Round Window, Ear/metabolism
20.
J Altern Complement Med ; 22(12): 964-969, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27603149

ABSTRACT

OBJECTIVES: Chronic hepatitis B management is commonly targeted at reducing viral replication. However, the currently available antiviral therapies are associated with some problems, including resistance and numerous adverse effects. Ginseng has been reported to be effective for treating viral infections such as influenza and human immunodeficiency virus. However, there are currently few studies on the effects of ginseng in chronic hepatitis B. Thus, this study investigated the effects of ginseng together with antiviral agents in chronic hepatitis B. SUBJECTS AND METHODS: This was a prospective, single-blinded, randomized controlled trial, and single-center study. Thirty-eight patients were enrolled. The control group (n = 19) was administered antiviral agents alone. The experimental group (n = 19) was administered antiviral agents along with Korean Red Ginseng powder capsules (each dose is 1 gram (two capsules), a one-day dose is 3 grams). The baseline characteristics did not differ between the two groups. Differences in several non-invasive fibrosis serologic markers (type IV collagen, hyaluronic acid, transforming growth factor-ß) and in the hepatitis B virus DNA levels were compared between the groups. RESULTS: The non-invasive fibrosis serologic markers were further decreased in the experimental group, with significant differences after treatment observed for hyaluronic acid (p = 0.032) and transforming growth factor-ß (p = 0.008), but not for type IV collagen (p = 0.174). CONCLUSIONS: This study suggests the possibility of Korean Red Ginseng as a complementary therapy for chronic hepatitis B.


Subject(s)
Antiviral Agents/therapeutic use , Hepatitis B, Chronic/drug therapy , Panax/chemistry , Plant Extracts/therapeutic use , Adult , Antiviral Agents/administration & dosage , Antiviral Agents/adverse effects , Biomarkers/blood , Drug Therapy, Combination , Female , Follow-Up Studies , Hepatitis B, Chronic/blood , Hepatitis B, Chronic/virology , Humans , Liver Cirrhosis/blood , Male , Middle Aged , Plant Extracts/administration & dosage , Plant Extracts/adverse effects
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