Therapeutic effect of quercetin polymeric nanoparticles on ischemia/reperfusion-induced acute kidney injury in mice.

Acute kidney injury (AKI) is known as a sudden episode of kidney injury, which happens suddenly within a few hours or a few days. Quercetin (3,3',4',5,7-pentahydroxyflavone) is a flavonoid found in plants. Quercetin is known to have several biological activities, such as anti-oxidant, anti-inflammatory, and anti-carcinogenic effects. However, low water solubility and bioavailability are the limitations of quercetin for its clinical applications. Moreover, ischemia/reperfusion (I/R) injury is a common cause of AKI. There are no satisfactory strategies for I/R-induced AKI. Developing suitable preventive or therapeutic intervention for AKI is an important and urgent issue. We investigated the benefit effect of synthesized polyethylene glycol (PEG) conjugated polyethyleneimine (PEI) nanoparticles for targeted delivery of quercetin on AKI in a mouse model. An I/R-induced AKI mouse model was used to evaluate the therapeutic effect of quercetin polymeric nanoparticles by intravenous injection. Biochemical changes for renal function in blood samples were analyzed. Histological and immunohistochemical changes were also analyzed. The biochemical changes of blood urea nitrogen (BUN), creatinine, and cystatin C were significantly increased in I/R-induced AKI mice, which could be significantly reversed by quercetin polymeric nanoparticles. Quercetin polymeric nanoparticles could also significantly decrease the histological lesions, positive staining for 3-nitrotyrosine and cyclooxygenase-2, and lipid peroxidation in the kidneys of I/R-induced AKI mice. These results demonstrate for the first time that quercetin polymeric nanoparticles possess therapeutic potential for the treatment of I/R-induced AKI in vivo.

Ferritin heavy chain mediates the protective effect of heme oxygenase-1 against oxidative stress.

The phenomenon that heme oxygenase-1 (HO-1) protects cell from injury yet its enzymatic product, iron, may facilitate generation of free radical has been long puzzling. Here we establish a functional connection between ferritin heavy chain (FHC) and HO-1. In human lupus nephritis HO-1 and FHC are colocalized within the glomeruli. In rodent anti-Thy1 (thymocyte antigen 1) induced glomerulonephritis, heme oxygenase blockade lowers the expression of FHC and accelerates mesangial cell death. Stimulation of heme oxygenase in cultured rat mesangial cell enhances its resistance to hydrogen peroxide, whereas FHC knockdown by RNA interference compromises this salutary effect. RNA interference of HO-1 makes the cell more susceptible to hydrogen peroxide, which can be rescued by forced expression of wild-type FHC but not mutants that lose the capacity of iron storage and ferroxidase activity. Phosphorylation of JunD was not sustained in these cells. Microarray analysis identifies four candidate transcriptional factors that may regulate the HO-1-induced transcription of FHC. Our results support the role of FHC in neutralizing the iron toxicity as well as mediating the protective effect of HO-1 in response to oxidative stress.

Titanium nanoparticle inhalation induces renal fibrosis in mice via an oxidative stress upregulated transforming growth factor-ß pathway.

Titanium dioxide nanoparticles (Nano-TiO2) are gradually being used extensively in clinical settings, industry, and daily life. Accumulation studies showed that Nano-TiO2 exposure is able to cause injuries in various animal organs, including the lung, liver, spleen, and kidney. However, it remains unclear whether exposure of Nano-TiO2 by inhalation causes renal fibrosis. Here, we investigated the role of reactive oxygen species (ROS)/reactive nitrogen species (RNS) related signaling molecules in chronic renal damage after Nano-TiO2 inhalation in mice. Mice were treated with Nano-TiO2 (0.1, 0.25, and 0.5 mg/week) or microparticle-TiO2 (0.5 mg/week) by nonsurgical intratracheal instillation for 4 weeks. The results showed that Nano-TiO2 inhalation increased renal pathological changes in a dose-dependent manner. No renal pathological changes were observed in microparticle-TiO2-instilled mice. Nano-TiO2 (0.5 mg/week) possessed the ability to precipitate in the kidneys, determined by transmission electron microscopy and increased serum levels of blood urea nitrogen. The expressions of markers of ROS/RNS and renal fibrosis markers, including nitrotyrosine, inducible nitric oxide synthase, hypoxia inducible factor-1α (HIF-1α), heme oxygenase 1, transforming growth factor-ß (TGFß), and collagen I, determined by immunohistochemical staining were increased in the kidneys. Furthermore, Nano-TiO2-induced renal injury could be mitigated by iNOS inhibitor aminoguanidine and ROS scavenger N-acetylcysteine treatment in transcription level. The in vitro experiments showed that Nano-TiO2 significantly and dose-dependently increased the ROS production and the expressions of HIF-1α and TGFß in human renal proximal tubular cells, which could be reversed by N-acetylcysteine treatment. Taken together, these results suggest Nano-TiO2 inhalation might induce renal fibrosis through a ROS/RNS-related HIF-1α-upregulated TGF-ß signaling pathway.

Protective Effects of Nootkatone on Renal Inflammation, Apoptosis, and Fibrosis in a Unilateral Ureteral Obstructive Mouse Model.

Nootkatone is one of the major active ingredients of Alpiniae oxyphyllae, which has been used as both food and medicinal plants for the treatment of diarrhea, ulceration, and enuresis. In this study, we aimed to investigate whether nootkatone treatment ameliorated the progression of chronic kidney diseases (CKD) and clarified its underlying mechanisms in an obstructive nephropathy (unilateral ureteral obstructive; UUO) mouse model. Our results revealed that nootkatone treatment preventively decreased the pathological changes and significantly mitigated the collagen deposition as well as the protein expression of fibrotic markers. Nootkatone could also alleviate oxidative stress-induced injury, inflammatory cell infiltration, and renal cell apoptotic death in the kidneys of UUO mice. These results demonstrated for the first time that nootkatone protected against the progression of CKD in a UUO mouse model. It may serve as a potential therapeutic candidate for CKD intervention.

Prevention of acute kidney injury by low intensity pulsed ultrasound via anti-inflammation and anti-apoptosis.

The therapeutic effects of low intensity pulsed ultrasound (LIPUS) on renal ischemia/reperfusion injury (IRI) with acute kidney injury (AKI) are still unclear. A renal tubule cell model under H2O2 or hypoxia/reoxygenation (H/R) conditions with or without LIPUS pre-treatment (1 MHz, 30 and 100 mW/cm2, 15 min) was used to test the in vitro effects of LIPUS. An AKI mouse model of unilateral IRI with nephrectomy of the contralateral kidney for 48 h with or without LIPUS treatment (3 MHz, 100 mW/cm2, 20 min/day) 5 day before IRI were used to investigate the in vivo effects of LIPUS. LIPUS significantly protected the renal tubule cell viability and prevented inflammatory signals against H2O2 challenge. LIPUS could inhibit the apoptosis-related molecular signals and increase the protein levels of endogenous antioxidant enzymes, α-Klotho, and Sirt1 in renal tubule cells after H/R challenge. LIPUS alleviated the increases in the serum levels of blood urea nitrogen, creatinine, and cystatin C, renal pathological changes and apoptosis-related molecular signals, and impaired antioxidant enzymes in AKI mice. The IRI-induced inflammatory responses in the kidneys and spleens could be reversed by LIPUS. These findings suggest that LIPUS treatment displays the benefits for renal protection in IRI-induced AKI mice.

Withaferin A protects against endoplasmic reticulum stress-associated apoptosis, inflammation, and fibrosis in the kidney of a mouse model of unilateral ureteral obstruction.

BACKGROUND: Withaferin A is a functional ingredient of a traditional medicinal plant, Withania somnifera, which has been broadly used in India for protecting against chronic diseases. This bioactive steroidal lactone possesses multiple functions such as anti-oxidation, anti-inflammation, and immunomodulation. Chronic kidney disease (CKD) is one of the major health problems worldwide with the high complication, morbidity, and mortality rates. The detailed effects and underlying mechanisms of withaferin A on CKD progression still remain to be clarified. PURPOSE: We aimed to investigate whether withaferin A treatment ameliorates the development of renal fibrosis and its related mechanisms in a CKD mouse model. METHODS: A mouse model of unilateral ureteral obstruction (UUO) was used to mimic the progression of CKD. Male adult C57BL/6J mice were orally administered with 3 mg/kg/day withaferin A for 14 consecutive days after UUO surgery. Candesartan (5 mg/kg/day) was used as a positive control. RESULTS: Both Withaferin A and candesartan treatments significantly ameliorated the histopathological changes and collagen deposition in the UUO kidneys. Withaferin A could significantly reverse the increases in the protein levels of pro-fibrotic factors (fibronectin, transforming growth factor-ß, and α-smooth muscle actin), inflammatory signaling molecules (phosphorylated nuclear factor-κB-p65, interleukin-1ß, and cyclooxygenase-2), and cleaved caspase-3, apoptosis, and infiltration of neutrophils in the UUO kidneys. The protein levels of endoplasmic reticulum (ER) stress-associated molecules (GRP78, GRP94, ATF4, CHOP, phosphorylated eIF2α, and cleaved caspase 12) were increased in the kidneys of UUO mice, which could be significantly reversed by withaferin A treatment. CONCLUSION: Withaferin A protects against the CKD progression that is, at least in part, associated with the moderation of ER stress-related apoptosis, inflammation, and fibrosis in the kidneys of CKD. Withaferin A may serve as a potential therapeutic agent for the development of CKD.

cAMP receptor protein regulates mouse colonization, motility, fimbria-mediated adhesion, and stress tolerance in uropathogenic Proteus mirabilis.

Cyclic AMP receptor protein (Crp) is a major transcriptional regulator in bacteria. This study demonstrated that Crp affects numerous virulence-related phenotypes, including colonization of mice, motility, fimbria-mediated adhesion, and glucose stress tolerance in uropathogenic Proteus mirabilis. Diabetic mice were more susceptible to kidney colonization by wild-type strain than nondiabetic mice, in which the crp mutant exhibited increased kidney colonization. Loss of crp or addition of 10% glucose increased the P. mirabilis adhesion to kidney cells. Direct negative regulation of pmpA (which encodes the major subunit of P-like fimbriae) expression by Crp was demonstrated using a reporter assay and DNase I footprinting. Moreover, the pmpA/crp double mutant exhibited reduced kidney adhesion comparable to that of the pmpA mutant, and mouse kidney colonization by the pmpA mutant was significantly attenuated. Hence, the upregulation of P-like fimbriae in the crp mutant substantially enhanced kidney colonization. Moreover, increased survival in macrophages, increased stress tolerance, RpoS upregulation, and flagellum deficiency leading to immune evasion may promote kidney colonization by the crp mutant. This is the first study to elucidate the role of Crp in the virulence of uropathogenic P. mirabilis, underlying mechanisms, and related therapeutic potential.

Advanced glycation end-products induce apoptosis in pancreatic islet endothelial cells via NF-κB-activated cyclooxygenase-2/prostaglandin E2 up-regulation.

Microvascular complications eventually affect nearly all patients with diabetes. Advanced glycation end-products (AGEs) resulting from hyperglycemia are a complex and heterogeneous group of compounds that accumulate in the plasma and tissues in diabetic patients. They are responsible for both endothelial dysfunction and diabetic vasculopathy. The aim of this study was to investigate the cytotoxicity of AGEs on pancreatic islet microvascular endothelial cells. The mechanism underlying the apoptotic effect of AGEs in pancreatic islet endothelial cell line MS1 was explored. The results showed that AGEs significantly decreased MS1 cell viability and induced MS1 cell apoptosis in a dose-dependent manner. AGEs dose-dependently increased the expressions of cleaved caspase-3, and cleaved poly (ADP-ribose) polymerase in MS1 cells. Treatment of MS1 cells with AGEs also resulted in increased nuclear factor (NF)-κB-p65 phosphorylation and cyclooxygenase (COX)-2 expression. However, AGEs did not affect the expressions of endoplasmic reticulum (ER) stress-related molecules in MS1 cells. Pretreatment with NS398 (a COX-2 inhibitor) to inhibit prostaglandin E2 (PGE2) production reversed the induction of cleaved caspase-3, cleaved PARP, and MS1 cell viability. Moreover, AGEs significantly increased the receptor for AGEs (RAGE) protein expression in MS1 cells, which could be reversed by RAGE neutralizing antibody. RAGE Neutralizing antibody could also reverse the induction of cleaved caspase-3 and cleaved PARP and decreased cell viability induced by AGEs. These results implicate the involvement of NF-κB-activated COX-2/PGE2 up-regulation in AGEs/RAGE-induced islet endothelial cell apoptosis and cytotoxicity. These findings may provide insight into the pathological processes within the pancreatic islet microvasculature induced by AGEs accumulation.

Induction of growth inhibition and G1 arrest in human cancer cell lines by relatively low-toxic diamantane derivatives.

We describe the discovery of a novel series of antitumor diamantane derivatives which induces G1 arrest in Colo 205 cells. Eight diamantane derivatives were screened for their activity in vitro against 60 human cancer cell lines in the National Cancer Institute (NCI)'s anticancer drug screen. The relationships between structure and in vitro antitumor activity are discussed. The structure-activity relationship (SAR) study of diamantane derivatives clarified that the conformation of 1,6-bis(4-(4-aminophenoxy)-phenyl)diamantane (1,6-DPDONH2) was essential for significant antitumor activity. Very strong growth inhibition of 1,6-DPDONH2 (NSC-706829) was observed against one colon cancer line (Colo 205), four melanoma lines (MALME-3M, M14, SK-MEL-5 and UACC-257) and two breast cancer lines (MDA-MB-435 and MDA-N) with GI50 <1.0 microM, i.e. below 0.01, 0.23, 0.48, 0.5, 0.32, 0.26 and 0.28 microM, respectively. 1,6-DPDONH2 also exhibited particular selectivity against one colon cancer line (Colo 205), four melanoma lines (MALME-3M, M14, SK-MEL-5 and UACC-257) and two breast cancer lines (MAD-MB-435 and MDA-N) with GI50 < or=0.5 microM. In the same cancer subpanel, the selectivity of 1,6-DPDONH2 between these seven most sensitive lines and the least sensitive line ranged from 40- to 100-fold. With the exception of melanoma lines, 1,6-bis(4-(4-amino-3-hydroxyphenoxy)-phenyl)diamantane (1,6-DPD/OH/NH2) (NSC-706831) possessed stronger activity than 1,6-DPDONH2 against almost all tested cancer lines. Very strong growth inhibition of 1,6-DPD/OH/NH2 was observed against one leukemia line (HL-60(TB)), one NSCLC line (HOP-92), one ovarian cancer line (OVCAR-8) and one breast cancer line (T-47D) with GI50 <1.0 microM, i.e. 0.50, 0.85, 0.62 and 0.75 microM, respectively.

In vitro and in vivo growth inhibition and G1 arrest in human cancer cell lines by diaminophenyladamantane derivatives.

We describe the discovery of a novel series of anticancer adamantane derivatives which induce G1 arrest in Colo 205 and HT 29 colon cancer cells. Seven adamantane derivatives were screened for their activity in vitro against 60 human cancer cell lines in the National Cancer Institute (NCI)'s Anticancer Drug Screen system. The relationships between structure and in vitro anticancer activity are discussed. 1,3-Bis(4-(4-amino-3-hydroxyphenoxy)phenyl)adamantane (1,3-DPA/OH/NH2) and 2,2-bis(4-(4-amino-3-hydroxyphenoxy)phenyl)adamantane (DPA) exhibited strong growth inhibitory on anticancer activities in vitro. The IC50s of 1,3-DPA/OH/NH2 (NSC-706835) and DPA (NSC-706832) were found to be < 3 microM against 45 (85%) and 48 (91%) cell lines, respectively. 2,2-Substituted adamantane derivatives exhibited stronger growth inhibition on anticancer activities in vitro than the corresponding 1,3-substituted analogs. Very strong growth inhibition of 2,2-bis(4-aminophenyl)adamantane (NSC-711117) was observed against two colon cancer lines (HT-29 and KM-12), one CNS cancer line (SF-295) and one breast cancer line (NCI/ADR-RES) with IC50 < 1.0 microM, i.e. 0.1, 0.01, 0.059 and 0.079 microM, respectively. In addition, we also examined the in vitro and in vivo effects of DPA on three human colon cancer cells. DPA-treated Colo 205 and HT-29 cells were arrested at G0/G1 as analyzed by flow cytometric analysis. The DPA-induced cell growth inhibition was irreversible after removal of DPA. The in vivo effect of tumor growth suppression by DPA was also observed on colon Colo 205 xenografts. No acute toxicity was observed after an i.p. challenge of DPA in ICR nude mice weekly. These results suggest that DPA appears to be a new potentially less toxic modality of cancer therapy.