Beneficial effect of trimetazidine on folic acid-induced acute kidney injury in mice: Role of HIF-1α/HO-1.

Acute kidney injury (AKI) is a complex syndrome associated with a decrease in renal function and a significant impact on patient outcomes. Injection of folic acid (FA) in mice is used for studying the pathogenesis of AKI. This study investigated the impact of trimetazidine (a metabolic modulator-antianginal drug; TMZ), against FA-induced AKI. AKI was induced by FA (250 mg/kg, ip) in mice. Two doses of TMZ were administered orally for 10 days. Administration of TMZ at a high dose (20 mg/kg) exhibited significant decreases in the renal somatic index (RSI), serum levels of lactate dehydrogenase (LDH), creatinine (Cr), blood urea nitrogen (1), and proteins level in urine. Moreover, TMZ significantly increased creatinine clearance (CCr), serum albumin, urine creatinine, and urine urea levels. This improvement in markers of kidney damage was associated with marked renal antioxidant effects (↓NO and ↓lipid peroxidation, normalized reduced glutathione (GSH) level and superoxide dismutase (SOD) activity, and increased HIF-1α/HO-1 level). Furthermore, TMZ significantly decreased FA-induced expression of MPO and inflammatory cytokine IL-18, TNF-α, and NF-κB p65 subunit. Renal apoptosis, along with apoptotic markers, were enhanced by FA injection and suppressed by TMZ administration (↓Caspase-3, ↓Bax, and ↑Bcl2 expression). Finally, TMZ amended FA-induced histopathological changes in kidneys. By mitigating functional alteration, oxidative stress, and preventing the development of inflammatory and apoptosis signals, TMZ provides dose-dependent defense against FA-induced AKI mainly via stimulation of hypoxia-inducible factor-1 alpha (HIF-1α)/heme oxygenase-1 (HO-1) pathway.

Bone Marrow-Derived RIPK3 Mediates Kidney Inflammation in Acute Kidney Injury.

BACKGROUND: Receptor-interacting protein kinase 3 (RIPK3), a component of necroptosis pathways, may have an independent role in inflammation. It has been unclear which RIPK3-expressing cells are responsible for the anti-inflammatory effect of overall Ripk3 deficiency and whether Ripk3 deficiency protects against kidney inflammation occurring in the absence of tubular cell death. METHODS: We used chimeric mice with bone marrow from wild-type and Ripk3-knockout mice to explore RIPK3's contribution to kidney inflammation in the presence of folic acid-induced acute kidney injury AKI (FA-AKI) or absence of AKI and kidney cell death (as seen in systemic administration of the cytokine TNF-like weak inducer of apoptosis [TWEAK]). RESULTS: Tubular and interstitial cell RIPK3 expressions were increased in murine AKI. Ripk3 deficiency decreased NF-κB activation and kidney inflammation in FA-AKI but did not prevent kidney failure. In the chimeric mice, RIPK3-expressing bone marrow-derived cells were required for early inflammation in FA-AKI. The NLRP3 inflammasome was not involved in RIPK3's proinflammatory effect. Systemic TWEAK administration induced kidney inflammation in wild-type but not Ripk3-deficient mice. In cell cultures, TWEAK increased RIPK3 expression in bone marrow-derived macrophages and tubular cells. RIPK3 mediated TWEAK-induced NF-κB activation and inflammatory responses in bone marrow-derived macrophages and dendritic cells and in Jurkat T cells; however, in tubular cells, RIPK3 mediated only TWEAK-induced Il-6 expression. Furthermore, conditioned media from TWEAK-exposed wild-type macrophages, but not from Ripk3-deficient macrophages, promoted proinflammatory responses in cultured tubular cells. CONCLUSIONS: RIPK3 mediates kidney inflammation independently from tubular cell death. Specific targeting of bone marrow-derived RIPK3 may limit kidney inflammation without the potential adverse effects of systemic RIPK3 targeting.

Synthesis of biocompatible nanocrystalline cellulose against folate receptors as a novel carrier for targeted delivery of doxorubicin.

We designed amine-functionalized nanocrystalline cellulose grafted folic acid/magnetic nanoparticles (AF-NCC/Fe3O4 NPs) against folate receptors for targeted delivery of doxorubicin (DOX). Toxicity is a major side effect of DOX, damaging vital organs such as the heart, kidney, and liver; for example, it causes dilated cardiomyopathy and hepatotoxicity. Accordingly, we aimed to reduce this adverse effect and increase the targeted delivery of DOX to the right point of cancer cells by using the unique features of cancer cells. The characterizations were approved in each step using Fourier transform infrared (FTIR), scanning electron microscope (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray (EDX), zeta potential, and dynamic light scattering (DLS) analysis techniques. Encapsulation efficacy of AF-NCC/Fe3O4 NPs was 99.6%; drug release investigations showed excellent stability in physiological conditions (pH âˆ¼ 7.4) and a high release rate in the low pH condition of cancer environments (pH âˆ¼ 5.0). The hemolysis assay and Masson's trichrome and hematoxylin and eosin (H&E) staining results showed that the nanocarrier was entirely biocompatible. In vitro cell viability study approved that the designed nanocarrier increased the therapeutic effects of DOX on Saos-2 cells. The cellular internalization results displayed a high percentage of uptake within 2 h. Real-time reverse transcriptase-polymerase chain reaction (RT-PCR) was applied for the evaluation of tumor protein p53 (p53), p21, and Bcl-2-associated X protein (Bax). DOX exerted its effects through DNA damage and oxidative stress that led to p53 upregulation, and p53 inhibited cell cycle progression. This arrest initiated apoptosis and inhibited cell migration. In summary, encapsulating DOX in AF-NCC/Fe3O4 NPs dramatically decreases the toxic effects of this chemotherapeutic agent on vital organs, especially on the heart. This smart nanocarrier increases the delivery of DOX using acid folic on its surface and also enhances the DOX release in the acidic environment of cancer cells. DOX exerts its therapeutic effects by the initiation of apoptosis and inhibition of migration.

Comparison of two different toxin-induced kidney fibrosis models in terms of inflammatory responses.

Chronic kidney disease (CKD) is characterized by persistent abnormalities in kidney function, accompanied by structural changes. Interstitial fibrosis, characterized by the accumulation of extracellular matrix (ECM) proteins, is frequently detected during CKD development. Given the multiple underlying causes of CKD, numerous animal models have been developed to advance our understanding of human nephropathy. Herein, we compared two reliable toxin-induced mouse kidney fibrosis models in terms of fibrosis and inflammation. Administration of folic acid (250 mg/kg, intraperitoneal injection) or an adenine diet (0.25 % for three weeks) afforded similar effects on kidney function, as detected by increased serum nitrogen levels. In addition, the kidneys exhibited a similar extent of tubule dilation and kidney damage. The degree of fibrosis was compared using various biological methods. Although both models developed a significant fibrotic phenotype, the adenine diet-fed model showed a marginally higher increase in fibrosis than the folic acid model, as reflected by increased kidney ECM gene and protein levels. We further compared inflammatory responses in the kidneys. Interestingly, pro-inflammatory responses, including cytokine expression and immune cell infiltration, were significantly increased in adenine diet-fed kidneys. Furthermore, collagen expression was identified in the macrophage-infiltrated region, implying the importance of inflammation in fibrogenesis. Collectively, we observed that the adenine diet-fed kidney fibrosis model presented a higher inflammatory response with increased fibrosis when compared with the folic acid-induced kidney fibrosis model, indicating the importance of the inflammatory response in fibrosis development.

The NLRP3 inhibitor dapansutrile attenuates folic acid induced nephrotoxicity via inhibiting inflammasome/caspase-1/IL axis and regulating autophagy/proliferation.

AIMS: Chemical renal toxicity is common and has limited therapeutic interventions. The NLRP3 inhibitor dapansutrile (DAPA) undergoes clinical phase II trials and it shows promising beneficial effects in various inflammatory diseases. The current study aims at evaluating the effect of DAPA on folic acid (FA) induced acute kidney injury (AKI) and its possible transition to chronic injury. MATERIALS AND METHODS: Two treatment protocols were studied depending on DAPA injection timing. A prophylactic protocol involving the injection of DAPA (0.2 mg/kg) daily for seven days before FA challenge and a therapeutic protocol where DAPA was injected after FA. Each protocol included four groups of rats: control group, DAPA group, FA group and DAPA+FA group. Serum creatinine, urea and uric acid were measured. Also, kidney injury, necrosis and fibrosis percentage in addition to infiltration of CD68 positive cells were evaluated. Activation markers of inflammasome and the expression of Ki-67 and LC-3 were measured. KEY FINDINGS: Results showed an improvement in renal tissue integrity and a significant decrease in kidney function biomarkers, caspase-1, IL-1ß and IL-18 by DAPA injection (p < 0.05). In addition, DAPA decreased the proliferation marker Ki-67 and the autophagic marker LC-3 (p < 0.01). SIGNIFICANCE: DAPA potentially alleviates FA induced nephrotoxicity through targeting inflammasome/caspase-1/IL axis. Moreover, it shows a regulatory effect on renal regeneration and autophagy.

Efficient Design to Monitor the Site-specific Sustained Release of a Non-Emissive Anticancer Drug.

A pH-responsive smart nanocarrier with significant components was synthesized by conjugating the non-emissive anticancer drug methyl orange and polyethylene glycol derived folate moiety to the backbone of polynorbornene. Complete synthesis procedure and characterization methods of three monomers included in the work: norbornene-derived Chlorambucil (Monomer 1), norbornene grafted with polyethylene glycol, and folic acid (Monomer 2) and norbornene attached methyl orange (Monomer 3) connected to the norbornene backbone through ester linkage were clearly discussed. Finally, the random copolymer CHO PEG FOL METH was synthesized by ring-opening metathesis polymerization (ROMP) using Grubbs' second-generation catalyst. Advanced polymer chromatography (APC) was used to find the final polymer's molecular weight and polydispersity index (PDI). Dynamic light scattering, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were utilized to explore the prodrug's size and morphology. Release experiments of the anticancer drug, Chlorambucil and the coloring agent, methyl orange, were performed at different pH and time. Cell viability assay was carried out for determining the rate of survived cells, followed by the treatment of our final polymer named CHO PEG FOL METH.

Natural killer T cell/IL-4 signaling promotes bone marrow-derived fibroblast activation and M2 macrophage-to-myofibroblast transition in renal fibrosis.

Renal fibrosis is a histological manifestation of chronic kidney disease. Natural killer T (NKT) cells have a critical role in the pathogenesis of fibrotic disorder. However, the role of NKT cells in regulating kidney fibrosis remains largely unknown. In the current study, we showed that the percentages of NKT+ cells and NKT+-IL-4+ cells were notably increased in folic acid (FA) and obstructive nephropathy. CD1d deficiency protected mice from renal fibrosis induced by FA and obstructive injury. Specifically, Loss of CD1d reduced bone marrow-derived myofibroblasts and CD206+/α-smooth muscle actin+ cells in the kidneys of injured mice. But mice treated with α-galactosylceramide (α-GC, a specific activator of NKT cells) developed more severe fibrosis, accumulated more myeloid myofibroblasts and M2 macrophages-myofibroblasts transition (M2MMT) cells in FA injured kidneys. Furthermore, IL-4 expression was markedly reduced in CD1d deficiency mice but increased in α-GC-treated mice. Administration of IL-4 abrogates the inhibiting effect of CD1d deficiency on renal fibrosis, bone marrow-derived fibroblasts activation, and M2MMT in FA injured kidneys. Conversely, pharmacological inhibition of IL-4 attenuated the development of renal fibrosis, decreased bone marrow-derived myofibroblasts, and suppressed M2MMT. Thus, this study revealed a novel role of NKT cells in the bone marrow-derived fibroblasts activation and M2MMT during renal fibrosis. Targeting NKT cell/IL-4 signaling may be an effective treatment for renal fibrosis.

Sonochemical preparation of folate-decorated reductive-responsive carboxymethylcellulose-based nanocapsules for targeted drug delivery.

In this study, a biocompatible folate-decorated reductive-responsive carboxymethylcellulose-based nanocapsules (FA-RCNCs) were designed and prepared via sonochemical method for targeted delivery and controlled release of hydrophobic drugs. The shell of FA-RCNCs was cross-linked by disulfide bonds formed from hydrosulfuryl groups on the thiolated carboxymethylcellulose (TCMC) and encapsulated hydrophobic drug dispersed in the oil phase into nanocapsules. Moreover, the size and morphology of drug loaded FA-RCNCs were characterized by DLS, SEM and CLSM which indicated that the synthesized nanocapsules have suitable size range and excellent stability for circulating in the bloodstream. The drug release rate of FA-RCNCs could be controlled by adjusting their sizes and shell thickness, which could be dominated by the concentration of TCMC and sonochemical conditions. Furthermore, the obtained FA-RCNCs could be ingested into Hela cells via folate-receptor (FR)-mediated endocytosis and quickly release drugs under reductive environment, which demonstrated that FA-RCNCs could become potential hydrophobic drugs carries for cancer therapy.

Genetic and pharmacological inhibition of fatty acid-binding protein 4 alleviated inflammation and early fibrosis after toxin induced kidney injury.

Considerable data have suggested that acute kidney injury (AKI) is often incompletely repaired and could lead to chronic kidney disease (CKD). As we known, toxin-induced nephropathy triggers the rapid production of proinflammatory mediators and the prolonged inflammation allows the injured kidneys to develop interstitial fibrosis. In our previous study, fatty acid-binding protein 4 (Fabp4) has been reported to be involved in the process of AKI. However, whether Fabp4 plays crucial roles in toxin-induced kidney injury remained unclear. To explore the effect and mechanism of Fabp4 on toxin induced kidney injury, folic acid (FA) and aristolochic acid (AA) animal models were used. Both FA and AA injected mice developed severe renal dysfunction and dramatically inflammatory response (IL-6, MCP1 and TNF-a), which further lead to early fibrosis confirmed by the accumulation of extracellular matrix proteins (α-Sma, Fn, Col1 and Col4). Importantly, we found that FA and AA induced-kidney injury triggered the high expression of Fabp4 mRNA/protein in tubular epithelial cells. Furthermore, pharmacological and genetic inhibition of Fabp4 significantly attenuated FA and AA induced renal dysfunction, pathological damage, and early fibrosis via the regulation of inflammation, which is mediated by suppressing p-p65/p-stat3 expression via enhancing Pparγ activity. In summary, Fabp4 in tubular epithelial cells exerted the deleterious effects during the recovery of FA and AA induced kidney injury and the inhibition of Fabp4 might be an effective therapeutic strategy against the progressive AKI.

Diet Significantly Influences the Immunopathology and Severity of Kidney Injury in Male C57Bl/6J Mice in a Model Dependent Manner.

Diet is a leading causative risk factor for morbidity and mortality worldwide, yet it is rarely considered in the design of preclinical animal studies. Several of the nutritional inadequacies reported in Americans have been shown to be detrimental to kidney health; however, the mechanisms responsible are unclear and have been largely attributed to the development of diabetes or hypertension. Here, we set out to determine whether diet influences the susceptibility to kidney injury in male C57Bl/6 mice. Mice were fed a standard chow diet, a commercially available "Western" diet (WD), or a novel Americanized diet (AD) for 12 weeks prior to the induction of kidney injury using the folic acid nephropathy (FAN) or unilateral renal ischemia reperfusion injury (uIRI) models. In FAN, the mice that were fed the WD and AD had worse histological evidence of tissue injury and greater renal expression of genes associated with nephrotoxicity and monocyte infiltration as compared to mice fed chow. Mice fed the AD developed more severe renal hypertrophy following FAN, and gene expression data suggest the mechanism for FAN differed among the diets. Meanwhile, mice fed the WD had the greatest circulating interleukin-6 concentrations. In uIRI, no difference was observed in renal tissue injury between the diets; however, mice fed the WD and AD displayed evidence of suppressed inflammatory response. Taken together, our data support the hypothesis that diet directly impacts the severity and pathophysiology of kidney disease and is a critical experimental variable that needs to be considered in mechanistic preclinical animal studies.

Fluorofenidone attenuates renal fibrosis by inhibiting the mtROS-NLRP3 pathway in a murine model of folic acid nephropathy.

Fluorofenidone (AKF-PD) is a novel pyridone agent that reduces the deposition of extracellular matrix (ECM) in various models of renal fibrosis. However, there are no reports on the effect of AKF-PD in preventing fibrosis in the folic acid nephropathy model. Besides, the mechanisms of action of AKF-PD in preventing renal fibrosis are not fully understood. In the study, we observed that AKF-PD reduced folate-induced kidney injury, ameliorated the deterioration of renal function, and suppressed the deposition of ECM by decreasing the expression of collagen I, collagen III, transforming growth factor-ß (TGF-ß), fibronectin (FN), and alpha smooth muscle actin (α-SMA) in the folic acid nephropathy model. Additionally, AKF-PD suppressed the activation of the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome to reduce the production of caspase-1 and IL-1ß, and alleviated mitochondrial oxidative damage by promoting mitochondrial energy metabolism and reducing the expression of NADPH oxidase 4 (NOX4). The results of in vitro experiments demonstrated that AKF-PD suppressed NLRP3 inflammasome activation in activated peritoneal-derived macrophages (PDMs) and renal tubular epithelial cells (RTECs). AKF-PD increased the intracellular ATP content and decreased the expression of NOX4, while preventing the excessive production of mitochondrial reactive oxygen species (mtROS) in activated PDMs. In conclusion, this study demonstrated that AKF-PD inhibited renal fibrosis by suppressing the mtROS-NLRP3 pathway in the folic acid nephropathy model. These findings provide new evidence in support of the clinical use of AKF-PD in the treatment of diseases related to renal fibrosis.

Study on the optical and biological properties in vitro of IR808-PEG-FA.

IR808, an IR780 derivative, is capable of fluorescently imaging and photodynamic therapy in vitro and in vivo. However, its application is greatly hampered by hydrophobicity, toxicity and nonspecific delivery to the targeting tissue and that causes accumulation in the liver and kidney. In order to overcome these limitations, we prepared IR808-PEG-FA from IR808, amino-terminated poly(ethylene glycol) (NH2 -PEG-NH2 , denoted as PEG) and folate (FA). PEG, an accepted hydrophilic medicinal agent, was introduced to improve hydrophobicity, and FA was used to increase targeting ability of the conjugate. The obtained product provides a good water solubility and stronger light intensity in near infrared (NIR)-imaging, and CCK-8 test demonstrated which had no appreciable toxicity. In addition, the cell uptake results indicated that IR808-PEG-FA was specifically targeted to positive tumors cells with folate receptor (FR) compared with IR808, and thus it may be used as a novel diagnostic agent or imaging-guided agent for cancer treatment. So this article provides a way to improve hydrophobicity, optical stability and targeting ability in the field of nano-probe for fluorochromes.

Effective Nephroprotection Against Acute Kidney Injury with a Star-Shaped Polyglutamate-Curcuminoid Conjugate.

The lack of effective pharmacological treatments for acute kidney injury (AKI) remains a significant public health problem. Given the involvement of apoptosis and regulated necrosis in the initiation and progression of AKI, the inhibition of cell death may contribute to AKI prevention/recovery. Curcuminoids are a family of plant polyphenols that exhibit attractive biological properties that make them potentially suitable for AKI treatment. Now, in cultured tubular cells, we demonstrated that a crosslinked self-assembled star-shaped polyglutamate (PGA) conjugate of bisdemethoxycurcumin (St-PGA-CL-BDMC) inhibits apoptosis and necroptosis induced by Tweak/TNFα/IFNγ alone or concomitant to caspase inhibition. St-PGA-CL-BDMC also reduced NF-κB activation and subsequent gene transcription. In vivo, St-PGA-CL-BDMC prevented renal cell loss and preserved renal function in mice with folic acid-induced AKI. Mechanistically, St-PGA-CL-BDMC inhibited AKI-induced apoptosis and expression of ferroptosis markers and also decreased the kidney expression of genes involved in tubular damage and inflammation, while preserving the kidney expression of the protective factor, Klotho. Thus, due to renal accumulation and attractive pharmacological properties, the application of PGA-based therapeutics may improve nephroprotective properties of current AKI treatments.

Extra-Large Gα Protein (XLαs) Deficiency Causes Severe Adenine-Induced Renal Injury with Massive FGF23 Elevation.

Fibroblast growth factor-23 (FGF23) is critical for phosphate and vitamin D homeostasis. Cellular and molecular mechanisms underlying FGF23 production remain poorly defined. The extra-large Gα subunit (XLαs) is a variant of the stimulatory G protein alpha-subunit (Gsα), which mediates the stimulatory action of parathyroid hormone in skeletal FGF23 production. XLαs ablation causes diminished FGF23 levels in early postnatal mice. Herein we found that plasma FGF23 levels were comparable in adult XLαs knockout (XLKO) and wild-type littermates. Upon adenine-rich diet-induced renal injury, a model of chronic kidney disease, both mice showed increased levels of plasma FGF23. Unexpectedly, XLKO mice had markedly higher FGF23 levels than WT mice, with higher blood urea nitrogen and more severe tubulopathy. FGF23 mRNA levels increased substantially in bone and bone marrow in both genotypes; however, the levels in bone were markedly higher than in bone marrow. In XLKO mice, a positive linear correlation was observed between plasma FGF23 and bone, but not bone marrow, FGF23 mRNA levels, suggesting that bone, rather than bone marrow, is an important contributor to severely elevated FGF23 levels in this model. Upon folic acid injection, a model of acute kidney injury, XLKO and WT mice exhibited similar degrees of tubulopathy; however, plasma phosphate and FGF23 elevations were modestly blunted in XLKO males, but not in females, compared to WT counterparts. Our findings suggest that XLαs ablation does not substantially alter FGF23 production in adult mice but increases susceptibility to adenine-induced kidney injury, causing severe FGF23 elevations in plasma and bone.

Characterization of Matricellular Protein Expression Signatures in Mechanistically Diverse Mouse Models of Kidney Injury.

Fibrosis is the most common pathophysiological manifestation of Chronic Kidney Disease (CKD). It is defined as excessive deposition of extracellular matrix (ECM) proteins. Embedded within the ECM are a family of proteins called Matricellular Proteins (MCPs), which are typically expressed during chronic pathologies for ECM processing. As such, identifying potential MCPs in the pathological secretome of a damaged kidney could serve as diagnostic/therapeutic targets of fibrosis. Using published RNA-Seq data from two kidney injury mouse models of different etiologies, Folic Acid (FA) and Unilateral Ureteral Obstruction (UUO), we compared and contrasted the expression profile of various members from well-known MCP families during the Acute and Fibrotic injury phases. As a result, we identified common and distinct MCP expression signatures between both injury models. Bioinformatic analysis of their differentially expressed MCP genes revealed similar top annotation clusters from Molecular Function and Biological Process networks, which are those commonly involved in fibrosis. Using kidney lysates from FA- and UUO-injured mice, we selected MCP genes from our candidate list to confirm mRNA expression by Western Blot, which correlated with injury progression. Understanding the expressions of MCPs will provide important insight into the processes of kidney repair, and may validate MCPs as biomarkers and/or therapeutic targets of CKD.

Folate-chitosan nanoparticles triggered insulin cellular uptake and improved in vivo hypoglycemic activity.

The aim of this study was to prove a prolonged control of glucose levels, in rats, by the oral use of insulin folate-chitosan nanoparticles (FA-CS NPs). It was possible to prepare positively charged NPs with an average particle size of 288 ±â€¯5.11 nm and >80% entrapment efficiency. The system was able to enhance the stability of insulin in presence of GIT enzymes, with less than 10% release at pH 1.2 and an 8 hr released amount of 38.92 ±â€¯4.52% in PBS pH 7.4. A 5 fold enhancement in insulin intestinal permeability and cellular uptake over insulin solution was proven. The cellular uptake pathways was found to occur by several mechanisms. Besides, cell compatibility and absence of histopathological alterations was also demonstrated. Finally, a controlled blood glucose level for 8 h in rats. These results anticipated FA-CS NPs as a promising oral insulin candidate.

Dual-ligand functionalized carbon nanodots as green fluorescent nanosensors for cellular dual receptor-mediated targeted imaging.

The conjugation of ligands to nanoparticles as drug delivery systems that target specific cells is a promising approach for the delivery of therapeutic agents to tumor cells. Herein, we prepared green-emission fluorescent carbon nanodots (CNDs) by a facile hydrothermal method with d-(+)-glucosamine hydrochloride and l-aspartic acid as the precursors, then covalently conjugated with folate (FA), polyethyleneimine (PEI) and hyaluronic acid (HA) to develop dual ligand-decorated nanocarriers (FA-PEI-HA-CNDs) for the targeted imaging of cancer cells. FA-PEI-HA-CNDs integrated the excellent fluorescence property of CNDs, and can be used for the real-time and noninvasive location tracking of cancer cells. The cellular uptake study demonstrated that FA-PEI-HA-CNDs markedly improved the internalization efficiency in A-549 cells via folate/CD44 receptor-mediated endocytosis in comparison with that of the A549 cells pretreated with excess FA, HA, and FA and HA. Therefore, these dual folate/CD44 receptor-targeted CNDs (FA-PEI-HA-CNDs) show promising potential for cancer detection, drug delivery, and individualized treatment as performance platforms.

Inhibition of Kirsten-Ras reduces fibrosis and protects against renal dysfunction in a mouse model of chronic folic acid nephropathy.

Chronic Kidney Disease is a growing problem across the world and can lead to end-stage kidney disease and cardiovascular disease. Fibrosis is the underlying mechanism that leads to organ dysfunction, but as yet we have no therapeutics that can influence this process. Ras monomeric GTPases are master regulators that direct many of the cytokines known to drive fibrosis to downstream effector cascades. We have previously shown that K-Ras is a key isoform that drives fibrosis in the kidney. Here we demonstrate that K-Ras expression and activation are increased in rodent models of CKD. By knocking down expression of K-Ras using antisense oligonucleotides in a mouse model of chronic folic acid nephropathy we can reduce fibrosis by 50% and prevent the loss of renal function over 3 months. In addition, we have demonstrated in vitro and in vivo that reduction of K-Ras expression is associated with a reduction in Jag1 expression; we hypothesise this is the mechanism by which targeting K-Ras has therapeutic benefit. In conclusion, targeting K-Ras expression with antisense oligonucleotides in a mouse model of CKD prevents fibrosis and protects against renal dysfunction.

Renal Reabsorption of Folates: Pharmacological and Toxicological Snapshots.

Folates are water-soluble B9 vitamins that serve as one-carbon donors in the de novo synthesis of thymidylate and purines, and in the conversion of homocysteine to methionine. Due to their key roles in nucleic acid synthesis and in DNA methylation, inhibiting the folate pathway is still one of the most efficient approaches for the treatment of several tumors. Methotrexate and pemetrexed are the most prescribed antifolates and are mainly used in the treatment of acute myeloid leukemia, osteosarcoma, and lung cancers. Normal levels of folates in the blood are maintained not only by proper dietary intake and intestinal absorption, but also by an efficient renal reabsorption that seems to be primarily mediated by the glycosylphosphatidylinositol- (GPI) anchored protein folate receptor α (FRα), which is highly expressed at the brush-border membrane of proximal tubule cells. Folate deficiency due to malnutrition, impaired intestinal absorption or increased urinary elimination is associated with severe hematological and neurological deficits. This review describes the role of the kidneys in folate homeostasis, the molecular basis of folate handling by the kidneys, and the use of high dose folic acid as a model of acute kidney injury. Finally, we provide an overview on the development of folate-based compounds and their possible therapeutic potential and toxicological ramifications.

Development of an interactive tumor vascular suppression strategy to inhibit multidrug resistance and metastasis with pH/H2O2 responsive and oxygen-producing nanohybrids.

An ideal cancer therapeutic strategy should not only reverse multidrug resistance (MDR), but also prevent cancer metastasis. In this study, bovine serum albumin (BSA) was hybridized with Mn2+via biomineralization to develop a hybrid protein oxygen nanocarrier, which contained doxorubicin (DOX) and small interfering RNA (siRNA). The nanohybrid has the function of producing oxygen and chemotherapy synergistic gene therapy. FA-BSA-MnO2/DOX/siRNA was favorable for increasing the sensitivity of MCF-7/ADR cells to DOX. Moreover, FA-BSA-MnO2/DOX/siRNA NPs were also able to generate oxygen (O2) by reaction with endogenous hydrogen peroxide (H2O2) in tumor, thereby down-regulating the expression of hypoxia inducible factor-1α (HIF-1α), and then the expression of the vascular endothelial growth factor (VEGF) was down-regulated. At the same time, siRNA can directly or indirectly suppress the expression of the VEGF and HIF-1α. Therefore, the combination of two pathways and the chemo-gene therapy strategy can interactively overcome tumor hypoxia-associated MDR and metastasis, which will enhance therapeutic efficacy in the future.