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Radiation therapy is one of the most commonly used cancer treatments. However, it has important concerns such as damage to normal tissues around cancers and radioresistance. To overcome these problems, combination therapy using radiosensitizer and radiotherapy will be a good alternative. The present study investigated the effects of AZD7648 on overcoming radioresistance as well as radiosensitizing in Hep3B xenografts and cells. The results showed that AZD7648 enhanced ionizing radiation (IR)-induced tumor growth not only in radiosensitive but also radioresistant tumors. In particular, the combination of AZD7648 with radiation reduced the expression of hypoxia induce factor-1α (HIF-1α) in radioresistant tumors. In vitro studies, AZD7648 plus IR increased IR-induced G2/M arrest and regulated cell cycle checkpoints such as cyclinB1, p-cdc2 in normoxia but not in hypoxia. AZD7648 induced more radiation-mediated ROS than radiation only under normoxia, but these ROS were not altered by AZD7648 under hypoxia. Interestingly, AZD7648 downregulated HIF-1α expression level under CoCl 2 -treated hypoxic condition but not in normoxic condition. In conclusion, AZD7648 synergistically increased radiosensitivity through accumulating IR-induced G2/M arrest and further improved radioresistance via regulation of HIF-1α. The present data suggest that AZD7648 may be a strong radiosensitizer in radioresistant as well as radiosensitive cancers., Competing Interests: None., (AJCR Copyright © 2023.)

Background: Non-alcoholic fatty liver disease (NAFLD) has been increasing in association with the epidemic of obesity and diabetes. Peroxisomes are single membrane-enclosed organelles that play a role in the metabolism of lipid and reactive oxygen species. The present study examined the role of peroxisomes in high-fat diet (HFD)-induced NAFLD using fenofibrate, a peroxisome proliferator-activated receptor α (PPARα) agonist., Methods: Eight-week-old male C57BL/6J mice were fed either a normal diet or HFD for 12 weeks, and fenofibrate (50 mg/kg/day) was orally administered along with the initiation of HFD., Results: HFD-induced liver injury as measured by increased alanine aminotransferase, inflammation, oxidative stress, and lipid accumulation was effectively prevented by fenofibrate. Fenofibrate significantly increased the expression of peroxisomal genes and proteins involved in peroxisomal biogenesis and function. HFD-induced attenuation of peroxisomal fatty acid oxidation was also significantly restored by fenofibrate, demonstrating the functional significance of peroxisomal fatty acid oxidation. In Ppara deficient mice, fenofibrate failed to maintain peroxisomal biogenesis and function in HFD-induced liver injury., Conclusion: The present data highlight the importance of PPARα-mediated peroxisomal fitness in the protective effect of fenofibrate against NAFLD.

Diabetic kidney disease (DKD) is now a pandemic worldwide, and novel therapeutic options are urgently required. Adenosine, an adenosine triphosphate metabolite, plays a role in kidney homeostasis through interacting with four types of adenosine receptors (ARs): A1AR, A2AAR, A2BAR, and A3AR. Increasing evidence highlights the role of adenosine and ARs in the development and progression of DKD: 1) increased adenosine in the plasma and urine of diabetics with kidney injury, 2) increased expression of each of the ARs in diabetic kidneys, 3) the protective effect of coffee, a commonly ingested nonselective AR antagonist, on DKD, and 4) the protective effect of AR modulators in experimental DKD models. We propose AR modulators as a new therapeutic option to treat DKD. Detailed mechanistic studies on the pharmacology of AR modulators will help us to develop effective first-in-class AR modulators against DKD.

Src family kinases (SFKs) have been implicated in the pathogenesis of kidney fibrosis. However, the specific mechanism by which SFKs contribute to the progression of diabetic kidney disease (DKD) remains unclear. Our preliminary transcriptome analysis suggested that SFK expression was increased in diabetic kidneys and that the expression of Fyn (a member of the SFKs), along with genes related to unfolded protein responses from the endoplasmic reticulum (ER) stress signaling pathway, was upregulated in the tubules of human diabetic kidneys. Thus, we examined whether SFK-induced ER stress is associated with DKD progression. Mouse proximal tubular (mProx24) cells were transfected with Fyn or Lyn siRNA and exposed to high glucose and palmitate (HG-Pal). Streptozotocin-induced diabetic rats were treated with KF-1607, a novel pan-Src kinase inhibitor (SKI) with low toxicity. The effect of KF-1607 was compared to that of losartan, a standard treatment for patients with DKD. Among the SFK family members, the Fyn and Lyn kinases were upregulated under diabetic stress. HG-Pal induced p70S6 kinase and JNK/CHOP signaling and promoted tubular injury. Fyn knockdown but not Lyn knockdown inhibited this detrimental signaling pathway. In addition, diabetic rats treated with KF-1607 showed improved kidney function and decreased ER stress, inflammation, and fibrosis compared with those treated with losartan. Collectively, these findings indicate that Fyn kinase is a specific member of the SFKs implicated in ER stress activation leading to proximal tubular injury in the diabetic milieu and that pan-SKI treatment attenuates kidney injury in diabetic rats. These data highlight Fyn kinase as a viable target for the development of therapeutic agents for DKD., (© 2022. The Author(s).)

Kidney disease is becoming a global public health issue. Acute kidney injury (AKI) and chronic kidney disease (CKD) have serious adverse health outcomes. However, there is no effective therapy to treat these diseases. Lactoferrin (LF), a multi-functional glycoprotein, is protective against various pathophysiological conditions in various disease models. LF shows protective effects against AKI and CKD. LF reduces markers related to inflammation, oxidative stress, apoptosis, and kidney fibrosis, and induces autophagy and mitochondrial biogenesis in the kidney. Although there are no clinical trials of LF to treat kidney disease, several clinical trials and studies on LF-based drug development are ongoing. In this review, we discussed the possible kidney protective mechanisms of LF, as well as the pharmacological and therapeutic advances. The evidence suggests that LF may become a potent pharmacological agent to treat kidney diseases.

Non-alcoholic fatty liver disease (NAFLD) is a global clinical problem. The MD2-TLR4 pathway exacerbates NAFLD progression by promoting inflammation. Long-term exercise is considered to improve NAFLD but the underlying mechanism is still unclear. In this study, we examined the protective effect and molecular mechanism of exercise on high-fat diet (HFD)-induced liver injury. In an HFD-induced NAFLD mouse model, exercise training significantly decreased hepatic steatosis and fibrosis. Interestingly, exercise training blocked the binding of MD2-TLR4 and decreased the downstream inflammatory response. Irisin is a myokine that is highly expressed in response to exercise and exerts anti-inflammatory effects. We found that circulating irisin levels and muscle irisin expression were significantly increased in exercised mice, suggesting that irisin could mediate the effect of exercise on NAFLD. In vitro studies showed that irisin improved lipid metabolism, fibrosis, and inflammation in palmitic acid (PA)-stimulated AML12 cells. Moreover, binding assay results showed that irisin disturbed MD2-TLR4 complex formation by directly binding with MD2 but not TLR4, and interfered with the recognition of stimuli such as PA and lipopolysaccharide with MD2. Our study provides novel evidence that exercise-induced irisin inhibits inflammation via competitive binding with MD2 to improve NAFLD. Thus, irisin could be considered a potential therapy for NAFLD.

Hypercholesterolemia, characterized by an increase in plasma low-density lipoprotein (LDL) cholesterol and total cholesterol (TC), is the leading cause of non-alcoholic fatty liver disease (NAFLD). The present study examined the effect of Heukcha extract (HCE), a naturally post-fermented green tea extract, on diet-induced hypercholesterolemia and related NAFLD in hamsters that metabolize lipids in a similar fashion to humans. The 10-week-old golden Syrian hamsters were fed a normal diet (ND) or a high cholesterol diet (HCD) containing 0.2% cholesterol and 10% lard, and some were also given HCE (200 or 500 mg/kg/day) orally for 12 weeks. The HCE did not affect the body weight gain, food intake, or the calorie intake. HCD significantly (p < 0.05) increased LDL (0.9 to 2.1 mmol/L), TC (2.7 to 7.8 mmol/L), and triglyceride (TG; 2.3 to 4.0 mmol/L), which was significantly decreased by 27.7%, 17.3%, and 60%, respectively, by HCE. HDL was significantly increased by HCD (0.6 to 1.6 mmol/L), but it was not affected by HCE administration. Furthermore, HCE suppressed HCD-induced liver oxidative stress, fibrosis, and lipid accumulation almost to control levels. Interestingly, HCE significantly increased the protein level of cholesterol 7 alpha-hydroxylase (CYP7A1), the rate-limiting enzyme for bile acid synthesis, by 1.5-fold in the liver. The present data suggest that HCE could be a functional food ingredient that can suppress the occurrence of diet-induced hypercholesterolemia and NAFLD, possibly by increasing the expression of CYP7A1., (© 2021 Institute of Food Technologists®.)

The prevalence of chronic kidney disease (CKD) is increasing worldwide, and a close association between acute kidney injury (AKI) and CKD has recently been identified. Black cumin ( Nigella sativa ) has been shown to be effective in treating various kidney diseases. Accumulating evidence shows that black cumin and its vital compound, thymoquinone (TQ), can protect against kidney injury caused by various xenobiotics, namely chemotherapeutic agents, heavy metals, pesticides, and other environmental chemicals. Black cumin can also protect the kidneys from ischemic shock. The mechanisms underlying the kidney protective potential of black cumin and TQ include antioxidation, anti-inflammation, anti-apoptosis, and antifibrosis which are manifested in their regulatory role in the antioxidant defense system, NF-κB signaling, caspase pathways, and TGF-β signaling. In clinical trials, black seed oil was shown to normalize blood and urine parameters and improve disease outcomes in advanced CKD patients. While black cumin and its products have shown promising kidney protective effects, information on nanoparticle-guided targeted delivery into kidney is still lacking. Moreover, the clinical evidence on this natural product is not sufficient to recommend it to CKD patients. This review provides insightful information on the pharmacological benefits of black cumin and TQ against kidney damage.

Aging is an unavoidable part of life. The more aged we become, the more susceptible we become to various complications and damages to the vital organs, including the kidneys. The existing drugs for kidney diseases are mostly of synthetic origins; thus, natural compounds with minimal side-effects have attracted growing interest from the scientific community and pharmaceutical companies. A literature search was carried out to collect published research information on the effects of resveratrol on kidney aging. Recently, resveratrol has emerged as a potential anti-aging agent. This versatile polyphenol exerts its anti-aging effects by intervening in various pathologies and multi-signaling systems, including sirtuin type 1, AMP-activated protein kinase, and nuclear factor-κB. Researchers are trying to figure out the detailed mechanisms and possible resveratrol-mediated interventions in divergent pathways at the molecular level. This review highlights (i) the causative factors implicated in kidney aging and the therapeutic aspects of resveratrol, and (ii) the effectiveness of resveratrol in delaying the aging process of the kidney while minimizing all possible side effects.

Acute kidney injury (AKI) most commonly appears in critically ill patients in hospitals. AKI is characterized as a quick deterioration of kidney function and has recently been identified to be tightly interlinked with chronic kidney diseases. The emerging major mediators of AKI include oxidative stress and endoplasmic reticulum (ER) stress. Carbon monoxide (CO) attenuates oxidative stress and ER stress in various cells, while Fyn, a member of the Src kinase family, is activated by oxidative stress and contributes to ER stress in skeletal muscle. Considering these, the objective of the current research was to determine (i) the involvement of Fyn in ER stress-mediated AKI and (ii) the effect of CO-releasing molecule-2 (CORM2) on reactive oxygen species- (ROS-) Fyn-ER stress-mediated AKI. Pretreatment with CORM2 (30 mg/kg) efficiently inhibited LPS (30 mg/kg)-induced oxidative stress, inflammation, and cellular apoptosis during AKI in C57BL/6J mice. Also, CORM2 efficiently suppressed the activation of Fyn and ER stress in AKI mice. Consistently, pretreatment with CORM2 inhibited oxidative stress, Fyn activation, ER stress, inflammation, and apoptosis in LPS- or H 2 O 2 -stimulated proximal epithelial tubular cells. Fyn inhibition using siRNA or an inhibitor (PP2) significantly attenuated ER stress responses in the cells. These data suggest that CORM2 may become a potential treatment option against ROS-Fyn-ER stress-mediated AKI., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2021 Md Jamal Uddin et al.)

Kidney fibrosis is the final outcome of chronic kidney disease (CKD). Adenosine plays a significant role in protection against cellular damage by activating four subtypes of adenosine receptors (ARs), A 1 AR, A 2A AR, A 2B AR, and A 3 AR. A 2A AR agonists protect against inflammation, and A 3 AR antagonists effectively inhibit the formation of fibrosis. Here, we showed for the first time that LJ-4459, a newly synthesized dual-acting ligand that is an A 2A AR agonist and an A 3 AR antagonist, prevents the progression of tubulointerstitial fibrosis. Unilateral ureteral obstruction (UUO) surgery was performed on 6-week-old male C57BL/6 mice. LJ-4459 (1 and 10 mg/kg) was orally administered for 7 days, started at 1 day before UUO surgery. Pretreatment with LJ-4459 improved kidney morphology and prevented the progression of tubular injury as shown by decreases in urinary kidney injury molecular-1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL) excretion. Obstruction-induced tubulointerstitial fibrosis was attenuated by LJ-4459, as shown by a decrease in fibrotic protein expression in the kidney. LJ-4459 also inhibited inflammation and oxidative stress in the obstructed kidney, with reduced macrophage infiltration, reduced levels of pro-inflammatory cytokines, as well as reduced levels of reactive oxygen species (ROS). These data demonstrate that LJ-4459 has potential as a therapeutic agent against the progression of tubulointerstitial fibrosis.

Alzheimer's disease (AD) is a degenerative brain disorder characterized by a progressive decline in memory and cognition, mostly affecting the elderly. Numerous functional bioactives have been reported in marine organisms, and anti-Alzheimer's agents derived from marine resources have gained attention as a promising approach to treat AD pathogenesis. Marine sterols have been investigated for several health benefits, including anti-cancer, anti-obesity, anti-diabetes, anti-aging, and anti-Alzheimer's activities, owing to their anti-inflammatory and antioxidant properties. Marine sterols interact with various proteins and enzymes participating via diverse cellular systems such as apoptosis, the antioxidant defense system, immune response, and cholesterol homeostasis. Here, we briefly overview the potential of marine sterols against the pathology of AD and provide an insight into their pharmacological mechanisms. We also highlight technological advances that may lead to the potential application of marine sterols in the prevention and therapy of AD.

Irisin is an exercise-induced myokine, suggested to exert beneficial effects on metabolism. However, the studies on the regulation of irisin secretion and the expression of its precursor FNDC5 have shown conflicting data. The discrepancies among previous correlation studies in humans are related to the heterogeneity of the study population. The fact that irisin is not only a myokine but also an adipokine leads to the further complexity of the role of irisin in metabolic regulation. In this study, we examined the regulation of FNDC5 expression and irisin in circulation in both type 1 and type 2 diabetic mice, and their potential relationships with metabolic parameters. In streptozotocin (STZ)-induced type 1 diabetic mice, high-fat diet (HFD)-induced obese mice and db/db mice, the circulating irisin as well as FNDC5 gene expression in subcutaneous fat was downregulated. Muscle FNDC5 expression was only significantly lower in STZ mice, and epididymal fat FNDC5 expression was unaltered. It is interesting to note that plasma irisin levels correlated positively with subcutaneous fat FNDC5 expression, but not epididymal fat or muscle. Moreover, both irisin levels and subcutaneous fat FNDC5 correlated negatively with markers of insulin resistance. These results suggest a regulatory role for subcutaneous fat-derived FNDC5/irisin in metabolic disease.

The global burden of chronic kidney disease (CKD) intertwined with cardiovascular disease has become a major health problem. Oxidative stress (OS) plays an important role in the pathophysiology of CKD. The nuclear factor erythroid 2-related factor 2 (Nrf2)-antioxidant responsive element (ARE) antioxidant system plays a critical role in kidney protection by regulating antioxidants during OS. Heme oxygenase-1 (HO-1), one of the targets of Nrf2-ARE, plays an important role in regulating OS and is protective in a variety of human and animal models of kidney disease. Thus, activation of Nrf2-HO-1 signaling may offer a potential approach to the design of novel therapeutic agents for kidney diseases. In this review, we have discussed the association between OS and the pathogenesis of CKD. We propose Nrf2-HO-1 signaling-mediated cell survival systems be explored as pharmacological targets for the treatment of CKD and have reviewed the literature on the beneficial effects of small molecule natural products that may provide protection against CKD.

Downstream mechanisms that lead to podocyte injury following phospholipase A2 receptor (PLA2R) autoimmunity remain elusive. To help define this we compared urinary metabolomic profiles of patients with PLA2R-associated membranous nephropathy (MN) at the time of kidney biopsy with those of patients with minimal change disease (MCD) and to healthy individuals. Among the metabolites differentially expressed in patients with PLA2R-associated MN compared to healthy individuals, fumarate was the only significant differentially expressed metabolite in PLA2R-associated MN compared to MCD [fold-difference vs. healthy controls and vs. MCD: 1.76 and 1.60, respectively]. High urinary fumarate levels could predict the composite outcome of PLA2R-associated MN. Fumarate hydratase, which hydrolyzes fumarate, colocalized with podocalyxin, and its expression was lower in glomerular sections from patients with PLA2R-associated MN than in those from healthy individuals, patients with non-PLA2R-associated MN or MCD. Podocytes stimulated with IgG purified from serum with a high anti-PLA2R titer (MN-IgG) decreased expression of fumarate hydratase and increased fumarate levels. These changes were coupled to alterations in the expression of molecules involved in the phenotypic profile of podocytes (WT1, ZO-1, Snail, and fibronectin), an increase in albumin flux across the podocyte layer and the production of reactive oxygen species in podocytes. However, overexpression of fumarate hydratase ameliorated these alterations. Furthermore, knockdown of fumarate hydratase exhibited synergistic effects with MN-IgG treatment. Thus, fumarate may promote changes in the phenotypic profiles of podocytes after the development of PLA2R autoimmunity. These findings suggest that fumarate could serve as a potential target for the treatment of PLA2R-associated MN., (Copyright © 2020 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.)

Src family kinases (SFKs), an important group of non-receptor tyrosine kinases, are suggested to be excessively activated during various types of tissue fibrosis. The present study investigated the effect of KF-1607, an orally active and a newly synthesized Src kinase inhibitor (SKI) with proposed low toxicity, in preventing the progression of renal interstitial fibrosis. Unilateral ureteral obstruction (UUO) surgery was performed in 6-week-old male C57BL/6 mice to induce renal interstitial fibrosis. Either KF-1607 (30 mg/kg, oral gavage) or PP2 (2 mg/kg, intraperitoneal injection), a common experimental SKI, was administered to mice for seven days, started one day prior to surgery. UUO injury-induced SFK expression, including Src, Fyn, and Lyn kinase. SFK inhibition by KF-1607 prevented the progression of tubular injury in UUO mice, as indicated by decreases in albuminuria, urinary KIM-1 excretion, and kidney NGAL protein expression. Renal tubulointerstitial fibrosis was attenuated in response to KF-1607, as shown by decreases in α-SMA, collagen I and IV protein expression, along with reduced Masson's trichrome and collagen-I staining in kidneys. KF-1607 also inhibited inflammation in the UUO kidney, as exhibited by reductions in F4/80 positive-staining and protein expression of p-NFκB and ICAM. Importantly, the observed effects of KF-1607 were similar to those of PP2. A new pan Src kinase inhibitor, KF-1607, is a potential pharmaceutical agent to prevent the progression of renal interstitial fibrosis.

Beta 2 adrenergic receptor (β 2 -AR)-agonists, widely used as bronchodilators, have demonstrated wide-spectrum anti-inflammatory properties in both immune and non-immune cells in various tissues. Their anti-inflammatory properties are mediated primarily, but not exclusively, via activation of the canonical β 2 -AR signaling pathway (β 2 -AR/cAMP/PKA). As non-canonical β 2 -AR signaling also occurs, several inconsistent findings on the anti-inflammatory effect of β 2 -agonists are notably present. Increasing amounts of evidence have unveiled the alternative mechanisms of the β 2 -AR agonists in protecting the tissues against injuries, i.e., by augmenting mitochondria biogenesis and SIRT1 activity, and by attenuating fibrotic signaling. This review mainly covers the basic mechanisms of the anti-inflammatory effects of β 2 -AR activation along with its limitations. Specifically, we summarized the role of β 2 -AR signaling in regulating kidney function and in mediating the progression of acute and chronic kidney diseases. Given their versatile protective effects, β 2 -agonists can be a promising avenue in the treatment of kidney diseases.

Background: Sarcopenia progresses in chronic kidney disease (CKD) and is positively correlated with mortality in end-stage kidney disease patients. Circulating irisin, an exercise-induced myokine, gradually decreases during CKD stage progression. Irisin inhibits the progression of kidney fibrosis, which is the final common outcome of CKD. Our preliminary study with C2C12 cells showed that Dojuksan, a herbal decoction, increases the expression of PGC1α (a regulator of irisin) and FNDC5 (a precursor of irisin)., Hypothesis: Dojuksan may increase circulating irisin and prevent the progression of kidney fibrosis., Study Design and Methods: Unilateral ureteral obstruction (UUO) was performed on seven-week-old male C57BL/6 mice to induce kidney tubulointerstitial fibrosis. Dojuksan (50, 100, or 200 mg/kg/day) or losartan (1.5 mg/kg/day), a standard clinical treatment for CKD, was administered orally one day prior to surgery and continued for seven days thereafter. To determine the role of irisin released from muscles, TGFβ-stimulated murine proximal tubular epithelial cells (mProx24 cells) were treated with conditioned media (CM) from Dojuksan-treated C2C12 muscle cells transfected with FNDC5 siRNA., Results: UUO mice exhibited muscle wasting along with progressive kidney injury. Similar to losartan, Dojuksan ameliorated kidney inflammation and fibrosis in UUO mice. Dojuksan, but not losartan, increased plasma irisin concentration in UUO mice. Dojuksan significantly increased basal FNDC5 expression and inhibited TNFα-induced and indoxyl sulfate-induced FNDC5 down-regulation in C2C12 cells. The TGFβ-induced collagen I (COL1) up-regulation in mProx24 cells was effectively inhibited by CM from C2C12 cells after Dojuksan treatment. Moreover, irisin inhibited TGFβ-induced COL1 in mProx24 cells, which was not affected by CM from C2C12 cells transfected with FNDC5 siRNA., Conclusion: Dojuksan ameliorates kidney fibrosis through irisin-mediated muscle-kidney crosstalk, suggesting that Dojuksan may be used as an alternative therapeutic agent against CKD., (Copyright © 2020 Elsevier GmbH. All rights reserved.)

Diabetic kidney disease (DKD) is the leading cause of chronic kidney disease and end-stage kidney disease. Renin-angiotensin system inhibitors such as losartan are the predominant therapeutic options in clinical practice to treat DKD. Therefore, it is necessary to identify DKD-related metabolic profiles that are affected by losartan. To investigate the change in metabolism associated with the development of DKD, we performed global and targeted metabolic profiling using 800 MHz nuclear magnetic resonance spectroscopy of urine samples from streptozotocin-induced diabetic mice (DM) with or without losartan administration. A principal component analysis plot showed that the metabolic pattern in the losartan-treated diabetic mice returned from that in the DM group toward that in the control mice (CM). We found that 33 urinary metabolites were significantly changed in DM compared with CM, and the levels of 16 metabolites among them, namely, glucose, mannose, myo-inositol, pyruvate, fumarate, 2-hydroxyglutarate, isobutyrate, glycine, threonine, dimethylglycine, methyldantoin, isoleucine, leucine, acetylcarnitine, 3-hydroxy-3-methylglutarate, and taurine, shifted closer to the control level in response to losartan treatment. Pathway analysis revealed that these metabolites were associated with branched-chain amino acid degradation; taurine and hypotaurine metabolism; glycine, serine, and threonine metabolism; the tricarboxylic acid cycle; and galactose metabolism. Our results demonstrate that metabolomic analysis is a useful tool for identifying the metabolic pathways related to the development of DKD affected by losartan administration and may contribute to the discovery of new therapeutic agents for DKD.

Acute kidney injury (AKI), a critical syndrome characterized by a rapid decrease of kidney function, is a global health problem. Src family kinases (SFK) are proto-oncogenes that regulate diverse biological functions including mitochondrial function. Since mitochondrial dysfunction plays an important role in the development of AKI, and since unbalanced SFK activity causes mitochondrial dysfunction, the present study examined the role of SFK in AKI. Lipopolysaccharides (LPS) inhibited mitochondrial biogenesis and upregulated the expression of NGAL, a marker of tubular epithelial cell injury, in mouse proximal tubular epithelial (mProx) cells. These alterations were prevented by PP2, a pan SFK inhibitor. Importantly, PP2 pretreatment significantly ameliorated LPS-induced loss of kidney function and injury including inflammation and oxidative stress. The attenuation of LPS-induced AKI by PP2 was accompanied by the maintenance of mitochondrial biogenesis. LPS upregulated SFK, especially Fyn and Src, in mouse kidney as well as in mProx cells. These data suggest that Fyn and Src kinases are involved in the pathogenesis of LPS-induced AKI, and that inhibition of Fyn and Src kinases may have a potential therapeutic effect, possibly via improving mitochondrial biogenesis.

Acute kidney injury (AKI) is a common disease with a complex pathophysiology which significantly contributes to the development of chronic kidney disease and end stage kidney failure. Preventing AKI can consequently reduce mortality, morbidity, and healthcare burden. However, there are no effective drugs in use for either prevention or treatment of AKI. Developing therapeutic agents with pleiotropic effects covering multiple pathophysiological pathways are likely to be more effective in attenuating AKI. Fyn, a nonreceptor tyrosine kinase, has been acknowledged to integrate multiple injurious stimuli in the kidney. Limited studies have shown increased Fyn transcription level and activation under experimental AKI. Activated Fyn kinase propagates various downstream signaling pathways associated to the progression of AKI, such as oxidative stress, inflammation, endoplasmic reticulum stress, as well as autophagy dysfunction. The versatility of Fyn kinase in mediating various pathophysiological pathways suggests that its inhibition can be a potential strategy in attenuating AKI.

Low-dose irradiation (LDI) has recently been shown to have various beneficial effects on human health, such as on cellular metabolic activities, DNA repair, antioxidant activity, homeostasis potency, and immune activation. Although studies on the immunogenic effects of LDI are rapidly accumulating, clinical trials for cancer treatment are considered premature owing to the lack of available preclinical results and protocols. Here, we aim to investigate anti-tumor and anti-metastatic effects of whole-body LDI in several tumor-bearing mouse models. Mice were exposed to single or fractionated whole-body LDI prior to tumor transplantation, and tumor growth and metastatic potential were determined, along with analysis of immune cell populations and expression of epithelial-mesenchymal transition (EMT) markers. Whole-body fractionated-LDI decreased tumor development and lung metastasis not only by infiltration of CD4 + , CD8 + T-cells, and dendritic cells (DCs) but also by attenuating EMT. Moreover, a combination of whole-body LDI with localized high-dose radiation therapy reduced the non-irradiated abscopal tumor growth and increased infiltration of effector T cells and DCs. Therefore, whole-body LDI in combination with high-dose radiation therapy could be a potential therapeutic strategy for treating cancer.

Sterol regulatory-element binding proteins (SREBPs) are classical regulators of cellular lipid metabolism in the kidney and other tissues. SREBPs are currently recognized as versatile transcription factors involved in a myriad of cellular processes. Meanwhile, SREBPs have been recognized to mediate lipotoxicity, contributing to the progression of kidney diseases. SREBP1 has been shown to bind to the promoter region of TGFβ, a major pro-fibrotic signaling mechanism in the kidney. Conversely, TGFβ activates SREBP1 transcriptional activity suggesting a positive feedback loop of SREBP1 in TGFβ signaling. Public ChIP-seq data revealed numerous non-lipid transcriptional targets of SREBPs that plausibly play roles in progressive kidney disease and fibrosis. This review provides new insights into SREBP as a mediator of kidney fibrosis via lipid-independent pathways., (Copyright © 2020 Dorotea, Koya and Ha.)

Peroxisomes are essential organelles for maintaining the homeostasis of lipids and reactive oxygen species (ROS). While oxidative stress-induced endoplasmic reticulum (ER) stress plays an important role in nonalcoholic fatty liver disease (NAFLD), the role of peroxisomes in ROS-mediated ER stress in the development of NAFLD remains elusive. We investigated whether an impaired peroxisomal redox state accelerates NAFLD by activating ER stress by inhibiting catalase, an antioxidant expressed exclusively in peroxisomes. Wild-type (WT) and catalase knockout (CKO) mice were fed either a normal diet or a high-fat diet (HFD) for 11 weeks. HFD-induced phenotype changes and liver injury accompanied by ER stress and peroxisomal dysfunction were accelerated in CKO mice compared to WT mice. Interestingly, these changes were also significantly increased in CKO mice fed a normal diet. Inhibition of catalase by 3-aminotriazole in hepatocytes resulted in the following effects: (i) increased peroxisomal H 2 O 2 levels as measured by a peroxisome-targeted H 2 O 2 probe (HyPer-P); (ii) elevated intracellular ROS; (iii) decreased peroxisomal biogenesis; (iv) activated ER stress; (v) induced lipogenic genes and neutral lipid accumulation; and (vi) suppressed insulin signaling cascade associated with JNK activation. N-acetylcysteine or 4-phenylbutyric acid effectively prevented those alterations. These results suggest that a redox imbalance in peroxisomes perturbs cellular metabolism through the activation of ER stress in the liver., Competing Interests: Declaration of competing interest The authors have no conflicting financial interests., (Copyright © 2019. Published by Elsevier Inc.)

Aims: Peroxisome is a critical organelle for fatty acid oxidation (FAO) and metabolism of reactive oxygen species (ROS). Increased oxidative stress in adipose tissue contributes to the development of insulin resistance and metabolic syndrome in obesity. This study aimed to investigate the role of peroxisomal fitness in maintaining adipocyte function, which has been under-rated in the obesity research area. Results: Reduced peroxisomal gene expressions in white adipose tissue (WAT) of obese mice suggested a close correlation between peroxisomes and obesity. Peroxisomal biogenesis factor 5 siRNA increased cellular ROS and inflammatory mediators in 3T3-L1 adipocytes. On the contrary, hydrogen peroxide or tumor necrosis factor-α treatment significantly decreased biogenesis- and function-related peroxisomal proteins, suggesting a positive feedback loop of ROS/inflammation and peroxisomal dysfunction. Correspondingly, catalase (a major peroxisomal antioxidant)-knockout mice fed with high-fat diet (HFD) exhibited suppressed peroxisomal proteins along with increased oxidative stress and accelerated obesity. In response to fenofibrate (a peroxisomal proliferator) treatment, WAT of HFD-fed wild-type mice showed not only increases in peroxisomal biogenesis and FAO but also attenuated features of adipocyte dysfunction and obesity. However, these results were not observed in peroxisome proliferator-activated receptor-alpha null obese mice. Innovation: Impaired peroxisomal fitness enhanced oxidative stress and inflammation in adipocytes, which exacerbates obesity. Conclusion: Adipose tissue peroxisomal homeostasis plays an important role in attenuating the features of obesity, and it can be a potential therapeutic target of obesity.

Diabetic kidney disease (DKD) is the leading cause of end-stage kidney disease. Epidemiological studies have demonstrated that cigarette smoke or nicotine is a risk factor for the progression of chronic kidney injury. The present study analyzed the kidney toxicity of cigarette smoke in experimental rats with DKD. Experimental diabetes was induced in 7-week-old Sprague-Dawley rats by a single intraperitoneal injection of streptozotocin (60 mg kg -1 ). Four weeks after the induction of diabetes, rats were exposed to cigarette smoke (200 μg L -1 ), 4 h daily, and 5 days per week for 4 weeks. Cigarette smoke did not affect the levels of plasma glucose, hemoglobin A1c, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol or non-esterified fatty acids in both control and diabetic rats under the experimental conditions. Cigarette smoke, however, significantly increased diabetes-induced glomerular hypertrophy and urinary kidney injury molecule-1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL) excretion, suggesting exacerbation of diabetic kidney injury. Cigarette smoke promoted macrophage infiltration and fibrosis in the diabetic kidney. As expected, cigarette smoke increased oxidative stress in both control and diabetic rats. These data demonstrated that four weeks of exposure to cigarette smoke aggravated the progression of DKD in rats., (This journal is © The Royal Society of Chemistry 2019.)

Focal segmental glomerulosclerosis (FSGS) and minimal change disease (MCD) have similar initial histological findings; however, their prognoses are distinct. Therefore, it is of great importance to discriminate FSGS from MCD in the early phase of disease and predict clinical prognosis. A discovery set of 184 urine samples (61 healthy control, 80 MCD, and 43 FSGS) and a validation set of 61 urine samples (12 healthy control, 26 MCD, and 23 FSGS) were collected at the time of kidney biopsy. Metabolic profiles were examined using nuclear magnetic resonance spectroscopy. Of 70 urinary metabolites, myo-inositol was significantly higher in FSGS patients than in control patients (discovery set, 2.34-fold, P < 0.001; validation set, 2.35-fold, P = 0.008) and MCD patients (discovery set, 2.48-fold, P = 0.002; validation set, 1.69-fold, P = 0.042). Myo-inositol showed an inverse relationship with the initial estimated glomerular filtration rate (eGFR) and was associated with the plasma level of soluble urokinase-type plasminogen activator receptor in FSGS patients. Myo-inositol treatment ameliorated the decreased expression of ZO-1 and synaptopodin in an in vitro FSGS model, and as myo-inositol increased, myo-inositol oxygenase tissue expression decreased proportionally to eGFR. Furthermore, urinary myo-inositol exhibited an increase in the power to discriminate FSGS patients, and its addition could better predict the response to initial treatment. In conclusion, urinary myo-inositol may be an important indicator in the diagnosis and treatment of FSGS patients.

Aging is defined as changes in an organism over time. The proportion of the aged population is markedly increasing worldwide. The kidney, as an essential organ with a high energy requirement, is one of the most susceptible organs to aging. It is involved in glucose metabolism via gluconeogenesis, glucose filtration and reabsorption, and glucose utilization. Proximal tubular epithelial cells (PTECs) depend on lipid metabolism to meet the high demand for ATP. Recent studies have shown that aging-related kidney dysfunction is highly associated with metabolic changes in the kidney. Peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α), a transcriptional coactivator, plays a major role in the regulation of mitochondrial biogenesis, peroxisomal biogenesis, and glucose and lipid metabolism. PGC-1α is abundant in tissues, including kidney PTECs, which demand high energy. Many in vitro and in vivo studies have demonstrated that the activation of PGC-1α by genetic or pharmacological intervention prevents telomere shortening and aging-related changes in the skeletal muscle, heart, and brain. The activation of PGC-1α can also prevent kidney dysfunction in various kidney diseases. Therefore, a better understanding of the effect of PGC-1α activation in various organs on aging and kidney diseases may unveil a potential therapeutic strategy against kidney aging., (© 2019 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.)

Patients with diabetes mellitus (DM) often suffer from diverse skin disorders, which might be attributable to skin barrier dysfunction. To explore the role of lipid alterations in the epidermis in DM skin disorders, we quantitated 49 lipids (34 ceramides, 14 free fatty acids (FFAs), and cholesterol) in the skin epidermis, liver, and kidneys of db/db mice, a Type 2 DM model, using UPLC-MS/MS. The expression of genes involved in lipid synthesis was also evaluated. With the full establishment of hyperglycemia at the age of 20 weeks, remarkable lipid enrichment was noted in the skin of the db/db mice, especially at the epidermis and subcutaneous fat bed. Prominent increases in the ceramides and FFAs (＞3 fold) with short or medium chains (＜C26) occurred in the skin epidermis (16NS, 18NS, 24NS, 16NDS, 18NDS, 20NDS, 22NDS, 24NDS, C16:1FA, C18:2FA, and C18:1FA) and the liver (16NS, 18NS, 20NS, 24:1NS, 18NDS, 20NDS, 22NDS, C16:1FA, C18:2FA, C18:1FA), whereas those with very long chains were not affected. In the kidney, only slight increases (＜3 fold) were observed for 16NS, 18NS, 20NS, 26NDS, C26FA, and C22:1FA. Consistently, LXRα/β and PPARγ, nuclear receptors promoting lipid synthesis, lipid synthesis enzymes such as elongases 1, 4, and 6, and fatty acid synthase and stearoyl-CoA desaturase were highly expressed in the skin and livers of the db/db mice. Collectively, our study demonstrates an extensive alteration in the skin and systemic lipid profiles of db/db mice, which could contribute to the development of skin disorders in DM.

Truncated 4'-thionucleosides 1-4 and 4'-oxonucleosides 5-8 as potent and selective A 3 AR antagonists were synthesized from D-mannose and D-erythronic acid γ-lactone, respectively. These nucleosides were evaluated for their anti-fibrotic renoprotective activity in TGF-β1-treated murine proximal tubular (mProx) cells. Their antagonistic activities for A 3 AR were proportional to their inhibitory activities against TGF-β1-induced collagen I upregulation in mProx cells. This result suggests that the binding affinity of A 3 AR antagonists is closely correlated with their anti-fibrotic activity. Thus, A 3 AR antagonists might be novel therapeutic candidates for treating chronic kidney disease.

Ionizing radiation (IR) has been widely used in the treatment of cancer. Radiation-induced DNA damage triggers the DNA damage response (DDR), which can confer radioresistance and early local recurrence by activating DNA repair pathways. Since karyopherin-α2 (KPNA2), playing an important role in nucleocytoplasmic transport, was significantly increased by IR in our previous study, we aimed to determine the function of KPNA2 with regard to DDR. Exposure to radiation upregulated KPNA2 expression in human colorectal cancer HT29 and HCT116 cells and breast carcinoma MDA-MB-231 cells together with the increased expression of DNA repair protein BRCA1. The knockdown of KPNA2 effectively increased apoptotic cell death via inhibition of BRCA1 nuclear import following IR. Therefore, we propose that KPNA2 is a potential target for overcoming radioresistance via interruption to DDR.

Hydrogen peroxide (H 2 O 2 ) produced endogenously can cause mitochondrial dysfunction and metabolic complications in various cell types by inducing oxidative stress. In the liver, oxidative and endoplasmic reticulum (ER) stress affects the development of non-alcoholic fatty liver disease (NAFLD). Although a link between both stresses and fatty liver diseases has been suggested, few studies have investigated the involvement of catalase in fatty liver pathogenesis. We examined whether catalase is associated with NAFLD, using catalase knockout (CKO) mice and the catalase-deficient human hepatoma cell line HepG2. Hepatic morphology analysis revealed that the fat accumulation was more prominent in high-fat diet (HFD) CKO mice compared to that in age-matched wild-type (WT) mice, and lipid peroxidation and H 2 O 2 release were significantly elevated in CKO mice. Transmission electron micrographs indicated that the liver mitochondria from CKO mice tended to be more severely damaged than those in WT mice. Likewise, mitochondrial DNA copy number and cellular ATP concentrations were significantly lower in CKO mice. In fatty acid-treated HepG2 cells, knockdown of catalase accelerated cellular lipid accumulation and depressed mitochondrial biogenesis, which was recovered by co-treatment with N-acetyl cysteine or melatonin. This effect of antioxidant was also true in HFD-fed CKO mice, suppressing fatty liver development and improving hepatic mitochondrial function. Expression of ER stress marker proteins and hepatic fat deposition also increased in normal-diet, aged CKO mice compared to WT mice. These findings suggest that H 2 O 2 production may be an important event triggering NAFLD and that catalase may be an attractive therapeutic target for preventing NAFLD.

The prevalence of nonalcoholic fatty liver disease (NAFLD) has increased with the incidence of obesity; however, the underlying mechanisms are unknown. In this study, high-resolution metabolomics (HRM) along with transcriptomics were applied on animal models to draw a mechanistic insight of NAFLD. Wild type (WT) and catalase knockout (CKO) mice were fed with normal fat diet (NFD) or high fat diet (HFD) to identify the changes in metabolic and transcriptomic profiles caused by catalase gene deletion in correspondence with HFD. Integrated omics analysis revealed that cholic acid and 3β, 7α-dihydroxy-5-cholestenoate along with cyp7b1 gene involved in primary bile acid biosynthesis were strongly affected by HFD. The analysis also showed that CKO significantly changed all-trans-5,6-epoxy-retinoic acid or all-trans-4-hydroxy-retinoic acid and all-trans-4-oxo-retinoic acid along with cyp3a41b gene in retinol metabolism, and α/γ-linolenic acid, eicosapentaenoic acid and thromboxane A2 along with ptgs1 and tbxas1 genes in linolenic acid metabolism. Our results suggest that dysregulated primary bile acid biosynthesis may contribute to liver steatohepatitis, while up-regulated retinol metabolism and linolenic acid metabolism may have contributed to oxidative stress and inflammatory phenomena in our NAFLD model created using CKO mice fed with HFD.

Long-term peritoneal dialysis is associated with progressive fibrosis of the peritoneum. Epithelial-mesenchymal transition (EMT) of mesothelial cells is an important mechanism involved in peritoneal fibrosis, and TGF-β1 is considered central in this process. However, targeting currently known TGF-β1-associated pathways has not proven effective to date. Therefore, there are still gaps in understanding the mechanisms underlying TGF-β1-associated EMT and peritoneal fibrosis. We conducted network-based integrated analysis of transcriptomic and proteomic data to systemically characterize the molecular signature of TGF-β1-stimulated human peritoneal mesothelial cells (HPMCs). To increase the power of the data, multiple expression datasets of TGF-β1-stimulated human cells were employed, and extended based on a human functional gene network. Dense network sub-modules enriched with differentially expressed genes by TGF-β1 stimulation were prioritized and genes of interest were selected for functional analysis in HPMCs. Through integrated analysis, ECM constituents and oxidative stress-related genes were shown to be the top-ranked genes as expected. Among top-ranked sub-modules, TNFAIP6, ZC3H12A, and NNT were validated in HPMCs to be involved in regulation of E-cadherin, ZO-1, fibronectin, and αSMA expression. The present data shows the validity of network-based integrated analysis in discovery of novel players in TGF-β1-induced EMT in peritoneal mesothelial cells, which may serve as new prognostic markers and therapeutic targets for peritoneal dialysis patients.

Chronic kidney disease (CKD) has become epidemic worldwide. Mitochondrial reactive oxygen species (ROS)-induced oxidative stress is an important mediator of CKD, and Prx3 plays a critical role in maintenance of mitochondrial ROS. The present study examined the role of Prx3 in the context of fibrosis, a common feature of CKD, using Prx3 KO mice under obstructive and diabetic stress. Prx3 deficiency accelerated fibrosis and inflammation accompanied by mitochondrial oxidative stress in obstructed and diabetic kidneys as well as in proximal tubular epithelial (mProx) cells. In addition, Prx3 deficiency induced Raw264.7 macrophages activation, leading to upregulation of proinflammatory cytokines. Conditioned media from LPS-stimulated Prx3 deficient macrophages accelerated proinflammatory and profibrotic cytokines in mProx cells. Interestingly, Prx3 deficiency induced most inflammatory and fibrotic cytokines at basal condition in both tissues and cells. Taken together, these results demonstrate that Prx3 deficiency can accelerate CKD through interactions between macrophages and tubular epithelial cells., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Renal fibrosis is the final common pathway of various renal injuries and it leads to chronic kidney disease. Autophagy is a cellular process of degradation of damaged cytoplasmic components and regulates cell death and proliferation. Cellular response during unilateral ureteral obstruction (UUO) is tubular segment specific. Thus the role of autophagy on renal tubulointerstitial fibrosis (TIF) after UUO may be different according to segment of nephron. The role of autophagy during UUO remains unclear especially in distal tubules. In this study, we investigated the role of autophagy in distal tubules on renal TIF using conditional knockout mice in which Atg7 was genetically ablated specifically in distal tubular epithelial cell (TEC). In green fluorescent protein (GFP)-LC3 transgenic mice, GFP-LC3 puncta was highly expressed in distal tubular cells of the obstructed kidneys after UUO. Genetic deletion of Atg7 specifically in distal TEC increased renal tubulointerstial fibrosis and epithelial-mesenchymal transition-like phenotype change after UUO through Smad4-dependent transforming growth factor (TGF)-β pathway. Distal tubule-specific autophagy-deficient mice increased the accumulation of damaged mitochondria and SQSTM1/p62-positive aggregates in the obstructed kidney and resulted in increased expression of NLRP3 inflammasome, interleukin (IL) 1-β and caspase-1. Distal TEC-specific Atg7 deletion enhanced apoptosis of TECs after UUO. In summary, our data showed that autophagy in distal TEC plays a protective role in development of renal tubulointerstial fibrosis through regulating the expression of TGF-β an IL1-β after UUO.

Acute kidney injury (AKI), which is defined as a rapid decline of renal function, becomes common and recently recognized to be closely intertwined with chronic kidney diseases. Current treatment for AKI is largely supportive, and endoplasmic reticulum (ER) stress has emerged as a novel mediator of AKI. Since carbon monoxide attenuates ER stress, the objective of the present study aimed to determine the protective effect of carbon monoxide releasing molecule-2 (CORM2) on AKI associated with ER stress. Kidney injury was induced after LPS (15 mg/kg) treatment at 12 to 24 h in C57BL/6J mice. Pretreatment of CORM2 (30 mg/kg) effectively prevented LPS-induced oxidative stress and inflammation during AKI in mice. CORM2 treatment also effectively inhibited LPS-induced ER stress in AKI mice. In order to confirm effect of CO on the pathophysiological role of tubular epithelial cells in AKI, we used mProx24 cells. Pretreatment of CORM2 attenuated LPS-induced ER stress, oxidative stress, and inflammation in mProx24 cells. These data suggest that CO therapy may prevent ER stress-mediated AKI., Competing Interests: CONFLICTS OF INTEREST: The authors declare no conflicts of interest.

Diabetic kidney disease (DKD) involves various pathogenic processes during progression to end stage renal disease, and activated metabolic pathways might be changing based on major pathophysiologic mechanisms as DKD progresses. In this study, nuclear magnetic resonance spectroscopy (NMR)-based metabolic profiling was performed in db/db mice to suggest potential biomarkers for early detection and its progression. We compared concentrations of serum and urinary metabolites between db/m and db/db mice at 8 or 20 weeks of age and investigated whether changes between 8 and 20 weeks in each group were significant. The metabolic profiles demonstrated significantly increased urine levels of glucose and tricarboxylic acid cycle intermediates at both 8 and 20 weeks of age in db/db mice. These intermediates also exhibited strong positive associations with urinary albumin excretion, suggesting that they may be potential biomarkers for early diagnosis. On the contrary, branched chain amino acid and homocysteine-methionine metabolism were activated early in the disease, whereas ketone and fatty acid metabolism were significantly changed in the late phase of the disease. We demonstrated phase-specific alterations in metabolites during progression of DKD. This study provides insights into perturbed mechanisms during evolution of the disease and identifies potential novel biomarkers for DKD., (Copyright © 2018. Published by Elsevier Inc.)

Diabetic kidney disease (DKD) is the leading cause of end-stage kidney disease, and the current pharmacological treatment for DKD is limited to renin-angiotensin system (RAS) inhibitors. Adenosine is detectable in the kidney and is significantly elevated in response to cellular damage. While all 4 known subtypes of adenosine receptors, namely, A 1 AR, A 2a AR, A 2b AR, and A 3 AR, are expressed in the kidney, our previous study has demonstrated that a novel, orally active, species-independent, and selective A 3 AR antagonist, LJ-1888, ameliorates unilateral ureteral obstruction-induced tubulointerstitial fibrosis. The present study examined the protective effects of LJ-2698, which has higher affinity and selectivity for A 3 AR than LJ-1888, on DKD. In experiment I, dose-dependent effects of LJ-2698 were examined by orally administering 1.5, 5, or 10 mg/kg for 12 weeks to 8-week-old db/db mice. In experiment II, the effects of LJ-2698 (10 mg/kg) were compared to those of losartan (1.5 mg/kg), which is a standard treatment for patients with DKD. LJ-2698 effectively prevented kidney injuries such as albuminuria, glomerular hypertrophy, tubular injury, podocyte injury, fibrosis, inflammation, and oxidative stress in diabetic mice as much as losartan. In addition, inhibition of lipid accumulation along with increases in PGC1α, a master regulator of mitochondrial biogenesis, were demonstrated in diabetic mice treated with either LJ-2698 or losartan. These results suggest that LJ-2698, a selective A 3 AR antagonist, may become a novel therapeutic agent against DKD.

Background: NADPH oxidases (Nox) is a major enzyme system contributing to oxidative stress, which plays an important role in the pathogenesis of diabetic kidney disease (DKD). We have shown an elevation of renal Nox1, Nox2, and Nox4 in diabetic mice. APX-115, a pan-Nox inhibitor, attenuated the progression of DKD in mice. As the standard diabetic mice cannot fully mimic human DKD, the present study was aimed to show the dose-dependent effect and to provide a confirmatory evidence of APX-115 in attenuating DKD in diabetic rats., Method: Type 1 diabetes was induced by a single 60 mg/kg intraperitoneal injection of streptozotocin in Sprague-Dawley rats. 0.5, 5, or 30 mg APX-115/kg/day or losartan 1 mg/kg/day were administered orally to diabetic rats for 8 weeks., Results: APX-115 treatment showed an improvement in kidney function and tubular and podocyte -injury, as well as attenuation of inflammation, fibrosis, and oxidative stress as much as losartan, a comparative drug and mainstay treatment in DKD. Therapeutic effect of APX-115 was exhibited in a dose-dependent manner; a dose of 30 mg/kg displayed a superior efficacy., Conclusion: This finding verified the pre-clinical data of APX-115 in protecting against DKD, which is important to bring APX-115 toward the next stage of drug development., (© 2018 S. Karger AG, Basel.)

Although favorable immune responses to low-dose irradiation (LDI) have been observed in normal mice, i.e., a hormesis effect, little is known about the effects of LDI in infectious diseases. In this study, we examined the effects of LDI on mice with sepsis, a severe and often lethal hyperinflammatory response to bacteria. Female C57BL/6 mice were whole-body irradiated with 10cGy 48h before Escherichia coli infection, and survival, bacterial clearance, cytokines, and antioxidants were quantified. LDI pretreatment significantly increased survival from 46.7% in control mice to 75% in mice with sepsis. The bacterial burden was significantly lower in the blood, spleen, and kidney of LDI-treated mice than in those of control septic mice. The levels of pro-inflammatory cytokines, e.g., IL-1β and IL-6, as well as anti-inflammatory IL-10 were markedly reduced in pre-LDI septic mice. Nitric oxide production by peritoneal macrophages was also reduced in pre-LDI septic mice. Immune cells in the spleen increased and Nrf2 and HO-1 were induced in pre-LDI septic mice. LDI stimulates the immune response and minimizes lethality in septic mice via enhanced bacterial clearance and reduced initial proinflammatory responses., (Copyright © 2017 Elsevier Inc. All rights reserved.)

8-Hydroxy-2-deoxyguanosine (8-OHdG), a marker of oxidative DNA damage, has been recently shown to exert anti-inflammatory effects through inhibition of Rac1. Inflammation in adipose tissue is a hallmark of obesity-induced insulin resistance, but the therapeutic potential of 8-OHdG in treatment of metabolic diseases has not been fully elucidated. The aim of this study was to examine the effect of exogenously administered 8-OHdG on adipose tissue and whole body metabolism. In cultured adipocytes, 8-OHdG inhibited adipogenesis and reversed TNFα-induced insulin resistance. In high-fat diet (HFD)-induced obese mice, 8-OHdG administration blunted the rise in body weight and fat mass. The decrease in adipose tissue mass by 8-OHdG was due to reduced adipocyte hypertrophy through induction of adipose triglyceride lipase and inhibition of fatty acid synthase expression. 8-OHdG also inhibited the infiltration of macrophages, resulting in amelioration of adipose tissue inflammation and adipokine dysregulation. Moreover, 8-OHdG administration ameliorated adipocyte as well as systemic insulin sensitivity. Both in vivo and in vitro results showed that 8-OHdG induces AMPK activation and reduces JNK activation in adipocytes. In conclusion, our results show that orally administered 8-OHdG protects against HFD-induced metabolic disorders by regulating adipocyte metabolism., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Recent evidences showed that elevation of plasminogen activator inhibitor 1 (PAI-1) was responsible in mediating obesity-induced non-alcoholic fatty liver disease (NAFLD) and metabolic disorders. Here, we investigated the effect of TM5441, an oral PAI-1 inhibitor that lacks of bleeding risk, on high-fat diet (HFD)-induced NAFLD. HFD-fed C57BL/6J mice was daily treated with 20 mg/kg TM5441. To examine the preventive effect, 10-week-treatment was started along with initiation of HFD; alternatively, 4-week-treatment was started in mice with glucose intolerance in the interventional strategy. In vivo study showed that early and delayed treatment decreased hepatic steatosis. Particularly, early treatment prevented the progression of hepatic inflammation and fibrosis in HFD mice. Interestingly, both strategies abrogated hepatic insulin resistance and mitochondrial dysfunction, presented by enhanced p-Akt and p-GSK3β, reduced p-JNK signaling, along with p-AMPK and PGC-1α activation. Consistently, TM5441 treatment in the presence of either PAI-1 exposure or TNF-α stimulated-PAI-1 activity showed a restoration of mitochondrial biogenesis related genes expression on HepG2 cells. Thus, improvement of insulin sensitivity and mitochondrial function was imperative to partially explain the therapeutic effects of TM5441, a novel agent targeting HFD-induced NAFLD., Competing Interests: CONFLICTS OF INTEREST The authors have no conflicts of interest.

NADPH oxidase (Nox)-derived reactive oxygen species (ROS) are increasingly recognized as a key factor in inflammation and extracellular matrix accumulation in diabetic kidney disease. APX-115 (3-phenyl-1-(pyridin-2-yl)-4-propyl-1-5-hydroxypyrazol HCl) is a novel orally active pan-Nox inhibitor. The objective of this study was to compare the protective effect of APX-115 with a renin-angiotensin system inhibitor (losartan), the standard treatment against kidney injury in diabetic patients, on streptozotocin (STZ)-induced diabetic kidney injury. Diabetes was induced by intraperitoneal injection of STZ at 50 mg/kg/day for 5 days in C57BL/6J mice. APX-115 (60 mg/kg/day) or losartan (1.5 mg/kg/day) was administered orally to diabetic mice for 12 weeks. APX-115 effectively prevented kidney injury such as albuminuria, glomerular hypertrophy, tubular injury, podocyte injury, fibrosis, and inflammation as well as oxidative stress in diabetic mice, similar to losartan. In addition, both APX-115 and losartan treatment effectively inhibited mitochondrial and peroxisomal dysfunction associated with lipid accumulation. Our data suggest that APX-115, a pan-Nox inhibitor, may become a novel therapeutic agent against diabetic kidney disease by maintaining peroxisomal and mitochondrial fitness., Competing Interests: CONFLICTS OF INTEREST None of the authors except SHM and SJL declared any competing interest. SHM and SJL work at Aptabio Therapeutics Inc, Korea which develops APX-115.

Non-alcoholic fatty liver disease (NAFLD) has become the most prevalent liver disease in parallel with worldwide epidemic of obesity. Reactive oxygen species (ROS) contributes to the development and progression of NAFLD. Peroxisomes play an important role in fatty acid oxidation and ROS homeostasis, and catalase is an antioxidant exclusively expressed in peroxisome. The present study examined the role of endogenous catalase in early stage of NAFLD. 8-week-old male catalase knock-out (CKO) and age-matched C57BL/6J wild type (WT) mice were fed either a normal diet (ND: 18% of total calories from fat) or a high fat diet (HFD: 60% of total calories from fat) for 2 weeks. CKO mice gained body weight faster than WT mice at early period of HFD feeding. Plasma triglyceride and ALT, fasting plasma insulin, as well as liver lipid accumulation, inflammation (F4/80 staining), and oxidative stress (8-oxo-dG staining and nitrotyrosine level) were significantly increased in CKO but not in WT mice at 2 weeks of HFD feeding. While phosphorylation of Akt (Ser473) and PGC1α mRNA expression were decreased in both CKO and WT mice at HFD feeding, GSK3β phosphorylation and Cox4-il mRNA expression in the liver were decreased only in CKO-HF mice. Taken together, the present data demonstrated that endogenous catalase exerted beneficial effects in protecting liver injury including lipid accumulation and inflammation through maintaining liver redox balance from the early stage of HFD-induced metabolic stress., Competing Interests: CONFLICTS OF INTEREST: The authors declare no conflicts of interest.

Fenofibrate activates not only peroxisome proliferator-activated receptor-α (PPARα) but also adenosine monophosphate-activated protein kinase (AMPK). AMPK-mediated cellular responses protect kidney from high-fat diet (HFD)-induced injury, and autophagy resulting from AMPK activation has been regarded as a stress-response mechanism. Thus the present study examined the role of AMPK and autophagy in the renotherapeutic effects of fenofibrate. C57BL/6J mice were divided into three groups: normal diet (ND), HFD, and HFD + fenofibrate (HFD + FF). Fenofibrate was administered 4 wk after the initiation of the HFD when renal injury was initiated. Mouse proximal tubule cells (mProx24) were used to clarify the role of AMPK. Feeding mice with HFD for 12 wk induced insulin resistance and kidney injury such as albuminuria, glomerulosclerosis, tubular injury, and inflammation, which were effectively inhibited by fenofibrate. In addition, fenofibrate treatment resulted in the activation of renal AMPK, upregulation of fatty acid oxidation (FAO) enzymes and antioxidants, and induction of autophagy in the HFD mice. In mProx24 cells, fenofibrate activated AMPK in a concentration-dependent manner, upregulated FAO enzymes and antioxidants, and induced autophagy, all of which were inhibited by treatment of compound C, an AMPK inhibitor. Fenofibrate-induced autophagy was also significantly blocked by AMPKα1 siRNA but not by PPARα siRNA. Collectively, these results demonstrate that delayed treatment with fenofibrate has a therapeutic effect on HFD-induced kidney injury, at least in part, through the activation of AMPK and induction of subsequent downstream effectors: autophagy, FAO enzymes, and antioxidants., (Copyright © 2017 the American Physiological Society.)

Background and Purpose: Obesity is one of the most prevalent chronic diseases worldwide, and dysregulated adipocyte function plays an important role in obesity-associated metabolic disorder. The level of plasma plasminogen activator inhibitor-1 (PAI-1) is increased in obese subjects, and PAI-1 null mice show improved insulin sensitivity when subjected to high-fat and high-sucrose diet-induced metabolic stress, suggesting that a best-in-class PAI-1 inhibitor may become a novel therapeutic agent for obesity-associated metabolic syndrome. TM5441 is a novel orally active PAI-1 inhibitor that does not cause bleeding episodes. Hence, in the present study we examined the preventive effect of TM5441 on high-fat diet (HFD)-induced adipocyte dysfunction., Experimental Approach: Ten-week-old C57BL/6J mice were fed a normal diet (18% of total calories from fat) or HFD (60% of total calories from fat) for 10 weeks, and TM5441 (20 mg·kg(-1) oral gavage) was administered daily with the initiation of HFD., Key Results: TM5441 prevented HFD-induced body weight gain and systemic insulin resistance. TM5441 normalized HFD-induced dysregulated JNK and Akt phosphorylation, suggesting that it prevents the insulin resistance of adipocytes. TM5441 also attenuated the macrophage infiltration and increased expression of pro-inflammatory cytokines, such as inducible nitric oxide synthase, induced by the HFD. In addition, TM5441 prevented the HFD-induced down-regulation of genes involved in mitochondrial biogenesis and function, suggesting that it may prevent adipocyte inflammation and dysregulation by maintaining mitochondrial fitness., Conclusion and Implications: Our data suggest that TM5441 may become a novel therapeutic agent for obesity and obesity-related metabolic disorders., (© 2016 The British Pharmacological Society.)

Diabetic nephropathy is the leading cause of end-stage renal disease worldwide, but no effective therapeutic strategy is available. Because plasminogen activator inhibitor-1 (PAI-1) is increasingly recognized as a key factor in extracellular matrix (ECM) accumulation in diabetic nephropathy, this study examined the renoprotective effects of TM5275 and TM5441, two novel orally active PAI-1 inhibitors that do not trigger bleeding episodes, in streptozotocin (STZ)-induced diabetic mice. TM5275 (50 mg/kg) and TM5441 (10 mg/kg) were administered orally for 16 weeks to STZ-induced diabetic and age-matched control mice. Relative to the control mice, the diabetic mice showed significantly increased (p < 0.05) plasma glucose and creatinine levels, urinary albumin excretion, kidney-to-bodyweight ratios, glomerular volume, and fractional mesangial area. Markers of fibrosis and inflammation along with PAI-1 were also upregulated in the kidney of diabetic mice, and treatment with TM5275 and TM5441 effectively inhibited albuminuria, mesangial expansion, ECM accumulation, and macrophage infiltration in diabetic kidneys. Furthermore, in mouse proximal tubular epithelial (mProx24) cells, both TM5275 and TM5441 effectively inhibited PAI-1-induced mRNA expression of fibrosis and inflammation markers and also reversed PAI-1-induced inhibition of plasmin activity, which confirmed the efficacy of the TM compounds as PAI-1 inhibitors. These data suggest that TM compounds could be used to prevent diabetic kidney injury.

Macrophages are important components of adipose tissue inflammation, which results in metabolic diseases such as insulin resistance. Notably, obesity induces a proinflammatory phenotypic switch in adipose tissue macrophages, and oxidative stress facilitates this switch. Thus, we examined the role of endogenous catalase, a key regulator of oxidative stress, in the activity of adipose tissue macrophages in obese mice. Catalase knockout (CKO) exacerbated insulin resistance, amplified oxidative stress, and accelerated macrophage infiltration into epididymal white adipose tissue in mice on normal or high-fat diet. Interestingly, catalase deficiency also enhanced classical macrophage activation (M1) and inflammation but suppressed alternative activation (M2) regardless of diet. Similarly, pharmacological inhibition of catalase activity using 3-aminotriazole induced the same phenotypic switch and inflammatory response in RAW264.7 macrophages. Finally, the same phenotypic switch and inflammatory responses were observed in primary bone marrow-derived macrophages from CKO mice. Taken together, the data indicate that endogenous catalase regulates the polarization of adipose tissue macrophages and thereby inhibits inflammation and insulin resistance.