Role of TGF-β in chronic kidney disease: an integration of tubular,glomerular and vascular effects

Transforming growth factor beta (TGF-β) has been recognized as an important mediator in the genesis of chronic kidney diseases (CKD), which are characterized by the accumulation of extracellular matrix (ECM) components in the glomeruli (glomerular fibrosis, glomerulosclerosis) and the tubular interstitium (tubulointerstitial fibrosis). Glomerulosclerosis is a major cause of glomerular filtration rate reduction in CKD and all three major glomerular cell types (podocytes or visceral epithelial cells, mesangial cells and endothelial cells) participate in the fibrotic process. TGF-β induces (1) podocytopenia caused by podocyte apoptosis and detachment from the glomerular basement membrane; (2) mesangial expansion caused by mesangial cell hypertrophy, proliferation (and eventually apoptosis) and ECM synthesis; (3) endothelial to mesenchymal transition giving rise to glomerular myofibroblasts, a major source of ECM. TGF-β has been shown to mediate several key tubular pathological events during CKD progression, namely fibroblast proliferation, epithelial to mesenchymal transition, tubular and fibroblast ECM production and epithelial cell death leading to tubular cell deletion and interstitial fibrosis. In this review, we re-examine the mechanisms involved in glomerulosclerosis and tubulointerstitial fibrosis and the way that TGF-β participates in renal fibrosis, renal parenchyma degeneration and loss of function associated with CKD.     

Modulation of tissue transglutaminase in tubular epithelial cells alters extracellular matrix levels: A potential mechanism of tissue scarring

The up-regulation and trafficking of tissue transglutaminase (TG2) by tubular epithelial cells (TEC) has been implicated in the development of kidney scarring. TG2 catalyses the crosslinking of proteins via the formation of highly stable ε(γ-glutamyl) lysine bonds. We have proposed that TG2 may contribute to kidney scarring by accelerating extracellular matrix (ECM) deposition and by stabilising the ECM against proteolytic decay.To investigate this, we have studied ECM metabolism in Opossum kidney (OK) TEC induced to over-express TG2 by stable transfection and in tubular cells isolated from TG2 knockout mice.Increasing the expression of TG2 led to increased extracellular TG2 activity (p < 0.05), elevated ε(γ-glutamyl) lysine crosslinking in the ECM and higher levels of ECM collagen per cell by ³H-proline labelling. Immunofluorescence demonstrated that this was attributable to increased collagen III and IV levels. Higher TG2 levels were associated with an accelerated collagen deposition rate and a reduced ECM breakdown by matrix metalloproteinases (MMPs).In contrast, a lack of TG2 was associated with reduced ε(γ-glutamyl) lysine crosslinking in the ECM, causing reduced ECM collagen levels and lower ECM per cell.We report that TG2 contributes to ECM accumulation primarily by accelerating collagen deposition, but also by altering the susceptibility of the tubular ECM to decay. These findings support a role for TG2 in the expansion of the ECM associated with kidney scarring.     

A Novel Function of Thrombin-activatable Fibrinolysis Inhibitor during Rat Liver Regeneration and in Growth-promoted Hepatocytes in Primary Culture

Thrombin-activatable fibrinolysis inhibitor (TAFI) exhibits anti-fibrinolytic activity by removing C-terminal lysine residues from fibrin or plasminogen receptor proteins on the cellular surface, and plays an important role in the regulation of fibrinolysis. In this study, we examined the regulation of TAFI in hepatocytes during liver regeneration, and revealed its pivotal role in hepatocyte proliferation. In rat models, partial hepatectomy or carbon tetrachloride (CCl₄)-induced acute liver injury suppressed the levels of plasma TAFI activity and hepatic TAFI mRNA, whereas this operation markedly increased both the hepatic plasmin activity and the level of proliferating cell nuclear antigen. In primary cultures of rat hepatocytes, the TAFI mRNA level was decreased under growth-promoting culture conditions. Treatment of the hepatocytes with TAFI siRNA increased the amount of plasmin on the hepatocytes and promoted hepatocyte proliferation. We concluded that TAFI regulates plasmin activity through its enzymatic activity whereby it reduces the plasminogen-binding capacity of the hepatocytes. The TAFI gene expression is down-regulated in hepatocyte proliferation for producing a fibrinolytic microenvironment suitable for cell growth. This is the first report on the role of TAFI in the pericellular fibrinolysis necessary for cellular proliferation.Thrombin-activatable fibrinolysis inhibitor (TAFI)³ is a 60-kDa plasma glycoprotein secreted by hepatocytes as an inactive form. Activation of TAFI is known to be mediated by thrombin (1), thrombin-thrombomodulin complex (2), or plasmin (3). Activated TAFI down-regulates fibrinolysis by removing the plasminogen-anchoring structure from fibrin. This fibrin structure contains C-terminal lysine residues, to which plasminogen binds via its lysine-binding site (4). Thus, TAFI is thought to exhibit negative regulatory activity in the binding of plasminogen to fibrin or cell surfaces.It is well known that plasminogen on fibrin or a cell surface exerts its maximum activity there, because this binding is not only a prerequisite for plasminogen activators to convert plasminogen to plasmin efficiently, but also a guarantee for the plasmin to be protected from inactivation by specific inhibitors, such as α2-plasmin inhibitor (5). As such, plasminogen can fulfill its roles for both thrombolysis and pericellular proteolysis, when it is located on the surface (6).It has been reported that activation of plasminogen is observed at the early stage of liver regeneration in rats and that plasmin contributes to the priming of hepatocytes for proliferation through the reorganization of extracellular matrix (ECM) components (7). The impairment of liver regeneration and abnormalities in liver repair have been observed in plasminogen-deficient mice, when they have undergone partial hepatectomy (8, 9) or been treated with CCl₄ (10). We demonstrated that the plasminogen activator/plasmin system acts to enhance the formation of hepatocyte spheroids (11) and to promote the proliferation of hepatocytes in vitro (12). These results strongly suggest that plasmin(ogen) is a positive regulator for liver regeneration.Although the function of TAFI in fibrinolysis has been well investigated (13), its function, including the regulation of TAFI gene expression in pericellular fibrinolytic events, remains to be investigated. In studies using TAFI-deficient mice, it has been found that such mice develop normally, reach adulthood, and are fertile. No gross physical abnormalities are observed up to 24 months of age (14). On the other hand, abnormalities in the cutaneous wound healing with delayed skin closure due to the altered epithelial migration and colonic anastomosis with bleeding complications are observed in these TAFI-deficient mice (15). Regarding TAFI gene expression, there is a report by Boffa et al. (16) showing that the combination of interleukin-1 and interleukin-6, but neither alone, reduces the abundance of TAFI mRNA in cultured human hepatoma (HepG2) cells by decreasing the stability of the mRNA.In the present study, we investigated the roles of TAFI in liver regeneration. The gene expression of TAFI was found to be strictly controlled by factors responsible for hepatocyte growth such as growth factors or physical conditions. In other words, suppression of TAFI action enhanced the growth of hepatocytes by providing higher plasmin activity on their surfaces. We employed the RNA interference technique to clarify the substantial role of TAFI. In TAFI-silenced hepatocytes, plasmin activity on hepatocyte surface increased, and hepatocyte proliferation was enhanced proportionally. Thus we demonstrated for the first time that TAFI plays an important role in the proliferation of hepatocytes in vivo through its regulatory effect on the cell surface-bound plasmin.     

Plasmin-mediated activation and inactivation of thrombin-activatable fibrinolysis inhibitor

Activated thrombin-activatable fibrinolysis inhibitor (TAFIa) attenuates the fibrin cofactor function of tissue-type plasminogen activator-mediated plasmin formation and subsequently fibrin degradation. In the present study, we focused on the role of plasmin in the regulation of TAFIa activity. Upon incubation with plasmin, TAFIa activity was generated, which was unstable at 37 degrees C. Analysis of the cleavage pattern showed that TAFI was cleaved at Arg(92), releasing the activation peptide from the 35.8-kDa catalytic domain. The presence of the 35.8-kDa fragment paralleled the time course of generation and loss of TAFIa activity. This suggested that, in the presence of plasmin, TAFIa is probably inactivated by proteolysis rather than by conformational instability. TAFI was also cleaved at Arg(302), Lys(327), and Arg(330), resulting in a approximately 44.3-kDa fragment and several smaller fragments. The 44.3-kDa fragment is no longer activatable since it lacks part of the catalytic center. We concluded that plasmin can cleave at several sites in TAFI and that this contributes to the regulation of TAFI and TAFIa.     

Iron-Hepcidin Dysmetabolism,Anemia and Renal Hypoxia,Inflammation and Fibrosis in the Remnant Kidney Rat Model

Anemia is a common complication of chronic kidney disease (CKD) that develops early and its severity increases as renal function declines. It is mainly due to a reduced production of erythropoietin (EPO) by the kidneys; however, there are evidences that iron metabolism disturbances increase as CKD progresses. Our aim was to study the mechanisms underlying the development of anemia of CKD, as well as renal damage, in the remnant kidney rat model of CKD induced by 5/6 nephrectomy. This model of CKD presented a sustained degree of renal dysfunction, with mild and advanced glomerular and tubulointerstitial lesions. Anemia developed 3 weeks after nephrectomy and persisted throughout the protocol. The remnant kidney was still able to produce EPO and the liver showed an increased EPO gene expression. In spite of the increased EPO blood levels, anemia persisted and was linked to low serum iron and transferrin levels, while serum interleukin (IL)-6 and high sensitivity C-reactive protein (hs-CRP) levels showed the absence of systemic inflammation. The increased expression of duodenal ferroportin favours iron absorption; however, serum iron is reduced which might be due to iron leakage through advanced kidney lesions, as showed by tubular iron accumulation. Our data suggest that the persistence of anemia may result from disturbances in iron metabolism and by an altered activity/function of EPO as a result of kidney cell damage and a local inflammatory milieu, as showed by the increased gene expression of different inflammatory proteins in the remnant kidney. In addition, this anemia and the associated kidney hypoxia favour the development of fibrosis, angiogenesis and inflammation that may underlie a resistance to EPO stimuli and reduced iron availability. These findings might contribute to open new windows to identify putative therapeutic targets for this condition, as well as for recombinant human EPO (rHuEPO) resistance, which occurs in a considerable percentage of CKD patients.     

Oxygenated analogues of UK-396082 as inhibitors of activated thrombin activatable fibrinolysis inhibitor

A suitable inhibitor of activated thrombin activatable fibrinolysis inhibitor (TAFIa) has the potential to be a novel treatment for thrombosis. The TAFIa inhibitor UK-396082 (1) was used as a starting point to seek more potent analogues. With knowledge of encouraging human pharmacokinetics and toleration for the clinical candidate (1), the programme continued to seek structure–activity relationships (SAR) that could positively impact on both potency and half-life, and therefore the projected dose of any future nominated clinical agent. A series of oxygenated analogues based on compound 1 were prepared to evaluate changes in pharmacology, selectivity and pharmacokinetics.     

Extracellular matrix degradation by cultured mesangial cells: mediators and modulators

Decreased degradation of the glomerular extracellular matrix (ECM) is thought to contribute to the accumulation of glomerular ECM that occurs in diabetic nephropathy and other chronic renal diseases. Several lines of evidence indicate a key role for the plasminogen activator/plasminogen/plasmin system in glomerular ECM degradation. However, which of the two plasminogen activators (PAs) present in renal tissue, tissue plasminogen activator (tPA) or urokinase-type plasminogen activator (uPA), is responsible for plasmin generation and those factors that modulate the activity of this system remain unclear. This study utilized mesangial cells isolated from mice with gene deletions for tPA, uPA, and plasminogen activator inhibitor 1 (PAI-1) to further delineate the role of the PA/plasminogen/plasmin system in ECM accumulation. ECM degradation by uPA-null mesangial cells was not significantly different from controls (92% +/- 1%, n = 12). In contrast, ECM degradation by tPA-null mesangial cells was markedly reduced (-78 +/- 1%, n = 12, P < 0.05) compared with controls, whereas tPA/uPA double-null mesangial cells degraded virtually no ECM. Previous studies from this laboratory have established that transforming growth factor-beta1 (TGFbeta1) inhibits ECM degradation by cultured mesangial cells by increasing the production of PAI-1, the major physiological PA inhibitor. In keeping with this observation, TGFbeta1 (1 ng/ml) had no effect on ECM degradation by PAI-1-null MC. High glucose levels (30 mM) in the presence or absence of insulin (0.1 mM) caused a moderate increase in ECM degradation by normal human mesangial cells. In contrast, glycated albumin, whose concentration is known to increase in diabetes, produced a dose-dependent (0.2-0.5 mg/ml) inhibition of ECM degradation by normal human mesangial cells. Taken together, these results document the importance of tPA versus uPA in renal plasmin production and indicate that in contrast to elevated glucose, glycated albumin may contribute to ECM accumulation in diabetic nephropathy.     

Implementing Patch Clamp and Live Fluorescence Microscopy to Monitor Functional Properties of Freshly Isolated PKD Epithelium

Cyst initiation and expansion during polycystic kidney disease is a complex process characterized by abnormalities in tubular cell proliferation, luminal fluid accumulation and extracellular matrix formation. Activity of ion channels and intracellular calcium signaling are key physiologic parameters which determine functions of tubular epithelium. We developed a method suitable for real-time observation of ion channels activity with patch-clamp technique and registration of intracellular Ca²⁺ level in epithelial monolayers freshly isolated from renal cysts. PCK rats, a genetic model of autosomal recessive polycystic kidney disease (ARPKD), were used here for ex vivo analysis of ion channels and calcium flux. Described here is a detailed step-by-step procedure designed to isolate cystic monolayers and non-dilated tubules from PCK or normal Sprague Dawley (SD) rats, and monitor single channel activity and intracellular Ca²⁺ dynamics. This method does not require enzymatic processing and allows analysis in a native setting of freshly isolated epithelial monolayer. Moreover, this technique is very sensitive to intracellular calcium changes and generates high resolution images for precise measurements. Finally, isolated cystic epithelium can be further used for staining with antibodies or dyes, preparation of primary cultures and purification for various biochemical assays.     

PAI-1 in tissue fibrosis

Fibrosis is defined as a fibroproliferative or abnormal fibroblast activation-related disease. Deregulation of wound healing leads to hyperactivation of fibroblasts and excessive accumulation of extracellular matrix (ECM) proteins in the wound area, the pathological manifestation of fibrosis. The accumulation of excessive levels of collagen in the ECM depends on two factors: an increased rate of collagen synthesis and or decreased rate of collagen degradation by cellular proteolytic activities. The urokinase/tissue type plasminogen activator (uPA/tPA) and plasmin play significant roles in the cellular proteolytic degradation of ECM proteins and the maintenance of tissue homeostasis. The activities of uPA/tPA/plasmin and plasmin-dependent MMPs rely mostly on the activity of a potent inhibitor of uPA/tPA, plasminogen activator inhibitor-1 (PAI-1). Under normal physiologic conditions, PAI-1 controls the activities of uPA/tPA/plasmin/MMP proteolytic activities and thus maintains the tissue homeostasis. During wound healing, elevated levels of PAI-1 inhibit uPA/tPA/plasmin and plasmin-dependent MMP activities, and, thus, help expedite wound healing. In contrast to this scenario, under pathologic conditions, excessive PAI-1 contributes to excessive accumulation of collagen and other ECM protein in the wound area, and thus preserves scarring. While the level of PAI-1 is significantly elevated in fibrotic tissues, lack of PAI-1 protects different organs from fibrosis in response to injury-related profibrotic signals. Thus, PAI-1 is implicated in the pathology of fibrosis in different organs including the heart, lung, kidney, liver, and skin. Paradoxically, PAI-1 deficiency promotes spontaneous cardiac-selective fibrosis. In this review, we discuss the significance of PAI-1 in the pathogenesis of fibrosis in multiple organs.     

Effects and mechanism of miR-23b on glucose-mediated epithelial-to-mesenchymal transition in diabetic nephropathy

MicroRNAs (miRNAs) play important roles in epithelial-to-mesenchymal transition (EMT). Moreover, hyperglycaemia induces damage to renal tubular epithelial cells, which may lead to EMT in diabetic nephropathy. However, the effects of miRNAs on EMT in diabetic nephropathy are poorly understood. In the present study, we found that the level of microRNA-23b (miR-23b) was significantly decreased in high glucose (HG)-induced human kidney proximal tubular epithelial cells (HK2) and in kidney tissues of db/db mice. Overexpression of miR-23b attenuated HG-induced EMT, whereas knockdown of miR-23b induced normal glucose (NG)-mediated EMT in HK2 cells. Mechanistically, miR-23b suppressed EMT in diabetic nephropathy by targeting high mobility group A2 (HMGA2), thereby repressing PI3K-AKT signalling pathway activation. Additionally, HMGA2 knockdown or inhibition of the PI3K-AKT signalling pathway with LY294002 mimicked the effects of miR-23b overexpression on HG-mediated EMT, whereas HMGA2 overexpression or activation of the PI3K-AKT signalling pathway with BpV prevented the effects of miR-23b on HG-mediated EMT. We also confirmed that overexpression of miR-23b alleviated EMT, decreased the expression levels of EMT-related genes, ameliorated renal morphology, glycogen accumulation, fibrotic responses and improved renal functions in db/db mice. Taken together, we showed for the first time that miR-23b acts as a suppressor of EMT in diabetic nephropathy through repressing PI3K-AKT signalling pathway activation by targeting HMGA2, which maybe a potential therapeutic target for diabetes-induced renal dysfunction.     

Role of MicroRNA 1207-5P and Its Host Gene,the Long Non-Coding RNA Pvt1, as Mediators of Extracellular Matrix Accumulation in the Kidney: Implications for Diabetic Nephropathy

Diabetic nephropathy is the most common cause of chronic kidney failure and end-stage renal disease in the Western World. One of the major characteristics of this disease is the excessive accumulation of extracellular matrix (ECM) in the kidney glomeruli. While both environmental and genetic determinants are recognized for their role in the development of diabetic nephropathy, epigenetic factors, such as DNA methylation, long non-coding RNAs, and microRNAs, have also recently been found to underlie some of the biological mechanisms, including ECM accumulation, leading to the disease. We previously found that a long non-coding RNA, the plasmacytoma variant translocation 1 (PVT1), increases plasminogen activator inhibitor 1 (PAI-1) and transforming growth factor beta 1 (TGF-β1) in mesangial cells, the two main contributors to ECM accumulation in the glomeruli under hyperglycemic conditions, as well as fibronectin 1 (FN1), a major ECM component. Here, we report that miR-1207-5p, a PVT1-derived microRNA, is abundantly expressed in kidney cells, and is upregulated by glucose and TGF-β1. We also found that like PVT1, miR-1207-5p increases expression of TGF-β1, PAI-1, and FN1 but in a manner that is independent of its host gene. In addition, regulation of miR-1207-5p expression by glucose and TGFβ1 is independent of PVT1. These results provide evidence supporting important roles for miR-1207-5p and its host gene in the complex pathogenesis of diabetic nephropathy.     

Mutations in the substrate binding site of thrombin-activatable fibrinolysis inhibitor (TAFI) alter its substrate specificity

Thrombin-activable fibrinolysis inhibitor (TAFI) is a zymogen that inhibits the amplification of plasmin production when converted to its active form (TAFIa). TAFI is structurally very similar to pancreatic procarboxypeptidase B. TAFI also shares high homology in zinc binding and catalytic sites with the second basic carboxypeptidase present in plasma, carboxypeptidase N. We investigated the effects of altering residues involved in substrate specificity to understand how they contribute to the enzymatic differences between TAFI and carboxypeptidase N. We expressed wild type TAFI and binding site mutants in 293 cells. Recombinant proteins were purified and characterized for their activation and enzymatic activity as well as functional activity. Although the thrombin/thrombomodulin complex activated all the mutants, carboxypeptidase B activity of the activated mutants against hippuryl-arginine was reduced. Potato carboxypeptidase inhibitor inhibited the residual activity of the mutants. The functional activity of the mutants in a plasma clot lysis assay correlated with their chromogenic activity. The effect of the mutations on other substrates depended on the particular mutation, with some of the mutants possessing more activity against hippuryl-His-leucine than wild type TAFIa. Thus mutations in residues around the substrate binding site of TAFI resulted in altered C-terminal substrate specificity.     

Rapamycin ameliorates kidney fibrosis by inhibiting the activation of mTOR signaling in interstitial macrophages and myofibroblasts

Interstitial fibrosis is an inevitable outcome of all kinds of progressive chronic kidney disease (CKD). Emerging data indicate that rapamycin can ameliorate kidney fibrosis by reducing the interstitial infiltrates and accumulation of extra cellular matrix (ECM). However, the cellular mechanism that regulates those changes has not been well understood yet. In this study, we revealed the persistent activation of mammalian target of rapamycin (mTOR) signaling in the interstitial macrophages and myofibroblasts, but rarely in injured proximal epithelial cells, CD4+ T cells, neutrophils, or endothelial cells, during the development of kidney fibrosis. Administration of rapamycin to unilateral ureteral obstruction (UUO) mice significantly suppressed the immunoreactivity of mTOR signaling, which decreased the inflammatory responses and ECM accumulation in the obstructed kidneys. Isolated macrophages from rapamycin-treated obstructed kidneys presented less inflammatory activity than vehicle groups. In vitro study confirmed that rapamycin significantly inhibited the fibrogenic activation of cultured fibroblasts (NIH3T3 cells), which was induced by the stimulation of TGF-β(1). Further experiment revealed that rapamycin did not directly inhibit the fibrogenesis of HK2 cells with aristolochic acid treatment. Our findings clarified that rapamycin can ameliorate kidney fibrosis by blocking the mTOR signaling in interstitial macrophages and myofibroblasts.     

Each liver X receptor (LXR) type has a different purpose in different situations

LXRs, which are nuclear receptors, have 2 isoforms—LXRα and LXRβ. Generally, LXRα is expressed in the liver, kidney, and a limited number of other organs, whereas LXRβ is thought to be expressed ubiquitously. Nevertheless, no clear consensus has been reached on the role of each in kidney lipid metabolism.Many researchers have reported that lipids accumulate in renal tubular epithelial cells during nephrosis. The nephrosis model we used showed the presence of urinary protein 4 days after the induction of illness. Additionally, the model maintained high levels of urinary protein from day 7–14. Lipid accumulation was clearly verified at day 4 and extreme accumulation was observed at day 7. We observed increased expression of LXRα from an early stage of nephrosis. To explore the role of increased LXRα in diseased kidney in vitro, NRK52E, normal kidney tubular epithelial cells, were forced to overexpress LXRα. These cells showed significantly lower lipid accumulation than mock cells did. In contrast, LXRβ knockdown lead to increased lipid accumulation in mock cells, and constancy in overexpressing cells.In normal kidneys, LXRβ is expressed stably to control mainly the intracellular lipids. However, with increasing intracellular lipid accumulation, expression of LXRα and its downstream gene, ABCA1, was upregulated, followed by lipid excretion in an LXRα-dependent manner. This phenomenon strongly suggests the importance of LXRα in lipid metabolism in the diseased kidney.     

Effects of Z-FA.FMK on d-galactosamine/tumor necrosis factor-alpha-induced kidney injury and oxidative stress in mice

Background The aim of this investigation was to demonstrate that benzyloxicarbonyl-l-phenylalanyl-alanine-fluoromethylketone (Z-FA.FMK), which is a pharmacological inhibitor of cathepsin B, has protective role on the kidney injury that occurs together with liver injury. Methods BALB/c male mice used in this study were divided into four groups. The first group was given physiologic saline only, the second group was administered Z-FA.FMK alone, the third group received d-galactosamine and tumor necrosis factor-alpha (d-GalN/TNF-α), and the fourth group was given both d-GalN/TNF-α and Z-FA.FMK. One hour after administration of 8 mg/kg Z-FA.FMK by intravenous injection, d-GalN (700 mg/kg) and TNF-α (15 μg/kg) were given by intraperitoneal injection. Results In the group given d-GalN/TNF-α, the following results were found: severe degenerative morphological changes in the kidney tissue, a significant increase in the number of activated caspase-3-positive tubular epithelial cell, an insignificant increase in the number of proliferating cell nuclear antigen (PCNA)-positive tubular epithelial cell, a decrease in the kidney glutathione (GSH) levels, catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities, an increase in the kidney lipid peroxidation (LPO) levels, lactate dehydrogenase (LDH) activity, serum aspartate aminotransferase (AST), and alanine aminotransferase (ALT) activities, uric acid and urea levels. In contrast, in the group given d-GalN/TNF-α and Z-FA.FMK, a significant decrease in the d-GalN/TNF-α-induced degenerative changes, a decrease in the number of activated caspase-3-positive tubular epithelial cell, a insignificant decrease in the number of PCNA-positive tubular epithelial cell, an increase in the kidney GSH levels, CAT, SOD and GPx activities, a decrease in the kidney LPO levels, LDH activity, serum AST and ALT activities, uric acid and urea levels were determined. Conclusion These results suggest that pretreatment with Z-FA.FMK markedly lessens the degree of impairment seen in d-GalN/TNF-α-induced kidney injury, which occurred together with liver injury in mice.