Pre- or post-treatment with hepatocyte growth factor prevents glycerol-induced acute renal failure

Hepatocyte growth factor (HGF) is known to have beneficial effects against damage in various organs, including liver, kidney and lung, in disease models. Previously, we reported that repeated administration of HGF ameliorates renal dysfunction and histological alteration of glycerol-injected rats, an animal model for severe acute renal failure (ARF). In the present study, we investigated in more detail the efficacy of pre- and post-treatment of HGF in this model. ARF was induced by intramuscular injection of glycerol into the hind limbs of male Wistar rats. The efficacy of pre-treatment was studied by intravenous injection of HGF (1 mg/kg) or vehicle 1 and 18 hours prior to glycerol injection. Pre-treatment of HGF dramatically protected glycerol-induced ARF rats against death, and prevented deterioration of biochemical parameters for renal function. We also analyzed expression of heme oxygenase-1 (HO-1), a cytoprotective protein, in kidney of HGF-injected rats. Intravenous administration of HGF enhanced renal expression of HO-1 mRNA from 1 to 3 hours after injection. Next, as a post-treatment study, HGF (1 mg/kg/3 hours) with dopamine was infused into glycerol-induced ARF rats 7 hours after glycerol injection. Intravenous infusion of HGF after ARF onset also ameliorated renal biochemical parameters. These results indicate that pre-treatment of HGF can improve ARF, and induction of HO-1 expression in kidney may be a cause of the protective effect. In addition, post-treatment of HGF with dopamine was also effective against the establishment of ARF.     

Ameliorative effect of hepatocyte growth factor on glycerol-induced acute renal failure with acute tubular necrosis

BACKGROUND/AIMS: Hepatocyte growth factor (HGF), a multi-potent growth factor, is known to promote regeneration of damaged renal epithelial cells. Glycerol injection into rats induces severe acute renal failure (ARF) with ischemia and tubular necrosis, a model which shares many features with human ARF or rhabdomyolysis. We investigated the efficacy of HGF in this glycerol-induced ARF rat model. METHODS: ARF was induced by intramuscular injection of glycerol into the hind limbs of male Wistar rats. HGF (0.25 mg/kg/shot) or vehicle was administered intravenously 1 h before and 1, 3, 5, 8, 24 and 36 h after glycerol injection. Biochemical parameters for serum and urine were measured and histological analyses of the kidneys were performed. We also analyzed endogenous HGF expression and phosphorylation of c-Met/HGF receptor in the kidneys of glycerol-induced ARF rats. RESULTS: Glycerol treatment caused severe ARF which invariably led to death of the rats. Repeated administration of HGF protected rats from death caused by severe ARF. Histological analyses revealed that HGF treatment reduced necrosis of tubular cells in the renal cortex. Serum/urine biochemical parameters also showed that renal dysfunction was improved by HGF administration. Intravenous administration of HGF enhanced phosphorylation of the c-Met/HGF receptor and mitogen-activated protein kinase in the kidney. In the vehicle-treated group the renal endogenous HGF concentration decreased and there was no change in c-Met/HGF receptor phosphorylation. CONCLUSION: These results indicate that HGF effectively accelerated the recovery of renal function and improved survival in glycerol-induced ARF rats.     

Single injection of naked plasmid encoding hepatocyte growth factor prevents cell death and ameliorates acute renal failure in mice.

Hepatocyte growth factor (HGF) is a pleiotrophic factor that plays an important role in tissue repair and regeneration after injury. The expression of both HGF and its c-met receptor genes is rapidly upregulated after acute renal injury induced by folic acid. In this study, the role of exogenous HGF in preventing acute renal failure by systemic administration of naked plasmid containing human HGF cDNA driven under the cytomegalovirus promoter (pCMV-HGF) was examined in mice. Intravenous injection of pCMV-HGF plasmid produced substantial levels of human HGF protein in mouse kidneys. Simultaneous injection of HGF plasmid DNA significantly ameliorated renal dysfunctions and accelerated recovery from the acute injury induced by folic acid. Of interest, preadministration of HGF plasmid 24 h before folic acid injection dramatically protected renal epithelial cells from both apoptotic and necrotic death and preserved the structural and functional integrity of renal tubules. Expression of HGF transgene activated protein kinase B/Akt kinase and preserved prosurvival Bcl-xL protein expression in vivo. These results indicate that a single, intravenous injection of naked plasmid containing HGF gene not only promotes renal regeneration after injury but also protects tubular epithelial cells from the initial injury and cell death in the first place. These data suggest that HGF gene therapy may provide a new avenue for exploring a novel therapeutic strategy for clinical acute renal failure.     

Serum hepatocyte growth factor concentration in patients with various degrees of chronic renal failure

Summary: Serum hepatocyte growth factor (HGF) concentrations were measured in healthy volunteers, chronic renal failure patients without renal replacement therapy and haemodialysis patients. Serum HGF concentrations in healthy volunteers, chronic renal failure patients and haemodialysis patients were 0.18 ± 0.04 (s.d.), 0.28 ± 0.06 and 0.46 ± 0.22 ng/mL, respectively. Serum HGF concentration in chronic renal failure patients was significantly higher than that in healthy volunteers. Serum HGF concentration in haemodialysis patients was significantly higher than those in healthy volunteers and chronic renal failure patients. There was no regression of serum HGF concentration on age, sex, history of haemodialysis, prehaemodialysis serum creatinine concentration, and serum tumour necrosis factor (TNF)-α concentration. We conclude that chronic renal disease and haemodialysis therapy are contributing factors to an increased serum HGF concentration.     

Production of platelet-activating factor in patients with sepsis-associated acute renal failure.

BACKGROUND: Studies in experimental animals have suggested that platelet-activating factor (PAF) is a mediator of sepsis-associated acute renal failure (ARF). In the present study we have evaluated whether an increased concentration of PAF within circulation or urine of septic patients correlated with the worsening of renal function. METHODS: The concentration of PAF and selected cytokines (TNF, IL-1, IL-6, IL-8) was evaluated in blood and urine of 12 patients with septic shock and ARF for 4 consecutive days. RESULTS: The data obtained indicate that blood and urinary concentrations of PAF and of IL-1, IL-6 and IL-8 were significantly higher in septic patients than in controls subjects and in patients with chronic renal failure. The concentration of TNF was significantly increased only in urine. A significantly positive correlation was found among blood concentration of PAF and heart rate (r = 0.4193, P < 0.017), serum creatinine (r = 0.3671, P < 0.038), serum IL-6 (r = 0.5475, P < 0.005) and urine excretion of IL-8 (r = 0.3984, P < 0.044), whereas a negative correlation was present with the number of circulating platelets (r = -0.4285, P < 0.018). Moreover, a positive correlation among the concentration of PAF in urine and the serum concentration of IL-6 (r = 0.5654, P < 0.006) and urine excretion of IL-6 (r = 0.6589, P < 0.0008) and IL-8 (r = 0.6371, P < 0.0004) were found. CONCLUSIONS: These results demonstrate in humans during ARF associated with septic shock the production of PAF, a mediator that has been previously implicated in the pathogenesis of experimental endotoxin-induced shock and renal injury. The observation that blood and urinary concentrations of PAF correlated with some of the clinical and laboratory parameters related to the severity of ARF and sepsis suggests that PAF may contribute to the development of renal injury in septic patients.     

Neutrophil activation in acute renal failure and sepsis

Neutrophils are activated during sepsis. To find out whether granulocytes are further activated during hemodialysis with cellulosic and noncellulosic membranes, we compared the plasma levels of the main granulocyte components in patients with chronic uremia who were undergoing regular hemodialysis treatment and patients with acute renal failure with and without sepsis. During hemodialysis with cuprophane dialyzers, plasma-granulocyte elastase, in complex with alpha-proteinase inhibitor, and lactoferrin levels increased in patients who were undergoing regular hemodialysis treatment, but these levels increased further in patients with acute renal failure who did not have sepsis. Maximal neutrophil degranulation was observed in patients with acute renal failure and sepsis. There was only mild degranulation in all three groups during dialysis with dialyzers made of polysulfone. Our data demonstrate that neutrophil activation is increased in patients with acute renal failure, and it is increased further by superimposed sepsis. Cellulose-containing dialysis membranes introduce a further activation of neutrophils.     

Time course of growth factor expression in mercuric chloride acute renal failure

BACKGROUND.: Renal EGF expression decreases in varying models of acute renalfailure (ARF). We found previously that the loss of distal tubularEGF during gentamicin ARF is strongest in the cortex, whereproximal tubular injury was most severe. To gain more insightinto the mechanism underlying this apparent anatomical association,renal growth factor expression was investigated during mercuricchloride ARF, in which proximal tubular injury is most severein the outer stripe of the outer medulla (OSOM). METHODS.: Endogenous renal growth factor expression was investigated byRNA hybridization and by imrnunohistochemistry in a rat modelof mercuric chloride ARF. In addition we determined temporaland spatial profiles of tubular injury, cell proliferation,and mononuclear cell infiltration during the 3-week observationperiod. RESULTS.: Serum creatinine values were maximal 2 days after treatmentand were again normalized at day 6. Tubular injury was mostsevere in the PST and maximal at day 2. Cell proliferation wasalso highest in the PST and maximal at day 4. Three weeks aftertreatment, normal renal morphology was restored. Increased numbersof mononuclear cells appeared transiently in the renal interstitiumfrom day 1 on. Most of these cells were macrophages and T lymphocytes;macrophages surrounded preferentially the severely injured PSTin the OSOM. In analogy to gentamicin ARF, renal EGF and IGF-Igene expression were decreased early in the setting of mercuricchloride ARF. The decrease in distal tubular EGF staining wasmost pronounced in the OSOM, i.e. the anatomical area wheremercuric-chloride-induced proximal tubular injury was most severe. CONCLUSIONS.: Renal EGF and IGF-I gene expression decreases strongly duringmercuric chloride ARF. The spatial association between the initialdecrease of distal tubular EGF expression and the zone of majorproximal tubular injury could originate from metabolic alterationssecondary to oxygen starvation. A possible role of mononuclearcells remains to be determined.     

Insulin-like growth factor I administration in young rats with acute renal failure

The outcome of ischemic acute renal failure (IARF) is better in young than adult rats. Insulin-like growth factor I (IGF-I) treatment may increase mortality of adult rats with IARF, probably because of an exaggerated inflammatory response. We report the response to IGF-I therapy in young rats with IARF. Male rats, aged 28+/-1 days, with IARF were given subcutaneous IGF-I, 50 microg/100 g at 0, 8, and 16 h after reperfusion (IGF) or were untreated (ARF). Sham-operated rats were used as controls. At 2 and 7 days after ischemia, serum urea nitrogen and histological damage score, cell proliferation, apoptosis, neutrophil infiltration, and IGF-I receptor mRNA in kidneys were analyzed. The degree of renal failure, mortality rate, histological damage, cell proliferation, and neutrophil infiltration were not different between IGF-I and ARF rats. Hence, short-term IGF-I treatment did not modify the course of IARF in young rats.     

急性肝衰竭大鼠载肝细胞生长因子纳米粒子肝细胞移植后有丝分裂指数和Ki-67表达变化及意义

目的 探讨急性肝衰竭(ALF)大鼠载肝细胞生长因子(HGF)的聚乳酸-氧-羧甲基壳聚糖(PLA-O-CMC)纳米粒子肝细胞移植后有丝分裂指数和Ki-67抗原的表达变化及意义.方法 D-氨基半乳糖腹腔内注射制作大鼠ALF模型,48 h后分别将Ⅰ型胶原(Ⅰ组)、PLA-O-CMC纳米粒子(Ⅱ、Ⅳ组)、载HGF的PLA-O-CMC纳米粒子(Ⅲ组)培养的大鼠肝细胞(均为5×107个,5 ml)移植到ALF大鼠腹腔内.以每日静脉注射HGF 10μg/kg×7 d(Ⅳ组)、5 Ml RPMI 1640腹腔内注射(Ⅴ组)作为对照.观察其14 d存活率、血清及肝组织HGF浓度、肝组织病理及有丝分裂指数(MI)、Ki-67变化.结果移植后14 d Ⅰ～Ⅴ组ALF大鼠的存活率分别为50.00％、68.75％、81.25％、75.00％、18.75％.各纳米移植组高于V组.Ⅲ组3 d时肝组织HGF浓度最高,平均为5882.91 μG／L.Ⅲ组肝组织结构恢复更快,5 d时平均MI 10.20％0、7 d时平均MI 10.20‰、7 d时Ki-67平均标记指数16.8‰,均高于Ⅴ组.结论 应用载HGF的PLA-O-CMC纳米粒子培养的大鼠肝细胞腹腔内移植治疗ALF大鼠能促进肝再生相关抗原表达.

Abstract：

Objective To evaluate the change and significance of Ki-67 antigen expression follow ing hepatocyte transplantation using hepatocyte growth factor (HGF) loaded polylactic acid-O-carboxymethylchitosan (PLA-O-CMC) nanoparticles in rats with acute liver failure (ALF). Methods ALF models of rats were established by D-galactosamine intraperitoneal injection. Rat hepatocytes type Ⅰ collagen suspension (group Ⅰ ),rat hepatocytes co-cultured with PLA-O-CMC nanoparticles ( groups Ⅱ ,Ⅳ ) and rat hepatocytes co-cultured with HGF loaded PLA-O-CMC nanoparticles ( group Ⅱ ) (5 × 107 cells each group,5 ml) were transplanted into the abdominal cavity of SD rats at 48 h after D-Gal injection. Intravenous injection of HGF ( 10 μg/kg for 7 days) ( group Ⅳ ) and RPMI 1640 injection (group Ⅴ ) were used as the negative groups. The 14th-day survival rate of rats,pathological change and mitotic index of liver,Ki-67 antigen labeling index of ALF rat livers were observed. Results The 14th-day survival rate in groups Ⅰ -Ⅴ was 50.00％,68. 75％,81.25％,75.00％,18.75％,and that in nano-transplanted groups was higher than in group Ⅴ. At the 3rd day,the concentration of HGF in liver tissue of group Ⅲ,average 5882. 91 μg/L was the highest. The hepatic lobules structure in group Ⅲ recovered faster. The average mitotic index in group Ⅱ at the 5th day was 10. 20‰ and the average Ki-67 labeling index at the 7th day was 16. 8‰,which were all higher than in group Ⅴ. Conclusion Intraperitoneal transplantation of HGF loaded PLA-O-CMC nanoparticle-attached hepatocytes for treatment of ALF can promote the liver regenerationassociated antigen expression.     

Production and metabolic clearance of calcitriol in acute renal failure

Metabolic clearance rate (MCR) and production rate (PR) of calcitriol were studied three and seven days after ischemic acute tubular necrosis (ATN). Creatinine clearance was decreased three days after clamping the renal arteries (0.42 +/- 0.03 ml/min/100 g, N = 6 in ATN vs. 0.68 +/- 0.09, N = 7 in sham controls; P less than 0.001). Plasma concentrations (24.1 +/- 1.9 pg/ml) and PR of calcitriol (9.8 +/- 0.91 ng/kg/day) were significantly lower in ATN rats three days after ischemic insult when compared to sham control rats, respectively (76.6 +/- 7.3 pg/ml, and 29.6 +/- 3.3 ng/kg/day; both P less than 0.01). The MCRs of calcitriol were not different between ATN (0.28 +/- 0.02 ml/min/kg) and sham control rats (0.27 +/- 0.01). By the seventh day after ischemic injury, when creatinine clearance of ATN rats returned to normal, both the PR and plasma concentrations of calcitriol also returned to normal values in these animals. In order to assess the effect of uremia on calcitriol metabolism, MCR and PR of calcitriol were measured in rats with reinfusion of their urines for 24 hours. The PR of calcitriol was significantly decreased (9.42 +/- 1.21; vs. controls, 20.5 +/- 2.9 ng/kg/day, P less than 0.001) in uremic animals. Since decreased PR of calcitriol was also accompanied by decreased MCR of calcitriol, plasma concentrations of calcitriol of the uremic rats with intact kidneys remained within normal values. We conclude that the PR of calcitriol is decreased early in ATN rats. Although the MCR was not decreased in mild ATN rats, it may decrease in severe acute renal failure.     

Serum hepatocyte growth factor levels in patients with renal diseases.

The serum levels of hepatocyte growth factor (HGF) were determined in patients with various renal diseases. In patients with acute-phase acute renal failure (ARF) and chronic tubulointerstitial nephritis (chronic TIN), the serum HGF levels were 0.55 +/- 0.24 and 0.44 +/- 0.37 ng/ml (mean +/- SD), respectively, and were significantly higher than that in the control group (0.12 +/- 0.12 ng/ml). The serum HGF level tended to be high also in patients with active-phase steroid-sensitive nephrotic syndrome (SSNS). The serum levels of HGF were not elevated in patients with IgA nephropathy (IgAN), Henoch-Sch?nlein purpura nephritis (HSPN), membranoproliferative glomerulonephritis (MPGN), poststreptococcal acute glomerulonephritis (PSAGN), unilateral renal atrophy, unilateral nephrectomy, or proximal tubular dysfunction. These observations suggest that glomerular disorders cause no apparent elevation of the serum HGF level, and that elevation of the serum HGF level may be associated with tubulointerstitial damage in renal diseases.     

Reciprocal balance of hepatocyte growth factor and transforming growth factor-beta 1 in renal fibrosis in mice

BACKGROUND: Transforming growth factor-beta 1 (TGF-beta 1) plays a central role in the pathogenesis of renal fibrosis. In contrast, hepatocyte growth factor (HGF) may be an important molecule for tissue repair. As TGF-beta 1 is a suppressor molecule for HGF expression, we asked whether a decrease in HGF expression would be accompanied by an increase in TGF-beta 1 and whether the progression of renal fibrosis would be modulated. METHODS: We used the ICR strain-derived glomerulonephritis (ICGN) mice as a model of chronic renal disease and examined changes in local HGF expression during the natural course of renal fibrosis. To determine the significance of intrinsic HGF noted during progression of renal fibrosis, we administered an anti-HGF antibody to mice at the early stage of renal fibrosis. RESULTS: At an early stage of renal fibrosis, the mice showed strong peritubular HGF expression, coinciding with tubular proliferation. In the late stages, the renal HGF level was markedly decreased, coinciding with a reduction in proliferative tubular areas. Renal TGF-beta 1 levels were increased in accordance with expansion of fibrotic areas. Notably, the anti-HGF antibody treatment of early-stage mice decreased the HGF level and reduced tubular areas, whereas collagen-deposited areas were expanded in parallel with increased TGF-beta 1 levels. Consequently, in HGF-neutralized mice, there was a rapid progression of renal dysfunction. CONCLUSIONS: Not only an increase in TGF-beta 1 level, but also a decrease in local HGF expression may be responsible for the manifestation of renal fibrosis, particularly tubular destruction.     

Evaluation of hepatocyte growth factor as a sensitive marker for early detection of acute renal allograft rejection

BACKGROUND: It has been shown that hepatocyte growth factor (HGF), besides its well-established hepatotrophic effect in liver regeneration, is involved in the regeneration of the kidney after injury. In the present study we investigated whether HGF can serve as a marker for detection of acute rejection in the early posttransplantation period. METHODS: HGF levels were determined in pre- and posttransplant sera (up to day 21) of 26 recipients with biopsy-proven acute rejection, 30 recipients with acute tubular necrosis (ATN), and 32 recipients without posttransplant complications. RESULTS: Although no association was found between pretransplant HGF and death-censored functional graft survival, receiver operating characteristic (ROC) curves demonstrated that HGF measured during the entire posttransplant study period, and especially on days 3 to 5, was a good marker for differentiating recipients who subsequently developed acute rejection from recipients with an uncomplicated course (P<0.0001, specificity 87%, sensitivity 84%). HGF measured from day 3 until day 21 posttransplantation, and especially on days 7 to 9, was also a sensitive marker for differentiating recipients with ATN from recipients with an uncomplicated course (P<0.0001). If considered in combination with sCD30, the diagnostic value of HGF was further improved. While 73% of samples from patients with impending rejection were positive for both HGF and sCD30, 94% of samples from nonrejecting patients were double-negative and none of the samples from this group fell into the double-positive category (P<0.0001). CONCLUSIONS: Our data suggest that HGF measured during the early posttransplant period might be a useful parameter for early detection of acute renal allograft rejection.     

Prevention of acute ischemic renal failure by targeted delivery of growth factors to the proximal tubule in transgenic mice: the efficacy of parathyroid hormone-related protein and hepatocyte growth factor

Treatment of acute renal failure (ARF) would be enhanced by identification of factors that accelerate renal recovery from injury. Parathyroid hormone-related protein (PTHrP) and hepatocyte growth factor (HGF) have been shown to stimulate proliferation in proximal nephron-derived cells. For studying the pathophysiologic roles and therapeutic potential of these two factors in ARF, transgenic mice overexpressing PTHrP or HGF in the proximal tubule under the direction of the gamma-glutamyl transpeptidase-I promoter were developed. These mice display (1) abundant expression of the respective transgenes in the kidney; (2) similar PTH type I receptor and HGF receptor (c-met) expression levels in the proximal tubule compared with control littermates; and (3) normal renal morphology, function, and tubule cell proliferation under basal conditions. However, in contrast to control mice, when acute ischemic renal injury was induced, renal function rapidly and dramatically recovered in HGF-overexpressing mice. In addition, 48 h after ischemia, HGF-overexpressing transgenic mice displayed a fourfold increase in tubule cell proliferation and a threefold decrease in apoptotic tubule cell death compared with control mice. In contrast, PTHrP-overexpressing mice responded to either ischemic or folic acid-induced renal damage similarly to control mice. These studies demonstrate that overexpression of PTHrP in the proximal nephron of mice does not seem to provide protection against acute renal injury. In marked contrast, HGF overexpression results in dramatic protection from ischemia-induced ARF, without inducing any apparent alteration in the physiology of the kidney under normal conditions. These studies suggest that HGF, when targeted specifically to the proximal tubule, may have therapeutic potential in providing protection against ischemia-induced renal failure.     

Potential role of platelet activating factor in acute renal failure

The clinical condition of acute renal failure (ARF) can be caused by a diverse number of renal injuries, but it is generally characterized by a sharp reduction in the glomerular filtration rate (GFR). A lipid mediator, platelet activating factor (PAF), may be one of the entities responsible for causing the hemodynamic changes in the ARF kidney because it can act as a vasodilator or vasoconstrictor, depending upon its concentration. This review examines the action and mechanisms of PAF in experimental animal models of ischemia and nephrotoxicity, as well as renal failure associated with extrarenal disease. While further research is necessary before extrapolating our current knowledge of PAF into the prevention of renal failure of therapeutic intervention using PAF antagonists in human ARF, there is reasonable evidence to support its role as a mediator of the decrease in GFR characteristic of ARF.     

Changes of urinary human epidermal growth factor excretion in 16 patients with acute renal failure]

In order to evaluate the clinical significance of urinary human epidermal growth factor (hEGF) in patients with acute renal failure (ARF), urinary hEGF levels were determined by radioimmunoassay, and were corrected for creatinine (creat.) concentrations in 16 patients with ARF and 12 healthy controls. The urinary hEGF levels significantly decreased in patients with ARF in acute phase compared with normal control subjects (0.98 +/- 0.20 vs 13.74 +/- 1.18 ng/mg creat. p less than 0.01), and it subsequently increased during recovery phase (6.10 +/- 0.73 ng/mg creat. p less than 0.01 vs acute phase). A significant correlation between the urinary hEGF levels and creatinine clearance (r = 0.712, p less than 0.001) and an inverse correlation between urinary hEGF levels and fractional excretion of sodium (r = -0.406, p less than 0.05) was demonstrated. The remarkable decrease of urinary hEGF excretion preceded the increase of urinary beta 2-microglobulin and N-acetyl-beta-D-glucosaminidase levels. Our data suggests that urinary hEGF originates from renal tissues in humans and measurement of urinary hEGF is useful for diagnosing renal damage and recovery of renal tissues from severe tubular injury.