Expression of matrix metalloproteinases MMP-2 and MMP-9 is altered during nephrogenesis in fetuses from diabetic rats

Installation of the developing nephron in the fetal human kidney during advanced pregnancy

BACKGROUND

The kidneys of preterm and low birth weight babies reflect vulnerability, since several noxae can evoke the termination of nephron formation. This again leads to oligonephropathy with severe consequences for health in the later life. While the clinical parameters have been intensely investigated, only little is known about the initial traces left by the noxae. For the fetal human kidney, solely the lack of basophilic S-shaped bodies and the reduction in width of the nephrogenic zone were registered. It is not known in how far also the involved progenitor cells, the earlier nephron stages, the collecting duct (CD) ampullae, and the local interstitium are collaterally harmed.

AIM

The interstitium at the forming nephron is heterogeneously structured. Thereby, it fulfills quite different mastering and integrative tasks. Since data dealing with the installation of a nephron is not available, the microanatomical features were recorded.

RESULTS

The microscopic specimens show that the installation of the transient stages of nephron anlage is not synchronized. Instead, it is controlled within a nephrogenic compartment of the nephrogenic zone. It starts near the renal capsule by positioning the nephrogenic niche so that the nephrogenic progenitor cells face the epithelial progenitor cell at the tip of a CD ampulla. Then, the induced nephrogenic progenitor cells assimilate in the pretubular aggregate. While its medial part remains opposite the head of the CD ampulla, at its proximal end, the primitive renal vesicle is formed. Only a part of it separates to stick to the section border between the head and conus of the CD ampulla. This marks the link with the future connecting tubule at the distal pole of the extending renal vesicle. Meanwhile, the proximal pole is mounted next to the connecting tubule of an earlier developed nephron. The resulting two-point mounting serves a common elongation of the conus at the CD ampulla and the medial aspect of the comma-shaped body. In the S-shaped body, it supports to defoliate the arising glomerulus and to link it with the perforating radiate artery at its deep lateral aspect.

CONCLUSIONS

The investigation depicts that the installation is an interactive process between the stages of nephron anlage and its structural neighbors. A special meaning has the interjacent interstitium. It is vital for the positioning, shaping, and physiological integration. Due to its special location, this is mainly exposed to noxae.

Engineering Strategies to Move from Understanding to Steering Renal Tubulogenesis

Rebuilding the kidney in the context of tissue engineering offers a major challenge as the organ is structurally complex and has a high variety of specific functions. Recreation of kidney function is inherently connected to the formation of tubules since the functional subunit of the kidney, the nephron, is based on tubular structures. In vivo, tubulogenesis culminates in a perfectly shaped, patterned, and functional renal tubule via different morphogenic processes that depend on delicately orchestrated chemical, physical, and mechanical interactions between cells and between cells and their microenvironment. This review summarizes the current understanding of the role of the microenvironment in the morphogenic processes involved in in vivo renal tubulogenesis. We highlight the current state-of-the-art of renal tubular engineering and provide a view on the design elements that can be extracted from these studies. Next, we discuss how computational modeling can aid in specifying and identifying design parameters and provide directions on how these design parameters can be incorporated in biomaterials for the purpose of engineering renal tubulogenesis. Finally, we propose that a step-by-step reciprocal interaction between understanding and engineering is necessary to effectively guide renal tubulogenesis. Impact statement Tubular tissue engineering lies at the foundation of regenerating kidney tissue function, as the functional subunit of the kidney, the nephron, is based on tubular structures. Guiding renal tubulogenesis toward functional renal tubules requires in-depth knowledge of the developmental processes that lead to the formation of native tubules as well as engineering approaches to steer these processes. In this study, we review the role of the microenvironment in the developmental processes that lead to functional renal tubules and give directions how this knowledge can be harnessed for biomaterial-based tubular engineering using computational models.

Renoprotective effects of tropisetron through regulation of the TGF-β1, p53 and matrix metalloproteinases in streptozotocin-induced diabetic rats

Renal fibrosis is a major cause of renal failure in diabetic nephropathy. Tropisetron is an antagonist of the 5HT3 receptor that exhibits anti-fibrosis effects. The present research aimed to investigate the protected role of tropisetron against renal fibrosis of diabetic nephropathy and its molecular mechanisms. For this purpose, male Wistar rats were allocated into 5 groups of control, tropisetron, diabetes, tropisetron + diabetes, and glibenclamide + diabetes (n = 7). After induction of type 1 diabetes with a single injection of STZ, tropisetron (3 mg/kg) and glibenclamide (1 mg/kg) were given to the rats daily by intraperitoneal injection for 2 weeks. The obtained data revealed that the treatment of diabetic rats with tropisetron led to a significant decrease in the elevated blood glucose, serum cystatin c, and urinary total protein (UTP) level, indicating the improvement of the impaired kidney function. Moreover, the results of Masson's trichrome staining showed that fibrosis attenuated in the kidney of diabetic rats after tropisetron treatment. RT-PCR and Western blotting revealed that TGF-β1, the apoptotic mediator, and p53 were considerably declined in the kidney of diabetic rats in response to tropisetron treatment. Meanwhile, the expressions of matrix metalloproteinase-9 (MMP-9) and matrix metalloproteinase-2 (MMP-2) were increased. These notable effects were equipotent with glibenclamide, as a standard drug, suggesting that tropisetron can alleviate renal fibrosis in diabetic nephropathy. Our data indicate that tropisetron could improve kidney function and attenuate renal fibrosis through regulation of TGF-β1, p53, and expression of extracellular matrix metalloproteinases.

High glucose condition inhibits trophoblast proliferation, migration and invasion by downregulating placental growth factor expression

AIM

This study aimed to investigate the effect of high glucose (HG) level on the proliferation, migration and invasion of trophoblasts and determine the role of placental growth factor (PLGF) in the process.

METHODS

HTR8-S/Vneo was treated with different concentrations of d-glucose (0, 10, 15, 20, 25 and 30 μM) at different times (0, 6, 12 and 24 h). qRT-PCR and Western blot analyses were used to measure PLGF expression. The protein level of PLGF was measured by immunofluorescence. Cell proliferation was assessed with CCK-8 analysis. Wound healing and transwell assays were used to evaluate cell migration and invasion. Intercellular ROS was detected with DCFH-DA.

RESULTS

After d-glucose treatment, the viability decreased in 25 and 30 μM groups. The HG group (25 μM) showed inhibited cell migration and invasion ability. The mRNA and protein levels of PLGF decreased under HG condition. Elevated ROS production was also detected in the HG group. Knocked-down PLGF expression enhanced increased ROS production and decreased cell migration and invasion, which reverted to the original levels after PLGF was overexpressed.

CONCLUSION

High glucose treatment inhibited HTR8-S/Vneo viability, migration and invasion by downregulating PLGF expression.

Hyperglycemia-induced mouse trophoblast spreading is mediated by reactive oxygen species

During embryo implantation, the outer layer of the blastocyst interacts with the endometrium giving rise to the development of the trophoblast cell lineage. The cells in this lineage participate in the penetration of endometrium due to their motility and invasive properties. The mechanisms that regulate the differentiation and invasive ability of these cells are essential for the establishment and maintenance of an efficient exchange between maternal and fetal tissues during pregnancy. In this context, hyperglycemia can induce oxidative stress causing alterations in the placenta. This study evaluated the role of reactive oxygen species (ROS) in the actions of high glucose concentration (HG) on trophoblast spreading and the expression of extracellular proteases in cultured mouse conceptuses. Blastocysts from gestational day 4 (GD4) were cultured until GD7 in HAM-F10 medium and further treated for 48 hr with HG (25 mM glucose) from GD7 to GD9. This treatment induced larger trophoblast outgrowths and increased ROS concentration, which was associated with increased expression levels of urokinase-type plasminogen activator (PLAU), plasminogen activator inhibitor 1 (PAI-1), and matrix metalloproteinase 9 (MMP-9). These effects were prevented by treatment with the non-specific antioxidant N-acetylcysteine (NAC) or apocynin, an inhibitor of NADPH oxidase. Our data suggest that the HG-induced trophoblast spreading and the expression of PLAU, PAI-1, and MMP-9 were mediated by the production of ROS via NADPH oxidase activity. Our results shed light on placental alterations in gestational diabetes mellitus.

Maternal diabetes induces changes in the umbilical cord gene expression

INTRODUCTION

Since maternal diabetes may affect fetal development and the umbilical cord provides an extension of the fetal vasculature, we decided to investigate cords' biological responses to maternal diabetic milieu.

METHODS

Using microarray analysis, we determined the gene expression profiles in the umbilical cords of six neonates born to type 1 diabetic mothers and in six control cords. Umbilical cord tissue was collected immediately after elective cesarean section. Expression data were confirmed by real-time polymerase chain reaction (11 genes). Additionally, the same umbilical cords were analyzed histologically.

RESULTS

Two hundred eighty six genes were differentially expressed in the umbilical cords from diabetic pregnancies compared to the controls (fold change ±1.5 and P < 0.01). Maternal diabetes had a major effect on the expression of genes involved in vascular development (Bone morphogenetic protein 4, Delta-like 1, and Notch homolog 4), vessel wall integrity (Collagen type VIII alpha 1, Myocyte enhancer factor 2C, and Matrix metalloproteinase 2), and vascular function (Natriuretic peptide precursor B, Endothelin 1, Endothelin receptor B, Cyclooxygenase 1, and Phosphodiesterase 5A). Maternal diabetes was associated with thicker umbilical vein intima-media layers and larger umbilical vein and artery intima-media areas compared to the controls.

DISCUSSION

Maternal diabetic environment seems to alter umbilical cord expression of genes involved in the regulation of vascular development and function with simultaneous umbilical vessel muscle layer thickening. These alterations suggest vascular phenotypic modifications, which in turn may lead to long-term vascular consequences in various tissues in infants of diabetic mothers.

Effect of Shenkang granules on the progression of chronic renal failure in 5/6 nephrectomized rats

Shenkang granules (SKGs) are a Chinese herbal medicinal formula, consisting of rhubarb (Rheum palmatum L.), Salvia miltiorrhiza, milkvetch root [Astragalus membranaceus (Fisch.) Bunge] and safflower (Carthamus tinctorius L.). The aim of the present study was to investigate the effect of SKG on chronic renal failure (CRF) in 5/6 nephrectomized (5/6 Nx) rats. The rats were randomly divided into seven groups (n=10 per group) as follows: (i) 5/6 Nx (model group; 2.25 ml/kg/day normal saline); (ii) SKGL (low dose; 5/6 Nx treated with 2 g crude drug/kg/day SKG); (iii) SKGM (moderate dose; 5/6 Nx treated with 4 g crude drug/kg/day SKG); (iv) SKGH (high dose; 5/6 Nx treated with 8 g crude drug/kg/day SKG); (v) benazepril treatment group (5/6 Nx treated with 5 mg/kg/day benazepril); (vi) Shenkang injection (SKI) group (5/6 Nx with 13.3 ml/kg/day SKI); and (vii) sham-operated group (2.25 ml/kg/day normal saline). After 30 days, the levels of microalbumin, total protein, serum creatinine, blood urea nitrogen and serum lipid were found to be significantly decreased in the SKGL and SKGM rats, showing histological improvement compared with the untreated 5/6 Nx rats, as determined by hematoxylin and eosin, and Masson's trichrome staining. In addition, SKG was found to significantly improve the levels of glutathione peroxidase and reduce the damage caused by free radicals to the kidney tissues. Furthermore, SKG prevented the accumulation of extracellular matrix by decreasing the expression of collagen I and III and inhibiting the expression of matrix metalloproteinases-2 and -9 in the renal tissue, as determined by western blot analysis. SKG was also shown to decrease the concentrations of serum transforming growth factor-β₁, as determined by ELISA, and kidney angiotensin II, as determined using a radioimmunoassay kit. In conclusion, SKG was demonstrated to ameliorate renal injury in a 5/6 Nx rat model of CRF. Thus, SKG may exert a good therapeutic effect on CRF.

Renal echo-3D and microalbuminuria in children of diabetic mothers: a preliminary study

Maternal diabetes has assumed epidemic relevance in recent years and animal studies have provided some evidence that it may cause abnormalities in renal development and a reduction in nephron endowment in the offspring; however, human data are lacking. The renal cortex contains ∼95% of the glomeruli and its volume could be taken as a surrogate measure of glomerular number; based on this assumption, we measured renal cortex volume and in addition, microalbuminuria in a homogeneous sample of 42 children of diabetic (pregestational, n = 13, and gestational, n = 29) mothers, compared with 21 healthy children born of non-diabetic mothers. The offspring of diabetic mothers showed a significant reduction of renal cortex volume and higher albumin excretion compared with controls, possibly attributable to a reduction in the number of nephrons and the difference was statistically significant (P < 0.001). Although further studies on a larger sample are necessary, our preliminary findings suggest that maternal diabetes may affect renal development with sequelae later in life, requiring closer monitoring and follow-up. Furthermore, the importance of strict maternal diabetes management and control must be emphasized.

Raloxifene upregulated mesangial cell MMP-2 activity via ER-β through transcriptional regulation

Raloxifene, a second-generation selective estrogen receptor modulator, exerts estrogen-like effects in specific tissues. In this present study, we examined the effect of raloxifene on mesangial cell matrix metalloproteinase-2 (MMP-2) activity in streptozotocin-induced diabetic mice. Raloxifene increased the MMP-2 level in a dose-dependent and receptor-mediated manner. An antibody against estrogen receptor-β (ER-β) blocked the effect of raloxifene on MMP-2 expression, suggesting that the effect of raloxifene on MMP-2 activity was mediated by ER-β. In addition, the transcription factor AP-2, that plays an important role in MMP-2 gene transcription, was overexpressed under raloxifene simulation. The effect of MMP-2 was blocked by a selective inhibitor of the extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/MAPK) pathway, PD98059. Our results suggested that raloxifene-induced MMP-2 activity increases function through ERK/MAPK signaling via AP-2. In addition, we also found that the effect of raloxifene on MMP-2 expression was mediated via its binding to ER-β. However, at this stage of our investigation, (i) we could only show that both the binding to ER-β and the activation of the ERK/MAPK pathway impacted MMP-2 expression and (ii) we were unable to establish a relationship between ER-β binding and ERK/MAPK pathway activation.

Lumbrokinase attenuates diabetic nephropathy through regulating extracellular matrix degradation in Streptozotocin-induced diabetic rats

OBJECTIVE

The present study was undertaken to investigate the therapeutic effect and underlying mechanisms of lumbrokinase on diabetic nephropathy.

METHODS

Type I diabetes was induced in male Sprague-Dawley rats via intraperitoneal injection of Streptozotocin (STZ). Lumbrokinase was administered to the diabetic rats at a dose of 600,000 U/kg body weight by gavage. As a positive control, perindopril, an angiotensin-converting enzyme inhibitor (ACEI), was given to diabetic rats at a dose of 4 mg/kg body weight. Following 12 weeks treatment, we measured the creatinine clearance rate (Ccr), urinary albumin excretion (UAE) and kidney injury scores. In addition, the expression of collagen IV, MMP-2 and MMP-9 in renal tissue was evaluated.

RESULTS

The diabetic rats developed proteinuria, glomerulosclerosis, tubulointerstitial fibrosis and a marked increase of renal cortical collagen IV. In contrast, MMP-2 and MMP-9 were significantly reduced in the renal cortex of diabetic rats. Interestingly, lumbrokinase treatment markedly reduced the proteinuria and improved the glomerulosclerosis and tubulointerstitial fibrosis in diabetic rats. The induction of collagen IV and the down-regulation of MMP-2 and MMP-9 was significantly attenuated by lumbrokinase. All these beneficial effects of lumbrokinase were comparable to the ACEI group.

CONCLUSION

Lumbrokinase treatment attenuated diabetic nephropathy in rats, possibly through increasing the activity of MMPs and the subsequent degradation of extracellular matrix.

Overweight, hypertension and renal dysfunction in adulthood of neonatally overfed rats

Accelerated growth in early infancy has been associated with later cardiovascular and metabolic diseases. We investigated the influence of overnutrition during neonatal periods on the development of renal pathophysiological changes in adult offspring rats. Three or 10 male pups per mother were assigned to either the small litter (SL) or normal litter (NL) control groups during the first 21 days of life. The effects of early postnatal overnutrition on body weight, blood pressure and renal changes were determined at 3 and 6 months. Pups in the SL group weighed more than controls between 7 days and 6 months of age (P<.05). In the SL group, serum creatinine levels were higher at 3 and 6 months (P<.05), and at 6 months, blood pressure levels were higher than those of the controls (P<.05). The number of ED-1 positive macrophages in renal cortex and glomerulosclerosis index increased in the SL group at 3 and 6 months (P<.05). Additionally, cortical apoptotic cells increased in the SL group at 6 months (P<.05). Immunoblotting and immunohistochemistry showed that matrix metalloproteinase (MMP)-9 protein expressions decreased and tissue inhibitor of MMP-1, tumor necrosis factor-α, osteopontin and adiponectin expressions increased in the SL group at 3 months (P<.05). However, at 6 months, MMP-9 expression was elevated, and osteopontin expression remained elevated in the SL group (P<.05). Early postnatal overfeeding can lead to lasting overweight, hypertension and renal dysfunction and place a greater burden on the kidney.

The role of matrix metalloproteinases and their inhibitors in the development of renal fibrosis in the patients with diabetes mellitus

The accumulation of components of extracellular matrix in the glomerular and interstitial compartments of the kidneys is a characteristic feature of diabetic nephropathy. The leading role in the extracellular matrix catabolism is played by matrix metalloproteinases (MMP). The activity of these enzymes is regulated by a group of inhibitors including tissue metalloproteinase inhibitors, plasminogen activator inhibitor-1, etc. Both in vivo and in vitro studies have demonstrated that a reduction of MMP activities and/or an increase of expression of MMP tissue inhibitors in the glomerular and tubular cells result in the suppression of catabolism of the components of extracellular matrix under the hyperglycemic conditions. Both circulating and urinary MMP as well as their inhibitors are considered to be new potential markers of renal fibrosis associated with diabetes mellitus. It is concluded that the directed activation of MMP and neutralization of their inhibitors provide a promising tool for the treatment of diabetic nephropathy.

Renal function, renal volume, and blood pressure in infants with antecedent of antenatal steroids

Steroids have been used for more than 20 years in preterm infants to induce pulmonary maturity; however, some long-term effects have been reported, such as insulin resistance and elevation of blood pressure. The aim of our study was to compare renal volume, renal function, and blood pressure in infants between 12-36 months of age with and without antecedent of antenatal steroid treatment. This was a cross-sectional study comprised of three groups of infants (n = 30, respectively): preterm infants with and without antecedent of receiving antenatal steroids, respectively, and full-term infants. Blood pressure, renal volume, glomerular filtration rate, and tubular function were measured. Blood pressure and cystatin C levels and glomerular filtration rate were higher in both groups of preterm infants than in the control group (p < 0.01). However, no difference in any of the tested variables between the steroid and non-steroid group of preterm infants. Renal volume was similar in preterm and control infants. Based on these results, we conclude that prematurity independent of antenatal steroid use is associated with higher cystatin C and blood pressure levels and a higher glomerular filtration rate in infants between 12-36 months of age.

Postnatal early overnutrition dysregulates the intrarenal renin-angiotensin system and extracellular matrix-linked molecules in juvenile male rats

Overnutrition during the perinatal period has been associated with susceptibility to obesity and related comorbidities. We examined the effects of postnatal early overnutrition on the development of juvenile obesity and the associated renal pathophysiological changes. Three or 10 pups per mother from rat pup litters were assigned to either the overnutrition or control groups during the first 21 days of life. The effects of overfeeding were measured at 28 days. The smaller male litter pups were heavier than the controls between 4 and 28 days after birth (P<.05). By 28 days of age, the kidney weight per body weight ratio decreased in the small litter group (P<.05). Circulating leptin levels increased in the small litter rats (P<.05). Overnutrition had no effect on renal cell proliferation, apoptosis, macrophages and glomerulosclerosis. In the immunoblots and immunohistochemistry, renin and angiotensin II type (AT) 2 receptor expression increased in the overfed rats (P<.05). By contrast, the plasminogen activator inhibitor (PAI)-1 and matrix metalloproteinase (MMP)-9 expression decreased in the overnutrition group (P<.05). The AT 1 receptor, tissue inhibitor of MMP-1, monocyte chemoattractant protein-1, tumor necrosis factor-α, osteopontin and adiponectin expression was not changed. Our data showed that postnatal early overfeeding led to hyperleptinemia, juvenile obesity and the acquired reset of renal maturation. Up-regulation of renin and AT2 and down-regulation of PAI-1 and MMP-9 might contribute to abnormal programming of renal growth in rats exposed to postnatal early overnutrition.

Adverse consequences of accelerated neonatal growth: cardiovascular and renal issues

Epidemiological and experimental studies show that the risk of cardiovascular and metabolic diseases at adulthood is inversely related to the weight at birth. Although with less evidence, low birth weight has been suggested to increase the risk of chronic kidney disease (CKD). It is well established that the developmental programming of arterial hypertension and of renal disease involves in particular renal factors, especially nephron endowment, which is reduced in low birth weight and maternal diabetes situations. Experimental studies, especially in rodents, have demonstrated the long-term influence of postnatal nutrition and/or postnatal growth on cardiovascular, metabolic and renal functions, while human data are scarce on this issue. Vascular and renal diseases appear to have a "multihits" origin, with reduced nephron number the initial hit and rapid postnatal growth the second hit. This review addresses the current understanding of the role of the kidney, both as a mechanism and as a target, in the developmental origins of adult disease theory, with a particular focus on the long-term effects of postnatal growth and nutrition.

Animal models in diabetes and pregnancy

The worldwide increase in the incidence of diabetes, the increase in type 2 diabetes in women at reproductive ages, and the cross-generation of the intrauterine programming of type 2 diabetes are the bases for the growing interest in the use of experimental diabetic models in order to gain insight into the mechanisms of induction of developmental alterations in maternal diabetes. In this scenario, experimental models that present the most common features of diabetes in pregnancy are highly required. Several important aspects of human diabetic pregnancies such as the increased rates of spontaneous abortions, malformations, fetoplacental impairments, and offspring diseases in later life can be approached by using the appropriate animal models. The purpose of this review is to give a practical and critical guide into the most frequently used experimental models in diabetes and pregnancy, discuss their advantages and limitations, and describe the aspects of diabetes and pregnancy for which these models are thought to be adequate. This review provides a comprehensive view and an extensive analysis of the different models and phenotypes addressed in diabetic animals throughout pregnancy. The review includes an analysis of the surgical, chemical-induced, and genetic experimental models of diabetes and an evaluation of their use to analyze early pregnancy defects, induction of congenital malformations, placental and fetal alterations, and the intrauterine programming of metabolic diseases in the offspring's later life.

Genetic regulatory networks of nephrogenesis: deregulation of WT1 splicing by benzo(a)pyrene

Recent studies have identified AHR as a master regulator of Wilms' tumor suppressor gene (WT1) signaling in the developing kidney. Activation of AHR signaling by environmental chemical is associated with proteasome-mediated degradation of AHR protein, disruption of WT1 alternative splicing, and marked alterations in the regulation of genetic programs of developmental progression in the developing kidney. The complexity of genetic regulatory networks of nephrogenesis controlled by AHR-WT1 interactions will be discussed here with particular emphasis given to the biological and medical consequences that may result from deficits in nephrogenesis that compromise reserve capacity and renal function later in life. Understanding the impact of early-life environmental exposures to chemicals that disrupt AHR signaling can help minimize negative health consequences to pregnant women and their offspring.

Developmental programming and hypertension

PURPOSE OF REVIEW

There is a growing body of evidence linking adverse events or exposures during early life and adult-onset diseases. After important epidemiological studies from many parts of the world, research now focuses on mechanisms of organ dysfunction and on refining the understanding of the interaction between common elements of adverse perinatal conditions, such as nutrition, oxidants, and toxins exposures. This review will focus on advances in our comprehension of developmental programming of hypertension.

RECENT FINDINGS

Recent studies have unraveled important mechanisms of oligonephronia and impaired renal function, altered vascular function and structure as well as sympathetic regulation of the cardiovascular system. Furthermore, interactions between prenatal insults and postnatal conditions are the subject of intensive research. Prematurity vs. intrauterine growth restriction modulate differently programming of high blood pressure. Along with antenatal exposure to glucocorticoids and imbalanced nutrition, a critical role for perinatal oxidative stress is emerging.

SUMMARY

While the complexity of the interactions between antenatal and postnatal influences on adult blood pressure is increasingly recognized, the importance of postnatal life in (positively) modulating developmental programming offers the hope of a critical window of opportunity to reverse programming and prevent or reduce related adult-onset diseases.

Ethanol extracts of Rehmannia complex (Di Huang) containing no Corni fructus improve early diabetic nephropathy by combining suppression on the ET-ROS axis with modulate hypoglycemic effect in rats

AIM

Liuwei Dihuang (Rehmannia complex, RC) decoction, a classic prescription of Traditional Chinese Medicine (TCM), has been used in treating diabetic nephropathy (DN). Among the 6 crude medicines which contains Corni fructus is recognized as the active fraction for its effectiveness. We aimed to investigate, first, if without Corni fructus a modified RC could be still effective, second, if the ethanol extracts could be better than that of water extract and third, the beneficial effect is mainly stemmed from suppressing the endothelin (ET-1) pathway associated with a moderate hypoglycemic effect.

METHODS AND MATERIALS

Diabetes for 8 weeks was induced by a single dose of streptozotocin (STZ, 65 mg/kg, i.p.) in rats and treated with RC extracts in either 95%, 70% ethanol or water separately during 5-8th week. The efficacy of extracts was compared with aminoguanidine (AMG).

RESULTS

An increase in albumin and creatinine in 24h urine, blood urea nitrogen (BUN) was found in STZ rats. Oxidative stress was found in renal cortex in association with upregulated plasma ET-1 and mRNA of ETA, decreased MMP 2,9 (matrix matelloproteinases) and increased hydroxyproline.

CONCLUSIONS

The RC without Corni fructus was very effective in alleviating DN and ethanol extracts provided greater effects against water extracts. The efficacy in alleviating DN is attributed to normalizing the activated ET system, oxidative stress and MMP 2,9 in combination with a moderate hypoglycemic activity.