Shenkang injection, a modern preparation of Chinese patent medicine, diminishes tubulointerstitial fibrosis in obstructive nephropathy via targeting pericyte-myofibroblast transition

Shenkang injection (SKI), a modern preparation of Chinese patent medicine, has been widely applied to clinical therapy in the chronic renal failure patients. However, it remains elusive whether SKI can ameliorate tubulointerstitial fibrosis (TIF) in vivo. Recently, pericyte-myofibroblast transition (PMT) plays an important role in the pathogenesis of TIF in obstructive nephropathy (ON). This report thus aims to demonstrate the therapeutic mechanisms of the dose-effects of SKI on TIF by targeting PMT and its signaling activation, compared with imatinib. All rats were divided into 5 groups, the sham-operated group, the vehicle-intervened group, the high dose of SKI-treated group, the low dose of SKI-treated group and the imatinib-treated group. The ON model rats were induced by unilateral ureteral obstruction (UUO), and administered with either the different doses of SKI or imatinib before and after modeling and for a period of 4 weeks. The changes before and after drugs intervention in TIF and PMT markers, and in platelet-derived growth factor receptor (PDGFR) and vascular endothelial growth factor receptor (VEGFR) signaling pathways activation in the kidneys were analyzed, respectively. As a result, PMT trigger was persistently accompanied with TIF exasperation in the obstructed kidneys after UUO, and that SKI definitely targeted PMT and significantly diminished TIF in vivo. In addition, the high dose of SKI, superior to imatinib, specifically blocked PMT through inhibiting the activation of PDGFR and VEGFR signaling in the kidneys of the UUO model rats. Overall, these findings may further suggest that targeting PMT can provide new strategies for ON treatment.

Huangkui capsule alleviates renal tubular epithelial-mesenchymal transition in diabetic nephropathy via inhibiting NLRP3 inflammasome activation and TLR4/NF-κB signaling

BACKGROUND

Huangkui capsule (HKC), an anti-inflammatory Chinese modern patent medicine, has been now widely applied to the clinical therapy of diabetic nephropathy (DN). However, the overall therapeutic mechanisms in vivo are still unclear. Renal tubular epithelial-to-mesenchymal transition (EMT) is one of the major pathogenesis of renal interstitial fibrosis in DN. Recently, the physiological roles of NLRP3 inflammasome activation and toll-like receptor 4 (TLR4)/nuclear factor (NF)-κB signaling are closely linked to EMT. But, it remains elusive whether HKC regulates renal tubular EMT in vivo through targeting NLRP3 inflammasome activation and TLR4/NF-κB signaling in the kidneys.

PURPOSE

This study thereby aimed to clarify the therapeutic effects of HKC on renal tubular EMT in DN and its underlying mechanisms in vivo, compared to rapamycin (RAP).

METHODS

Thirty-two rats were randomly divided into 4 groups: the Sham group, the Vehicle group, the HKC group and the RAP group. The early DN rat models were induced by unilateral nephrectomy combined with intraperitoneal injection of streptozotocin, and administered with HKC suspension or RAP suspension or vehicle after modeling for 4 weeks. Changes in the incipient renal lesions-related parameters in urine and blood were analyzed, respectively. Renal interstitial tissues were isolated for histomorphometry, immunohistochemistry and Western blotting at sacrifice.

RESULTS

For the early DN rat models, HKC at the suitable dose of 2 g/kg/day ameliorated the general condition and biochemical parameters partially including kidney weight (KW), urinary albumin (UAlb), serum creatinine (Scr) and serum albumin (Alb), attenuated renal tubular EMT significantly and inhibited the activation of NLRP3 inflammasome in the kidneys obviously, which was superior to RAP generally. In addition to these, HKC also suppressed TLR4/NF-κB signaling in the kidneys of the DN model rats accurately, which was different from RAP specifically.

CONCLUSION

The results of this study further indicated that HKC, different from RAP, can alleviate renal tubular EMT in the DN model rats, likely by inhibiting NLRP3 inflammasome activation and TLR4/NF-κB signaling in the kidneys. Our findings thus provide the more accurate information in vivo about a clinical value of HKC, a traditional anti-inflammatory phytomedicine, in the treatment of the early DN patients.

Hyperoside attenuates renal aging and injury induced by D-galactose via inhibiting AMPK-ULK1 signaling-mediated autophagy

The kidney is a typical organ undergoing age and injury. Hyperoside is reported to be useful for preventing aging induced by D-galactose (D-gal). However, therapeutic mechanisms remain unclear. We thereby aimed to verify whether hyperoside, compared to vitamin E (VE), could alleviate renal aging and injury by regulating autophagic activity and its related signaling pathways. In vivo, rats were administered with either hyperoside or VE after renal aging modeling induced by D-gal. Changes in renal aging and injury markers, autophagic activity and AMPK-ULK1 signaling pathway in the kidneys were analysed. In vitro, the NRK-52E cells exposed to D-gal were used to investigate regulative actions of hyperoside and VE on cell viability, renal tubular cellular aging markers, autophagic activity and its related signaling pathways by histomorphometry, immunohistochemistry, immunofluorescence, lentiviral transfection and Western blot. Aging and injury in the kidneys and renal tubular cells induced by D-gal were ameliorated by hyperoside and VE. Hyperoside and VE inhibited autophagic activity through mTOR-independent and AMPK-ULK1 signaling pathways. Hyperoside, as a component of phytomedicine similar to VE, attenuated renal aging and injury induced by D-gal via inhibiting AMPK-ULK1-mediated autophagy. This study provides the first evidence that hyperoside contributes to the prevention of age-associated renal injury.

[Regulative mechanisms of mammalian target of rapamycin signaling pathway in glomerular hypertrophy in diabetic nephropathy and interventional effects of Chinese herbal medicine]

Glomerular hypertrophy is the main pathological characteristic in the early stage of diabetic nephropathy (DN), and its regulatory mechanism is closely related to mammalian target of rapamycin (mTOR) signaling pathway activity. mTOR includes mTOR complex 1 (mTORC1) and mTOR complex 2(mTORC2), in which, the upstream pathway of mTORC1 is phosphatidylinositol-3-kinase (PI3K)/serine-threonine kinase(Akt)/adenosine monophosphate activated protein kinase(AMPK), and the representative signaling molecules in the downstream pathway of mTORC1 are 4E-binding proteins(4EBP) and phosphoprotein 70 S6Kinase(p70S6K). Some Chinese herbal extracts could improve cell proliferation via intervening the expressions of the key molecules in the upstream or downstream of PIK/Akt/mTOR signaling pathway in vivo. As for glomerular mesangial cells(MC) and podocyte, mTOR plays an important role in regulating glomerular inherent cells, including adjusting cell cycle, energy metabolism and matrix protein synthesis. Rapamycin, the inhibitor of mTOR, could suppress glomerular inherent cell hypertrophy, cell proliferation, glomerular basement membrane (GBM) thickening and mesangial matrix deposition in model rats with DN. Some Chinese herbal extracts could alleviate glomerular lesions by intervening mTOR signaling pathway activity in renal tissue of DN animal models or in renal inherent cells in vivo and in vitro.

[Effects and mechanisms of huangkui capsule ameliorating renal fibrosis in diabetic nephropathy rats via inhibiting oxidative stress and p38MAPK signaling pathway activity in kidney]

OBJECTIVE

To demonstrate the effects and mechanisms of Huangkui capsule (HKC) on renal fibrosis in rats with diabetic nephropathy (DN).

METHOD

Rats were randomly divided into 5 groups, the sham-operated group (Sham group, n = 5), the vehicle-given group (Vehicle group, n = 7), the low dose of HKC-treated group (L-HKC group, n = 7), the high dose of HKC-treated group (H-HKC group, n = 7) and the lipoic acid (LA)-treated group (LA group, n = 7). DN models were induced by intraperitoneal injection of streptozotocin (STZ,35 mg x kg(-1)) twice and unilateral nephrectomy. After models were successfully established, the rats in HKC and LA groups were daily administrated with HKC suspensions (0.75, 2 g x kg(-1)) or LA suspensions (60 mg x kg(-1)) respectively, and at the same time, the rats in Vehicle group were daily administrated with distilled water (2 mL) for 8 weeks. All rats were sacrificed at the end of week 8 to collect blood and renal tissues. UAlb, renal function, renal fibrotic morphologic characteristics, as well as oxidative stress (OS)-related markers, the protein expressions of the key signaling molecules in p38 mitogen-activated protein kinase (p38MAPK) signaling pathway, fibrogenic cytokines and inflammatory factors were examined respectively.

RESULT

HKC, similar to LA, improved the general state of health, body weight, UAlb, BUN, UA and Alb in DN model rats. Of note, renal fibrosis was ameliorated in HKC groups,especially in H-HKC group which was better than that in LA group. In addition, HKC not only improved the main indexes of OS in the kidney like LA, but also down-regulated the protein expressions of phosphorylated-p38MAPK (p-p38MAPK), transforming growth factor (TGF)-β1 and tumor necrosis factor(TNF)-α in the kidney, whereas, LA only decreased the protein expression of TNF-α in the kidney in DN model rats.

CONCLUSION

HKC, similar to LA, has the actions of anti-OS in vivo. Moreover, HKC could attenuate renal fibrosis by suppressing the activation of p38MAPK signaling pathway and the protein expressions of fibrogenic cytokines and inflammatory factors in the kidney in DN model rats, which is different from LA.

[Mechanisms of cordycepin on improving renal interstitial fibrosis via regulating eIF2α/TGF-β/Smad signaling pathway]

OBJECTIVE

To investigate the effects and mechanisms of cordycepin,an effective component of cordyceps militaris, on renal interstitial fibrosis (RIF) and its related eIF2α/TGF-β/Smad signaling pathway.

METHOD

Firstly, 15 C57BL/6 mice were randomly divided into 3 groups,the control group (Group A), the model group (Group B) and the cordycepin-treated group (Group C). After renal interstitial fibrotic model was successfully established by unilateral ureteral obstruction (UUO), the mice in Group C were intraperitoneally administrated with cordycepin(5 mg x kg(-1) d(-1)) and the ones in Group A and B were administrated with physiological saline for 5 days. At the end of the study, the obstructed kidneys were collected and detected for the pathological changes of RIF, and the mRNA expressions of collagen type I (Col I) and α-smooth muscle actin (α-SMA) in the kidney by Northern blot. Secondly, after renal tubular epithelial (NRK-52E) cells cultured in vitro were exposed to transforming growth factor (TGF) -β with or without cordycepin, the mRNA expressions of Col I and collagen type IV( Col IV) by Northern blot, and the protein expressions of eukaryotic initiation factor 2α (eIF2α), phosphorylated eIF2α ( p-eIF2α), Smad2/3 and phosphorylated Smad2/3 (p-Smad2/3) were tested by Western blot.

RESULT

In vivo, cordycepin alleviated RIF in model mice, including improving fibrotic pathological characteristics and mRNA expressions of Col I and α-SMA. In vitro, cordycepin induced the high expression of p-elF2α, and inhibited the expressions of p-Smad2/3, Col I and Col IV induced by TGF-β in NRK-52E cells.

CONCLUSION

Cordycepin attenuates RIF in vivo and in vitro, probably by inducing the phosphorylation of eIF2α, suppressing the expression of p-Smad2/3, a key signaling molecule in TGF-β/Smad signaling pathway, and reducing the expressions of collagens and α-SMA in the kidney.

[Effects and mechanisms of multi-glycoside of Tripterygium wilfordii improving glomerular inflammatory injury by regulating p38MAPK signaling activation in diabetic nephropathy rats]

OBJECTIVE

To explore the effects and mechanisms of multi-glycoside of Tripterygium wilfordii (GTW) on improving glomerular inflammatory lesion in rats with diabetic nephropathy (DN).

METHOD

DN model was induced by unilateral nephrectomy and intraperitoneal injection of STZ (35 mg x kg(-1)) twice. The rats were randomly divided into 3 groups, the sham-operated group (Sham group, n = 5), the vehicle-given group (Vehicle group, n = 5 ) and GTW-treated group (GTW group, n = 5). After the model was successfully established, the rats in GTW group were daily oral administrated with GTW suspension (50 mg x kg(-1) x d(-1)), meanwhile, the rats in Vehicle group were daily oral administrated with distilled water (2 mL) for 8 weeks. From the beginning of the administration, all rats were killed 8 weeks later. Blood and renal tissues were collected,and then UAlb, renal function, glomerular morphology characteristics and glomerular macrophages (ED1 + cells) infiltration, as well as the protein expressions of inflammatory cytokines including tumor necrosis factor(TNF)-α and interleukin(IL)-lβ, and the key molecules in p38MAPK signaling pathway including p38 mitogenactivated protein kinase (MAPK), phosphorylated p38 (p-p38MAPK) and transforming growth factor(TGF)-β1 were investigated respectively.

RESULT

GTW not only ameliorated the general state of health and body weight,but also attenuated UAlb, glomerulosclerosis, the infiltration of glomerular ED1 + cells and the protein expressions of TNF-α, IL-1β, p-p38MAPK and TGF-β1 in the kidney in DN model rats.

CONCLUSION

By means of DN model rats, we demonstrated that GTW has the protective effect on renal inflammatory damage in vivo via inhibiting inflammatory cells infiltration and inflammatory cytokines expression. Furthermore, GTW could improve renal inflammatory lesion through down-regulating the expressions of the key signaling molecules in p38MAPK pathway such as p-p38MAPK and TGF-β1 ,and inhibiting the activation of p38MAPK signaling in the kidney.

[Recognition of experimental animal model with kidney disease]

Animal models with kidney disease are generally divided into two types. One belongs to the models which imitate human kidney disease by the artificial operations, such as anti-glomerular basement membrane antibody nephritis, Heymann nephritis, anti-Thyl. 1 antibody nephritis, BSA nephritis and puromycin nephropathy. The other one pertains to the models which make themselves kidney disease, and appear the pathological characteristics naturally as like as human, such as HIGA mice with IgA nephropathy and NZB/WF1 and MRL/1pr mice with lupus nephritis. In addition,the transgenic animal models with kidney disease can also be established by the modern molecular biologic techniques including gene knockout and siRNA transfection. As for the studies related with kidney disease in pharmacodynamics and pharmacology of Chinese herbal medicine (CHM), it is important to understand deeply the features of each animal model with kidney disease, and select accurately the proper models according to the different experimental objectives, and then, build the special models provided with the combination of disease with syndrome in traditional Chinese medicine (TCM). Therefore,it is the developmental direction for the further study to establish animal models with kidney disease, which should possess the characteristics of syndrome in TCM.

[Effects of huangkui capsule on renal inflammatory injury by intervening p38MAPK signaling pathway in rats with adriamycin-induced nephropathy]

OBJECTIVE

To explore the potential mechanisms of huangkui capsule (HKC), an extract from Abelmoschus manihot (AM), for ameliorating renal inflammatory injury by regulating p38 mitogen-activated protein kinase (MAPK) signaling pathway in rats with adriamycin-induced nephropathy (ADRN).

METHOD

Nineteen Sprague-Dawley (SD) rats were randomly divided into three groups, the sham-operation group, the untreated model group,and the HKC-treated group. Rats in the untreated model group and the HKC-treated group were made into ADRN model by right nephrectomy and twice intravenous injections of adriamycin( ADR, 0.4 mL and 0.2 mL respectively within 4 weeks). After the model successfully established, rats in the HKC-treated group were orally given HKC (2 mg x kg(-1) per day), while rats in the untreated model group and the sham-operation group were intervened with distilled water respectively. The intervention for all rats was 4 weeks. Rats' body weight were weighted and 24 h urinary protein excretion (Upro) was detected at the end of the 1st, 2nd, 3rd, and 4th week after the intervention of HKC or distilled water. All rats were sacrificed at the end of the 8th week after nephrectomy, and then, to withdraw blood and kidney to examine the blood biochemical parameters, the glomerular morphological changes, alpha-smooth muscle actin (alpha-SMA) and collagen type I expressions,and the glomerular macrophages infiltration. Besides, the protein expression of transforming growth factor (TGF)-beta1, p38MAPK, as well as phosphorylated p38MAPK (p-p38MAPK) in renal tissues were detected by Western blotting.

RESULT

As compared with rats in the untreated model group, in the HKC-treated group,the HKC treatment significantly improved Upro, serum albumin, mesangial cell proliferation, extracellular matrix (ECM) and collagen deposition,and decreased the expression of alpha-SMA and collagen type I and the infiltration of ED1+ and ED3+ cells in glomeruli. In addition, it significantly down-regulated the protein expression of TGF-beta1 and p-p38MAPK in renal tissues.

CONCLUSION

HKC had the effects on ameliorating renal inflammatory injury in vivo. It could reduce the expression of TGF-beta1 and improve the infiltration and activation of inflammatory cells in glomeruli by way of intervening p38MAPK signaling pathway in kidney through down-regulating the protein expression of p-p38MAPK, as the key signal molecule.

NADPH oxidase-mediated upregulation of connexin43 contributes to podocyte injury

The gap junction protein connexin43 (Cx43) was markedly increased in podocytes in a rat model of nephrosis induced by puromycin. However, the mechanisms and roles of the altered Cx43 in podocytes are still unclear. Given that oxidative stress mediates podocyte injury under a variety of pathological situations, we examined the possible involvement of an oxidative stress-related mechanism in the regulation of Cx43. Incubation of podocytes with puromycin led to a time- and concentration-dependent loss of cell viability, which was preceded by an elevation in Cx43 levels. Concomitantly, puromycin also induced NOX4 expression and promoted superoxide (O(2)(·-)) generation. Inhibition of NADPH oxidase with apocynin and diphenyleneiodonium chloride or addition of the superoxide dismutase mimetic tempol completely abrogated, whereas the O(2)(·-) donors menadione and 2,3-dimethoxy-1,4-naphthoquinone reproduced, the effects of puromycin on Cx43 expression and cell injury. Further analysis demonstrated that treatment of podocytes with several structurally different gap-junction inhibitors significantly attenuated the cytotoxicity of puromycin. Our results thus indicate that NADPH oxidase-mediated upregulation of Cx43 contributes to podocyte injury.

[Regulatory mechanism of p38MAPK signaling pathway on renal tissue inflammation in chronic kidney disease and interventional effect of traditional Chinese medicine]

The inflammatory reaction of renal tissues and its relevant tissue damages (such as glomerulosclerosis and renal interstitial fibrosis) are important factors for the development of chronic kidney diseases (CKD) to end-state renal diseases. Of them, p38 mitogen-activated protein kinase (MAPK) signaling pathway plays an important role in regulating expression and bioactivity of multiple nuclear transcription factors, impacting synthesis of downstream inflammatory mediators and activating inflammatory cells. Some monomer traditional Chinese medicines and their extracts (such as emodin and berberine) and some traditional Chinese medicine compound prescriptions (such as Yishen Huoxue decoction) can affect inflammatory reaction of renal tissues by regulating p38MAPK signaling pathway, thas improving reduce glomerulus and renal interstitial inflammatory injury.

[Mechanisms and effects of chinese herbal medicine delaying progression of chronic renal failure]

In this review,firstly,it has been discussed the mechanisms of Chinese herbal medicine ameliorating glomerulosclerosis and renal interstitial fibrosis during the progression of chronic renal failure (CRF) by improving glomerular hemodynamics turbulence, podocyte injury, transforming growth factor (TGF)-beta over-expression, hyperlipidemia, macrophage infiltration, tubular epithelial myofibroblast transdifferentiation, and nephrotoxicity of proteinuria. Secondly,it has been reported the clinical effects of Chinese herbal medicine improving renal function and some clinical complications in the patients with progressive CRF through various treatments including oral administration or coloclysis of Chinese herbal medicine, oral administration combined with coloclysis of Chinese herbal medicine, and colonic dialysis combined with coloclysis of Chinese herbal medicine. Finally,it has been reviewed the beneficial influences of Chinese herbal medicine on metabolic dysequilibrium of calcium and phosphonium, microinflammatory state, and uremic toxins in patients with uremia.

[Effect of multi-glycoside of Tripterygium wilfordii Hook. f. in intervening TGF-beta1/Smad signaling pathway of adriamycin-induced nephropathy model rat]

OBJECTIVE

To explore the potential molecular mechanisms of multi-glycoside of Tripterygium wilfordii Hook. f. (GTW) for ameliorating glomerulosclerosis (GS) by observing its intervention effect on transforming growth factor (TGF)-beta1/Smad signaling pathway in adriamycin-induced nephropathy (ADRN) model rat.

METHODS

Fifteen female Sprague-Dawley (SD) rats were randomly divided into three groups, the sham-operation group (A), the untreated model group (B), and the GTW treated model group (C). Rats in Group B and C were made into ADRN model by right nephrectomy and intravenous injection of adriamycin (ADR, 0. 4 mL and 0. 2 mL respectively in 4 weeks). After the model was successfully established, rats in Group C were orally given GTW (50 mg/kg per day), while rats in Group B were intervened with distilled water. The intervention for two groups was 6 weeks. Rats' body weight were weighed and 24 h urinary protein excretion (Upro) detected by the end of the 2nd, 4th, 8th and 10th week. All rats were sacrificed at the end of 10th week after operation to withdraw blood and kidney tissue to examine serum biochemical parameters, glomerular morphological changes, alpha-smooth muscle actin (alpha-SMA), and collagen type I expression. Besides, the mRNA expressions of TGF-beta1, Smad3 and Smad7, as well as protein expressions of TGF-beta1, and phosphorylated Smad2/3 (p-Smad2/3) in glomeruli were detected by RT-PCR or Western blotting.

RESULTS

As compared with Group B, in Group C, Upro and serum albumin were improved significantly, but no difference between groups was found in levels of blood urea nitrogen(BUN), serum creatinine(SCr), or hepatic cell injury. Mesangial cell proliferation, extracellular matrix (ECM) and collagen deposition were suppressed by GTW. Expressions of alpha-SMA and collagen type I decreased, and the characteristic changes of GS were attenuated. The mRNA expressions of TGF-P,31, Smad3 and protein expression of TGF-beta1, p-Smad2/3 in renal tissues were down-regulated, while the protein expression of Smad7 mRNA was up-regulated.

CONCLUSION

GTW showed effect in ameliorating GS in vivo. It could reduce the ECM deposition and improve GS by way of intervening TGF-beta1/Smad signaling pathway in the kidney through regulating the mRNA or protein expressions of key signal molecules, such as Smad3 and p-Smad2/3.

[Regulative mechanism of Chinese herbal medicine on cell signaling pathway in kidney]

In kidney, the role of cell proliferation, differentiation, apoptosis, inflammatory mediators and cytokines expression is closely related with cell signaling pathways, including tyrosine kinase pathway, transforming growth factor-beta/Smad pathway, Rho/Rho-associated coiled-coil forming protein kinase pathway, phosphoinositol pathway, cyclic nucleotide pathway, nuclear factor kappaB pathway and so on. Some Chinese herbs and their extracts, such as rhubarb and triptolide, as well as some Chinese herbal prescriptions, such as astragalus-angelica mixture and Chailing decoction, not only could ameliorate proliferation, differentiation and apoptosis of renal cell by regulating cell signaling pathways, but also could control target gene transcription, expression and its biological effects through inhibiting the phosphorylation of key signaling molecules.

Disruption of gap junctions attenuates aminoglycoside-elicited renal tubular cell injury

BACKGROUND AND PURPOSE

Gap junctions play important roles in the regulation of cell phenotype and in determining cell survival after various insults. Here, we investigated the role of gap junctions in aminoglycoside-induced injury to renal tubular cells.

EXPERIMENTAL APPROACH

Two tubular epithelial cell lines NRK-E52 and LLC-PK1 were compared for gap junction protein expression and function by immunofluorescent staining, Western blot and dye transfer assay. Cell viability after exposure to aminoglycosides was evaluated by WST assay. Gap junctions were modulated by transfection of the gap junction protein, connexin 43 (Cx43), use of Cx43 siRNA and gap junction inhibitors.

KEY RESULTS

NRK-E52 cells expressed abundant Cx43 and were functionally coupled by gap junctional intercellular communication (GJIC). Exposure of NRK-E52 cells to aminoglycosides, G418 and hygromycin, increased Cx43 phosphorylation and GJIC. The aminoglycosides also decreased cell viability that was prevented by gap junction inhibitors and Cx43 siRNA. LLC-PK1 cells were gap junction-deficient and resistant to aminoglycoside-induced cytotoxicity. Over-expression of a wild-type Cx43 converted LLC-PK1 cells to a drug-sensitive phenotype. The gap junction inhibitor alpha-glycyrrhetinic acid (alpha-GA) activated Akt in NRK-E52 cells. Inhibition of the Akt pathway enhanced cell toxicity to G418 and abolished the protective effects of alpha-GA. In addition, gentamycin-elicited cytotoxicity in NRK-E52 cells was also significantly attenuated by alpha-GA.

CONCLUSION AND IMPLICATIONS

Gap junctions contributed to the cytotoxic effects of aminoglycosides. Modulation of gap junctions could be a promising approach for prevention and treatment of aminoglycoside-induced renal tubular cell injury.

[Preventive effects of multi-glycoside of Tripterygium wilfordii on glomerular lesions in experimental diabetic nephropathy]

OBJECTIVE

To observe the preventive effects of multi-glycoside of Tripterygium wilfordii (GTW) on glomerular lesions in experimental diabetic nephropathy (DN).

METHOD

The DN model of rats was established with streptozotocin (STZ) and intervened with GTW. In the same time, normal, benazepril, and vehicle control groups were set up. After 8 weeks of oral treatment with GTW (50 mg x kg(-1) BW), benazepril (6 mg x kg(-1) BW), and vehicle (physiological saline), the changes of body weight, urine albumin (UA1b), blood glucose (BG), serum creatinine (Scr), blood urea nitrogen (BUN) and glomerular morphology were examined. In addition, the level of protein expression of alpha-smooth muscle actin (alpha-SMA) and collagen type I in glomeruli was determined by immunofluorescence.

RESULT

Both GTW and benazepril reduced UA1b. GTW ameliorated glomerular injury, such as mesangial cell proliferation, alpha-SMA and collagen type I over-expression, in DN model. Compared with benazepril, beneficial effects of GTW on glomerulusclerosis were more significant (total cell number: GTW group 54.44 +/- 2.41, benazepril group microg/67.83 +/- 4.41, P < 0.05; alpha-SMA score: GTW group 1.98 +/- 0.52, benazepril group 2.27 +/- 0.46, P < 0.05; collagen type I score: GTW group 2.11 +/- 0.37, benazepril group 2.88 +/- 0.58, P < 0.05).

CONCLUSION

Preventive effects of GTW on glomerular lesion in DN model are related to decreasing UA1b and ameliorating glomerulusclerosis.

Downregulation of gap junction expression and function by endoplasmic reticulum stress

Gap junctional intercellular communication (GJIC) plays a critical role in the control of multiple cell behavior as well as in the maintenance of tissue and organ homeostasis. However, mechanisms involved in the regulation of gap junctions (GJs) have not been fully understood. Given endoplasmic reticulum (ER) stress and dysfunction of GJs coexist in several pathological situations, we asked whether GJs could be regulated by ER stress. Incubation of mesangial cells with ER stress-inducing agents (thapsigargin, tunicamycin, and AB(5) subtilase cytotoxin) resulted in a decrease in connexin 43 (Cx43) expression at both protein and mRNA levels. This was accompanied by a loss of GJIC, as evidenced by the reduced numbers of dye-coupled cells after single cell microinjection or scrape loading dye transfer. Further studies demonstrated that ER stress significantly inhibited the promoter activity of the Cx43 gene, reduced [(35)S]-methionine incorporation into Cx43 protein and accelerated degradation of Cx43. ER stress also decreased the Cx43 protein levels in several different cell types, including human umbilical vein endothelial cells, mouse-derived renin-secreting cells and human hepatoma cells. Furthermore, induction of ER stress by hypoxic chemicals thenoyltrifluoroacetone and cobalt chloride was found to be associated with a reduction in Cx43. Our findings thus reveal a close link between ER stress and GJs. ER stress may represent a novel mechanism underlying the altered GJs in a variety of pathological situations.

[Mechanism of Chinese herbal medicine delaying progression of chronic kidney disease]

The pathomechanisms of the progression of chronic kidney disease (CKD) include glomerulosclerosis, renal interstitial fibrosis and renal arteriosclerosis. Chinese herbal medicine can delay the progression of CKD by ameliorating the harmful factors of these pathological changes, such as podocyte and slit diaphragm injury, nephrotoxicity of proteinuria, hyperactivity of renin-angiotensin-aldosterone system, cytokines over-expression, tubular epithelial myofibroblast transdifferentiation, hyperlipidemia and hypertension.

[Suppressive effects of GTW treatment on infiltration of inflammatory cell in glomeruli in anti-Thy1.1 glomerulonephritis]

OBJECTIVE

To examine inhibition action of multi-glycoside of Tripterygium wilfordii (GTW) on infiltration of inflammatory cell in glomeruli with anti-Thy1.1 glomerulonephritis (anti-Thy1.1 GN), and to clarify its effects on inflammatory in vitro.

METHOD

Two types of anti-Thy1.1 GN were induced in rats by a single or two intravenous injections with 500 microg of anti-Thy1.1 mAb 1-22-3. Rats were randomly divided into two groups, the GTW group and control group, and sacrificed on day 7 or on day 42 after induction of anti-Thy1.1 GN. Daily oral administration of different dose of GTW and distilled water as a control was started from 3 days before injection or at the same time of injection till the day of sacrifice. Proteinuria was determined during days 7 or during days 42. Infiltration of macrophage and T lymphocyte in glomeruli and mRNA expression of interleukin (IL)-2 and interferon (IFN)-gamma in renal tissue were examined.

RESULT

Increase of infiltration of macrophage in reversible anti-Thy1.1 GN model, glomerular macrophage infiltration and IL-2 mRNA expansion were attenuated by higher dose of GTW (75 mg x kg(-1) x d(-1)), and increased accumulation of activated macrophage and T lymphocyte in irreversible anti-Thy1.1 GN model, accumulation of macrophage and T lymphocyte in glomeruli and mRNA expansion of IL-2 and IFN-gamma were decreased by middling dose of GTW (50 mg x kg(-1) x d(-1)) as well. Proteinuria was significantly ameliorated after GTW administration.

CONCLUSION

The findings suggested that different dose of GTW can ameliorate infiltration of inflammatory cell in glomeruli with anti-Thy1.1 glomerulonephritis in vitro by decreasing the expression of IL-2 and IFN-gamma.

[Study on correlation between TCM syndrome and urinary protein in patients with early chronic kidney diseases]

OBJECTIVE

To analyze the characteristics of TCM syndrome distribution and its correlation with urinary protein in patients with early chronic kidney diseases (CKD), for the sake of providing a basis for clarifying the rules of TCM syndrome differentiation in CKD.

METHODS

Adopting traditional epidemiological retrospective method, the TCM syndrome and urinary protein related indexes, including 24 h urinary protein (Upro), urinary albumin (UAlb), urinary beta2-microglobulin (Ubeta2-MG), urinary N-acetyl-beta-D-glucosaminidase (UNAG), urinary beta-galactosidase (UGAL), etc, were collected from 199 patients with early CKD, and a multiple factor regression analysis between them was conducted.

RESULTS

In patients with early stage CKD, the TCM symptoms, as independent factors closely related to urinary protein, were aching loins, poor appetite and indigestion, yellow and brownish urine, regurgitation acid, profuse nocturnal urine, edema, foamy urine, cough, aversion to cold and cold limbs, etc; the elevation of UAlb with the factors of Pi-Shen qi-deficiency as aching loins, poor appetite and indigestion was correlated; elevation of UNAG with edema, foamy urine, profuse nocturnal urine, cough; UGAL with Pi-Shen yang-deficiency factors as aching loins, aversion to cold and cold limbs; and elevation of Ubeta2-MG with edema were correlated respectively as well. Levels of UAlb and UNAG in patients of Pi-Shen qi-deficiency type were significantly higher than those in patients of Gan-Shen yin-deficiency type, Fei-Shen qi-deficiency type, and Pi-Shen yang-deficiency type, respectively (all P < 0.05).

CONCLUSION

For early stage CKD patients, Shen and Pi are the major organs related to the appearance of urinary protein; Pi-Shen deficiency is the basic pathogenesis. Level of UAlb, which is associated with Pi-Shen qi-deficiency type, could be taken as one of microcosmic syndrome factors for the syndrome type; UNAG also be related with that syndrome to certain extent; and heat-damp syndrome might be an independent type.

[Preventive effect of multi-glycoside of tripterygium Wilfordii Hook. f. on proteinuria and mesangial injury in experimental mesangial proliferative glomerulonephritis]

OBJECTIVE

To observe the preventive effect of multi-glycoside of Tripterygium Wilfordii Hook. f. (GYW) on proteinuria and mesentery injury in experimental mesangial proliferative glomerulonephritis in vivo.

METHODS

The reversible anti-Thyl.1 antibody glomerulo nephritis model of rats was established with monoclonal antibody 1-22-3 and intervened with GTW, and a control group was set up in the same time. Changes of 24h urinary protein excretion, serum creatinine (Scr), blood urea nitrogen (BUN), total plasma protein (TP) and glomerular morphology were observed, and the level of mRNA expression of proliferative factors, including platelet-derived growth factor-BB (PDGF-BB) and transforming growth factor-beta (TGF-beta), in renal tissue was determined.

RESULTS

GTW could inhibit proteinuria and mesangial injury in anti-Thyl. 1 antibody nephritis model. The PDGF-BB and TGF-beta mRNA expression in the anti-Thy1.1 antibody nephritis model rats were increased for 2.84 and 1.64 times respectively to those in the normal control group. GTW could down-regulate the over-expression of PDGF-BB mRNA by 33.1%, it was significantly different to that in the control group (P < 0.05).

CONCLUSION

GTW could reduce the proteinuria and inhibit mesangial cells proliferation and extracellular matrix deposition, these effects maybe related to the down-regulating of PDGF-BB mRNA expression.

[Suppressive effects of GTW treatment on mesangial lesions in experimental irreversible glomerulosclerosis]

OBJECTIVE

To examine suppressive effects of multi-glycoside of Tripterygium wilfordii Hook. f. (GTW)on mesangial injury induced by two-injecti on of anti-Thy1. 1 monoclonal antibody(mAb) 1-22-3 in vitro.

METHOD

We established the irreversible model of glomerulosclerosis with anti-Thy1. 1 mAb 1-22-3. After 42 days of oral treatment with GTW (50 mg x kg(-1) BW)and vehicle (distilled water), to observe effects of GTW on proteinuria, renal function, mesangial morphological change, and mRNA expressions of collagen type I and TGF-beta by light microscope (LM), immunofluorescence (IF), and Reverse Transcription Polymerase Chain Reaction (RT-PCR).

RESULT

GTW ameliorated proteinuria (from day24 to day 42) and mesangial proliferation [total cell number, GTW group 65.67+/-3.43 vs. control group 87.02+/-2.41, P < 0.05; matrix expansion, GTW group 1.20+/-0.06 vs. control group 2.77+/-0.23, P < 0.05; alpha-smooth muscle actin(alpha-SMA) expression, GTW group 1.75+/-0.33 vs. control group 2.62+/-0.15, P < 0.05; collagen type I expression, GTW group 1.68+/-0.31 vs. control group 2.06+/-0.24, P < 0.05], moreover, significantly reduced the glomerular expression of mRNA for collagen type 1(53.5% to the control group, P < 0.05)and TGF-beta(14.7% to the control group, P < 0.05)on day 42day.

CONCLUSION

GTW can not only decrease proteinuria, but also ameliorate mesangial alterations probably by the reduction of cytokines. GTW may be a promising agent for the prevention of progressive and irreversible glomerulosclerosis.

Multi-glycoside of Tripterygium wilfordii Hook f. ameliorates proteinuria and acute mesangial injury induced by anti-Thy1.1 monoclonal antibody

BACKGROUND/AIMS

Multi-glycoside from Tripterygium wilfordii Hook f. (GTW) is used for various immune and inflammatory diseases including renal diseases represented by mesangial proliferative glomerulonephritis (MsPGN) in China. However, there have been no fundamental studies on the operating mechanism of GTW on MsPGN. The aim of this study is to examine as the first step the effects of GTW on acute injurious process such as mesangial injury and proteinuria in an acute and reversible Thy.1.1 glomerulonephritis (Thy1.1GN) model and then to clarify the action mechanism of GTW at molecular level by examining its effects on various injurious factors in this model.

METHODS

Thy1.1 GN was induced in rats by a single intravenous injection with 500 microg of anti-Thy1.1 mAb 1-22-3. Daily oral administration of GTW and vehicle as a control was started from 3 days before injection of mAb to the day of sacrifice in each experiment. Fourteen rats were randomly divided into 2 groups, GTW-treated and vehicle-treated groups, and sacrificed on day 14 in experiment 1 or on day 7 in experiment 2 after induction of Thy1.1 GN. Proteinuria was determined on days 1, 3, 5, 7, 10 and 14 in experiment 1 or on 1, 3, 5 and 7 in experiment 2. From blood and kidneys taken at sacrifice, blood biochemical parameters, mesangial morphological changes, glomerular macrophage infiltration, and glomerular mRNA expression of cytokines were examined.

RESULTS

In experiment 1, proteinuria and mesangial matrix expansion were significantly attenuated by GTW treatment. In experiment 2, GTW treatment significantly ameliorated proteinuria, mesangial lesions and macrophage accumulation in glomerulus. In addition, it significantly reduced the glomerular expression of mRNA for PDGF, MCP-1 and IL-2.

CONCLUSION

GTW ameliorated not only proteinuria but also mesangial alterations in Thy1.1 GN most likely by reducing expression of injurious cytokines, indicating that GTW has suppressive effects on acute inflammatory changes in glomeruli.

[Effect of the compound of traditional Chinese drugs on gene expression of renal endothelin and its receptor of experimental diabetic nephropathy]

OBJECTIVE

To study the effect of the Compound of traditional Chinese drugs and Benazepril on gene expression of renal endothelin and its receptor of experimental diabetic nephropathy(DN). To discove the mechanism of the compound of traditional Chinese drugs in treating DN.

METHOD

Streptozotocin DN model was built and influenced with the compound of traditional Chinese drugs and Benazepril. The changes of Upro, Glu, HbA1C and (PT-PCR) mRNA expression levels of ET-1, ETA-R of the renal cortex were tested, and thus the histopathological character of the kidney was analysed.

RESULT

The compound of traditional Chinese drugs and Benazepril have significant difference from normal saline in the improvement of Upro, Glu, HbA1C. The compound of traditional Chinese drugs have significant difference from Benazepril in the improvement of Glu, HbA1C. The mRNA expression level of ET-1, ETA-R of the renal cortex of DN model was raised. After influenced by the compound of traditional Chinese drugs and Benazepril, the over-expression level de-creased (still higher than normal control ones). The compound of traditional Chinese drugs were more effective than Benazepril to inhibit the proliferation of the stalk region and the third cells.

CONCLUSION

ET takes part in the process of diabetic glo-Merulosclerosis. Both the compound of traditional Chinese drugs and Benazepril can influence the expression quantity from the level of gene transcription of ET and its receptor. The compound of traditional Chinese drugs can not only reduce urinary albumin of DN, but also improve blood glucose, glycosylated hemoglubin. And it can inhibit nonenzymatic glucosylation of protein as well as the proliferation of the stalk region and the third cells.

[Effects of the zhikuofang on the inflammation and cytostatics of the airway model of bronchiectasis]

OBJECTIVE

To explore the effects of Zhikuofang, a TCM prescription, and Ofloxacin on the inflammation and cytostatics of the airway model of bronchiectasis.

METHOD

The airway model of bronchiectasis (AMB) was set up and infused with Ps. Aeruginosa. A comparison between the effects of Zhikuofang and Of loxacin on the AMB was made.

RESULT

Zhikuofang is better than Ofloxacin in following aspects: lowering the density of inflammation cells in blood, decreasing the volume of tracheal secretion and inhibiting the cytostatics (IL-8 and TNF-alpha) of the trachea tissue, but Ofloxacin is more effective in diminishing the amount of bacteria in trachea flushing liquor. There was no marked difference between them in their histopathy effects on the trachea.

CONCLUSION

Zhikuofang probably plays antiphlogistic and bacteriostatic effects by inhibiting the IL-8 and TNF-alpha, resisting secretion, decreasing the inflammation cells and resisting inflammation of trachea.