Junming Fan

Peripheral B lymphocyte β1,3‐galactosyltransferase and chaperone expression in immunoglobulin A nephropathy

Purpose.  Aberrant O‐glycosylation of serum IgA1 is presumed to be one of the main pathogenesis of immunoglobulin A nephropathy (IgAN). β1,3‐galactosyltransferase (β1,3GT), whose activity requires coexistence of a specific chaperone, is the main enzyme which participate in the glycosylation process. The current study was carried out to elucidate the expression level of β1,3GT (C1GALT1) and its chaperone (Cosmc) in IgAN, and their relationships with clinical features as well as IgA glycosylation level.

C-reactive protein promotes acute renal inflammation and fibrosis in unilateral ureteral obstructive nephropathy in mice

Elevated blood level of C-reactive protein (CRP) is associated with increased risk of chronic kidney disease. However, whether this association reflects functional importance of CRP in the pathogenesis of kidney disease remains unclear. In this study, we examined the biological role of CRP in a well-characterized model of progressive kidney disease, unilateral ureteral obstruction (UUO), in mice that express the human CRP gene (CRPtg). Compared with wild-type (Wt) mice at 3 days after UUO, CRPtg mice developed more severe renal inflammation with a significant increase in tubulointerstitial T cells and macrophages, upregulation of proinflammatory cytokines (IL-1β and TNF-α), chemokines (MCP-1), and adhesion molecules (ICAM-1). Renal fibrosis was also significantly enhanced in CRPtg mice as demonstrated by increased expression of tubulointerstitial α-smooth muscle actin and collagen types I and III compared with Wt mice. Interestingly, on days 7 and 14 after UUO, an equal severity of renal inflammation and fibrosis were observed in CRPtg and Wt mice. These findings suggested that CRP may have a role in the initiation of renal inflammation and fibrosis. Further study revealed that enhanced early renal inflammation and fibrosis on day 3 in CRPtg mice was associated with a significant upregulation of endogenous mouse CRP and FcγRI mRNA and increased activation of both NF-κB/p65 and TGF-β/Smad2/3 signaling, while equal severity of progressive renal injury at day 7 and day 14 between CRPtg and Wt mice were attributed to equivalent levels of CRP, FcγRI, phospho-NF-κB/p65, and TGF-β/Smad2/3 signaling. Based on these findings, we conclude that CRP may not only be a biomarker, but also a mediator in the early development of renal inflammation and fibrosis in a mouse model of UUO. Enhanced activation of both NF-κB and TGF-β/Smad signaling pathways may be mechanisms by which CRP promotes early renal inflammation and fibrosis.

Efficacy and safety of lanthanum carbonate on chronic kidney disease–mineral and bone disorder in dialysis patients: a systematic review

BackgroundChronic kidney disease–mineral and bone disorder (CKD–MBD) is a common complication in CKD patients, particularly in those with end-stage renal disease that requires dialysis. Lanthanum carbonate (LC) is a potent, non-aluminum, non-calcium phosphate binder. This systematic review evaluates the efficacy and safety of LC in CKD-MBD treatment for maintenance-dialysis patients.MethodsA systematic review and meta-analysis on randomized controlled trials (RCTs) and quasi-RCTs was performed to assess the efficacy and safety of LC in maintenance hemodialysis or peritoneal dialysis patients. Analysis was performed using the statistical software Review Manager 5.1.ResultsSixteen RCTs involving 3789 patients were identified and retained for this review. No statistical difference was found in all-cause mortality. The limited number of trials was insufficient to show the superiority of LC over other treatments in lowering vascular calcification or cardiovascular events and in improving bone morphology, bone metabolism, or bone turn-over parameters. LC decreased the serum phosphorus level and calcium × phosphate product (Ca × P) as compared to placebo. LC, calcium carbonate (CC), and sevelamer hydrochloride (SH) were comparable in terms of controlling the serum phosphorus, Ca × P product, and intact parathyroid hormone (iPTH) levels. However, LC resulted in a lower serum calcium level and a higher bone-specific alkaline phosphatase level compared with CC. LC had higher total cholesterol and low-density lipoprotein (LDL) cholesterol levels compared with SH. LC-treated patients appeared to have a higher rate of vomiting and lower risk of hypercalcemia, diarrhea, intradialytic hypotension, cramps or myalgia, and abdominal pain. Meta-analysis showed no significant difference in the incidence of other side effects. Accumulation of LC in blood and bone was below toxic levels.ConclusionsLC has high efficacy in lowering serum phosphorus and iPTH levels without increasing the serum calcium. Current evidence does not show a higher rate of adverse effects for LC compared with other treatments, except for a higher incidence of vomiting. Moreover, LC accumulation in blood and bone was below toxic levels. Well-designed studies should be conducted to evaluate the long-term effects of LC.

Ginsenoside Rg1, a major active component isolated from Panax notoginseng, restrains tubular epithelial to myofibroblast transition in vitro

The medicinal herb, Panax notoginseng, has been used for thousands of years in traditional Chinese medicine and possesses anti-fibrosis properties. Epithelial-myofibroblast transition (EMT) plays an important role in renal tubulointerstitial fibrosis. The present study was designed to examine whether ginsenoside Rg1, a major active component isolated from Panax notoginseng, has an ability to block this phenotypic transition in rat renal tubular epithelial cells (NRK-52E) induced by transforming growth factor-beta1 (TGF-beta1). The morphology of tubular epithelial-myofibroblast transition was observed through light microscope and transmission electron microscopy. alpha-SMA and E-cadherin are two markers of tubular epithelial-myofibroblast transition, their protein expressions were assessed by immunohistochemistry and western blot analysis. Gene expression of alpha-SMA as well as the two major extracellular matrix components collagen I and fibronectin was measured by real-time PCR analysis. Enzyme-linked immunosorbent assay was used to quantitatively detect collagen I and fibronectin in the supernatant. Our results revealed that ginsenoside Rg1 obviously blocked morphologic transformation in NRK-52E induced by TGF-beta1. Meanwhile, ginsenoside Rg1 inhibited the expression of alpha-SMA and the loss of E-cadherin, subsequently decreased the levels of collagen I and fibronectin in a dose-dependent manner. In addition, western blot analysis indicated that ginsenoside Rg1 inhibited the expression of P-ERK1/2 in NRK-52E induced by TGF-beta1. These results suggest that ginsenoside Rg1 can restrain the process of EMT maybe via suppressing the expression of P-ERK1/2 in vitro.

Astragaloside IV attenuates complement membranous attack complex induced podocyte injury through the MAPK pathway.

Membranous nephropathy (MN) is the most common cause of idiopathic nephrotic syndrome in adults and the cause is known to be due to the injury of podocytes located in the glomeruli. Astragalus membranaceus has been used for the treatment of patients with MN in China for a long time. The beneficial effect of Astragalus membranaceus on proteinuria of patients with MN has been well documented. However, the mechanism of astragalus membranaceu in alleviation of MN is still not completely understood. Therefore, in the current study, we employed a podocyte injury model induced by complement membranous attack complex to examine the mechanism of astragalus membraneceus in the treatment of MN. We found that complement membranous attack complex could increase lactate dehydrogenase (LDH) release from podocytes and astragaloside IV (AS‐IV) could prevent LDH release from podocytes in a time‐ and dose‐dependent pattern. Moreover, AS‐IV restored podocyte morphology and cytoskeleton loss induced by complement membranous attack complex. Furthermore, AS‐IV was able to reduce phosphorylation of JNK and ERK1/2 induced by complement membranous attack complex. In conclusion, the mechanism of Astragalus membranaceus in the treatment of MN may be related to its attenuation of podocyte injury through regulation of cytoskeleton and mitogen activated protein kinase. Copyright

Ginsenoside Rb1,a Panoxadiol Saponin against Oxidative Damage and Renal Interstitial Fibrosis in Rats with Unilateral Ureteral Obstruction

ObjectiveTo investigate the possible protective effect and mechanism of ginsenoside Rb1 against oxidative damage and renal interstitial fibrosis on rats with unilateral ureteral obstruction (UUO).MethodsIn total, 80 male rats were randomly divided into 4 groups, 20 in each group: the sham operated group (SOR), UUO group, UUO with ginsenoside Rb1 treatment group (treated with intraperitoneal injection of 50 mg/ kg daily) and UUO with Losartan treatment group (as the positive control, treated with 20 mg/kg by gastrogavage per day). The rats were randomly sacrifificed on day 3, 7 and 14 after surgery, respectively. The histopathologic changes of renal interstitial tissues were observed with Masson staining. The mRNA of transforming growth factor β 1 (TGF-β 1), collagen I and fibronectin were reversed transcribed and quantified by Real-time PCR. Enzyme-linked immunosorbent assay was used to quantitatively detect TGF-β 1 and 8-hydroxy-2′-deoxyguanosine (8-OHdG) levels. P47phox protein expression was assessed by immunohistochemistry and Western blot analysis.ResultsIn the UUO model, the obstructed kidney showed typical features of progressive renal tubulointerstitial fibrosis, and the levels of TGF-β1, collagen I and fibronectin increased (P<0.05). As compared with the UUO group, ginsennoside Rb1 significantly inhibited the interstitial fibrosis including tubular injury and collagen deposition, and decreased the levels of TGF-β1 (P<0.05). Ginsenoside Rb1 also inhibited the heme oxygenase (HO-1) and 8-OHdG, two markers of oxidative stress (P<0.05). Moreover, ginsenoside Rb1 suppressed the expression of p47phox, a subunit of nicotinamide adeninedinucleotide phosphate (NADPH) oxidase (P<0.05).ConclusionGinsenoside Rb1 can obviously inhibit renal interstitial fibrosis in rats with UUO, its mechanism possibly via against the oxidative damage and suppressing TGF-β1 expression.

LSKL, a peptide antagonist of thrombospondin-1, attenuates renal interstitial fibrosis in rats with unilateral ureteral obstruction

The effects of LSKL, the peptide antagonist of thrombospondin-1 (TSP-1), on renal interstitial fibrosis in rats subjected to unilateral ureteral obstruction (UUO) were investigated. Rats were divided randomly into three groups (n = 20 each): UUO group, sham-operation group and UUO plus LSKL treatment group. Collagen deposition was studied using histopathology and reverse transcription polymerase chain reaction analysis (RT-PCR). TSP-1, transforming growth factor beta 1 (TGF-β1), phosphorylated Smad2 (pSsmad2) and α-smooth muscle actin (α-SMA) in the kidney were measured using immunocytochemistry, western blotting analysis, RT-PCR and enzyme-linked immunosorbent assay. Biochemical analyses in the serum and urine were made. Histopathology showed severe tubular dilatation and atrophy, interstitial inflammation and collagen accumulation after surgery and LSKL significantly inhibited interstitial fibrosis including tubular injury as well as collagen deposition. The protein and mRNA levels of TSP-1 increased notably at different time point and significantly decreased in the presence of LSKL. The expression of TGF-β1 and pSmad2 were upregulated in the obstructed kidney and substantially suppressed by LSKL treatment. Myofibroblast accumulation could be alleviated after administration of LSKL. Biochemical parameters did not show differences among the three groups. As TSP-1 is the major activator of TGF-β1, we demonstrate that LSKL can attenuate renal interstitial fibrosis in vivo by preventing TSP-1-mediated TGF-β1 activation.

Astragalus mongholicus ameliorates renal fibrosis by modulating HGF and TGF-β in rats with unilateral ureteral obstruction

Astragalus mongholicus (AM) derived from the dry root of Astragalus membranaceus Bge. var. mongolicus (Bge.) Hsiao is a widely used traditional Chinese medicine. The present study investigated the potential role of AM on renal fibrosis on a rat model of unilateral ureteral obstruction (UUO). We divided 48 Sprague-Dawley rats randomly into 4 groups: sham-operated group (Sham), untreated UUO group, AM-treated (10 g/(kg·d)) UUO group, and losartan-treated (20 mg/(kg·d)) UUO group as positive control. Haematoxylin & eosin (HE) and Masson staining were used to study the dynamic histological changes of the kidneys 7 and 14 d after operation. The expressions of fibronectin (FN), type I collagen (colI), hepatocyte growth factor (HGF), transforming growth factor-β1 (TGF-β1), and α-smooth muscle actin (α-SMA) were analyzed by real-time polymerase chain reaction (PCR), immunohistochemistry staining, and Western blot. Results show that, similar to losartan, AM alleviated the renal damage and decreased the deposition of FN and colI from UUO by reducing the expressions of TGF-β1 and α-SMA (P<0.05), whereas HGF increased greatly with AM treatment (P<0.05). Our findings reveal that AM could retard the progression of renal fibrosis. The renoprotective effect of AM might be related to inhibition of myofibroblast activation, inducing of HGF and reducing of TGF-β1 expression.

Ginsenoside Rg1 Modulation on Thrombospondin-1 and Vascular Endothelial Growth Factor Expression in Early Renal Fibrogenesis in Unilateral Obstruction

Renal interstitial fibrosis is the major histopathological change seen in a variety of renal disorders and is closely related to renal dysfunction. Progressive interstitial fibrosis accompanied by the loss of renal tubules and interstitial capillaries typifies all progressive renal disease. Thrombospondin‐1 (TSP‐1) is a major angiogenic inhibitor. It is demonstrated that TSP‐1 levels were correlated with the loss of glomerular and peritubular capillaries and TSP‐1 could promote renal scarring by effects on the endothelium. It has been reported that ginsenoside Rg1 inhibited renal interstitial fibrosis in rats via suppressing the expression of TSP‐1. The present study was designed to examine whether ginsenoside Rg1 could modulate the integrity of the microvasculature and hence affect the progression of renal fibrosis in a rat unilateral ureteral obstruction (UUO) model. In UUO control kidneys, associated with interstitial fibrosis, lower peritubular capillary densities were prominent. These changes were all improved by ginsenoside Rg1 treatment. Interestingly, ginsenoside Rg1 decreased the expression of TSP‐1 and enhanced vascular endothelial growth factor (VEGF) expression. The results show for the first time that ginsenoside Rg1 can evidently inhibit renal interstitial fibrosis in rats with UUO. The mechanism might be related to suppression of the expression of TSP‐1 and to repair of the peritubular capillary. Copyright

Ginsenoside Rg1 protects mouse podocytes from aldosterone-induced injury in vitro

Aim:Aldosterone is elevated in many diseases such as hypertension, diabetic nephropathy and chronic kidney disease, etc. The aim of this study was to investigate the effects of aldosterone on intracellular ROS production and autophagy in podocytes in vitro, and to explore the possibility of ginsenoside Rg1 (Rg1) being used for protecting podocytes from aldosterone-induced injury.Methods:MPC5 mouse podocyte cells were tested. Autophagosome and autophagic vacuole formation were examined under confocal microscopy with MDC and acridine orange staining, respectively. ROS were detected with flow cytometry. Malondialdehyde content and superoxide dismutase (T-SOD) activity were measured using commercial kits. The expression of LC3-II, beclin-1, SOD2 and catalase was measured by Western blotting.Results:Treatment with aldosterone (10 nmol/L) significantly increased ROS generation and the expression of SOD2 and catalase in MPC5 cells. Furthermore, treatment with aldosterone significantly increased the conversion of LC3-I to LC3-II, beclin-1 expression and autophagosome formation. Co-treatment with rapamycin (1 ng/mL) or chloroquine (10 μmol/L) further increased aldosterone-induced autophagosome formation. Co-treatment with Rg1 (80 ng/mL) effectively relieved oxidative stress and increased T-SOD activity at the early stage and subsequently decreased autophagy in aldosterone-treated podocytes. Co-treatment with 3-MA (4 mmol/L) or NAC (50 mmol/L) exerted similar effects against aldosterone-induced autophagy in podocytes.Conclusion:Aldosterone enhances ROS generation and promotes autophagy in podocytes in vitro. Ginsenoside-Rg1 effectively relieves aldosterone-induced oxidative stress, thereby indirectly inhibiting aldosterone-induced podocyte autophagy.