Transplantation of Telocytes Attenuates Unilateral Ureter Obstruction-Induced Renal Fibrosis in Rats.

BACKGROUND/AIMS: Previous studies imply that telocytes may have a protective effect on fibrosis in various organs, including the liver, colon, and heart. The effect of telocytes on renal fibrosis remains unknown. Herein, this study was designed to investigate the effect of telocytes on renal fibrosis and the potential mechanisms involved. METHODS: In a unilateral ureteral obstruction (UUO)-induced renal fibrosis model, telocytes were injected via the tail vein every other day for 10 days. The degree of renal damage and fibrosis was determined using histological assessment. The expression of collagen I, fibronectin, epithelial-mesenchymal transition markers, and Smad2/3 phosphorylation was examined by western blot analyses. Real-time PCR and enzyme-linked immunosorbent assay were performed in vivo to detect the levels of transforming growth factor (TGF)-ß1 and various growth factors. RESULTS: Telocytes attenuated renal fibrosis, as evidenced by reduced interstitial collagen accumulation, decreased expression of fibronectin and collagen I, upregulation of E-cadherin, and downregulation of α-smooth muscle actin. Furthermore, telocytes decreased serum TGF-ß1 levels, suppressed Smad2/3 phosphorylation, and increased the expression of hepatocyte growth factor (HGF) in rat kidney tissue following UUO. Blockage of HGF counteracted the protective effect of telocytes on UUO-treated kidneys. Through the detection of HGF mRNA levels in vitro, we found that telocytes had no effect on HGF expression compared with renal fibroblasts. CONCLUSION: Telocytes attenuated UUO-induced renal fibrosis in rats, likely through enhancing the expression of HGF in an indirect manner.

Endothelin Receptor Down-Regulation Mediated Ligand Regulation Mechanisms Protect Against Cellular Hypoxia Injury in Rat Vascular Endothelial Cells.

OBJECTIVE: Investigation of the effect of endothelin receptor A (ETaR)-targeting small interfering RNA (siRNA) on rat vascular endothelial cellular hypoxia injury, as well as its underlying mechanism. METHODS: An in vitro rat vascular smooth muscle cells - endothelial cells co-culture model was established and transfected with ETaR siRNA before hypoxia treatment. Cell culture supernatant, cellular protein and RNA were collected and examined at 0.5hrs, 1hrs, 2hrs, 4hrs, 8hrs, 16hrs, 24hrs and 48hrs of hypoxia with 1% oxygen. The time point at which the best silencing effect was achieved was chosen, eNOS inhibitor L-NAME was added, and post hypoxia cell culture supernatant, cellular protein and RNA was collected for further examination. RESULTS: After hypoxic treatment, endothelial-1 (ET-1) and ETaR expression levels gradually increased as oxygen deprivation extended. ET-1 and ETaR expression levels were significantly lower in the ETaR siRNA group compared with the Hypoxia group (P<0.001). Such difference peaked at 4hrs of hypoxia. ELISA examination of cell culture supernatant revealed that the amount of ET-1 and TGF-ßin the ETaR siRNA group were significantly lower compared to the Hypoxia group at all times, while the amount of NO and eNOS was higher. After 4 hrs of hypoxia, Smad2, Smad3, HIF-1, TNF-α, IFN-γ, IL-6, MCP-1, NF-κb, ET-1 and ANG II mRNA expression in endothelial cells and ETaR mRNA expression in A-10 cells of the ETaR siRNA group were lower than those of the Hypoxia siRNA group, while such results were much higher in the L-NAME group. Western Blot results showed lower expression of ETaR in the ETaR siRNA group compared with the hypoxia and negative siRNA groups, as well as significantly higher ETaR expression in the L-NAME group compared with the ETaR siRNA group. PI3K and p-AKT expression levels were mildly elevated after mild oxygen deprivation, and ETaR siRNA was able to enhance such elevation induced by hypoxia. In the L-NAME group, PI3K and p-AKT expression was much higher than the ETaR siRNA group. PKG and sGC expression levels significantly descended after mild oxygen deprivation. While such levels were higher in the ETaR siRNA group, compared with the hypoxia and negative siRNA groups, the L-NAME group had lower levels of PKG and sGC compared with the ETaR siRNA group. CONCLUSION: ETaR siRNA is capable of down-regulating the expression of inflammatory and transcription factors among endothelial cells treated with hypoxia. Down-regulation of ET-1 is triggered by altered nucleus transcription factor activity through the sGC/PKG signal pathway, and results in enhanced eNOS activity through the PI3K/Akt signal pathway. We suspect this to be the mechanism of the protective effect of ETaR siRNA.

Arsenic trioxide and sorafenib combination therapy for human hepatocellular carcinoma functions via up-regulation of TNF-related apoptosis-inducing ligand.

The survival benefits of sorafenib treatment for patients with hepatocellular carcinoma (HCC) are limited due to drug resistance and side effects. Therefore, combinations of sorafenib with other low toxicity drugs, including arsenic trioxide (As2O3) require investigation. The present study aimed to evaluate the potency of apoptosis-induction by As2O3/sorafenib treatment in HCC cell lines, Huh7, 97H and freshly-isolated HCC cells, and also to elucidate the underlying mechanism. A total of 10 patients with HCC were enrolled in the present study. Freshly-isolated HCC cells were purified from HCC tissues collected at surgery. HCC-cell apoptosis was measured by flow cytometry using proprium iodide/Annexin-V staining. The impacts of As2O3 and/or sorafenib on Huh7, 97H and fresh-isolated HCC-cell proliferation were evaluated by Cell Counting Kit-8 assay. The expression of TNF-related apoptosis-inducing ligand (TRAIL) was determined by reverse transcription-quantitative polymerase chain reaction and western blotting. The downregulation of TRAIL protein expression was achieved using small interfering RNA. The combination of As2O3 and sorafenib had anti-proliferative and pro-apoptotic effects in the liver cancer cell line, Huh7, via increased expression of TRAIL, but not in 97H cells. TRAIL-knockdown increased the drug-resistance of Huh7 cells. Freshly-isolated HCC cells were more sensitive to the As2O3 and sorafenib combination than the single drug treatments. Overall, the combination of As2O3 and sorafenib demonstrated potent anti-tumor activity in Huh7 and freshly-isolated HCC cells via a TRAIL-dependent pathway. This may be a potential therapeutic approach for advanced HCC treatment.

Baicalin ameliorates renal fibrosis via inhibition of transforming growth factor ß1 production and downstream signal transduction.

Previous studies have demonstrated the potential antifibrotic effects of baicalin in vitro, via examination of 21 compounds isolated from plants. However, its biological activity and underlying mechanisms of action in vivo remain to be elucidated. The present study aimed to evaluate the effect of baicalin on renal fibrosis in vivo, and the potential signaling pathways involved. A unilateral ureteral obstruction (UUO)­induced renal fibrosis model was established using Sprague­Dawley rats. Baicalin was administrated intraperitoneally every 2 days for 10 days. The degree of renal damage and fibrosis was investigated by histological assessment, and detection of fibronectin and collagen I mRNA expression levels. Epithelial­mesenchymal transition (EMT) markers, transforming growth factor-ß1 (TGF-ß1) levels and downstream phosphorylation of mothers against decapentaplegic 2/3 (Smad2/3) were examined in vivo and in an NRK­52E rat renal tubular cell line in vitro. Baicalin was demonstrated to markedly ameliorate renal fibrosis and suppress EMT, as evidenced by reduced interstitial collagen accumulation, decreased fibronectin and collagen I mRNA expression levels, upregulation of N­ and E­cadherin expression levels, and downregulation of α­smooth muscle actin and vimentin expression. Furthermore, baicalin decreased TGF­ß1 expression levels in serum and kidney tissue following UUO, and suppressed Smad2/3 phosphorylation in rat kidney tissue. In vitro studies identified that baicalin may inhibit the phosphorylation of Smad2/3 under the same TGF­ß1 concentration. In conclusion, baicalin may protect against renal fibrosis, potentially via inhibition of TGF­ß1 production and its downstream signal transduction.

Protective effects of cyclic helix B peptide on aristolochic acid induced acute kidney injury.

BACKGROUND: Aristolochic acid (AA) injuries remain a serious condition associated with acute renal dysfunction. Herein, the effect and mechanism of a novel tissue protective peptide, cyclic helical B-peptide (CHBP) derived from erythropoietin, were investigated in a mice model. METHODS: Mice were randomly divided into four groups, receiving the following treatments (1: saline; 2: AA 10mg/kg; 3: AA 10mg/kg +CHBP 4nmol/kg; 4: AA 10mg/kg +CHBP 8nmol/kg). RESULTS: Blood urea nitrogen and serum creatinine was increased by AA but decreased by CHBP in a dose-dependent fashion. CHBP also significantly improved renal tubular injury and inflammatory infiltration, which was gradually increased by AA. Apoptotic cells, infiltrating inflammatory cells, and active caspase-3+ cells were greatly reduced by CHBP. In addition, CHBP inhibited caspase-3, 9 and improved bcl-2, bcl-xl protein expression in vivo. CONCLUSION: Taken together, we demonstrated, for the first time, that CHBP effectively improved renal function and tissue damage caused by AA, which maybe through reducing caspase-3 activation, apoptosis, and inflammation.

Prediction of Renal Allograft Acute Rejection Using a Novel Non-Invasive Model Based on Acoustic Radiation Force Impulse.

Point shear wave elastography based on acoustic radiation force impulse is a novel technology used to quantify tissue stiffness by measuring shear wave speed. A total of 115 kidney transplantation recipients were consecutively enrolled in this prospective study. The patients were subdivided into two groups using 1 mo post-transplantation as the cutoff time for determining the development of acute rejection (AR). Shear wave speed was significantly higher in the AR group than in the non-AR group. We created a model called SEV, comprising shear wave speed, estimated glomerular filtration rate and kidney volume change, that could successfully discriminate patients with or without AR. The area under the receiver operating characteristic curve of SEV was 0.89, which was higher than values for other variables; it was even better in patients within 1 mo post-transplantation (0.954), but was lower than the estimated glomerular filtration rate in patients after 1 mo post-transplantation. Therefore, the SEV model may predict AR after renal transplantation with a high degree of accuracy, and it may be more useful in the early post-operative stage after renal transplantation.

Evaluation of kidney allograft status using novel ultrasonic technologies.

Early diagnosis of kidney allograft injury contributes to proper decisions regarding treatment strategy and promotes the long-term survival of both the recipients and the allografts. Although biopsy remains the gold standard, non-invasive methods of kidney allograft evaluation are required for clinical practice. Recently, novel ultrasonic technologies have been applied in the evaluation and diagnosis of kidney allograft status, including tissue elasticity quantification using acoustic radiation force impulse (ARFI) and contrast-enhanced ultrasonography (CEUS). In this review, we discuss current opinions on the application of ARFI and CEUS for evaluating kidney allograft function and their possible influencing factors, advantages and limitations. We also compare these two technologies with other non-invasive diagnostic methods, including nuclear medicine and radiology. While the role of novel non-invasive ultrasonic technologies in the assessment of kidney allografts requires further investigation, the use of such technologies remains highly promising.

The role of soluble fibrinogen-like protein 2 in transplantation: protection or damage.

Soluble fibrinogen-like protein 2 (sFGL2) is the soluble form of fibrinogen like protein 2. As a novel immunoregulatory molecule, sFGL2 is secreted mainly by T cells, especially regulatory T cells, and exerts an immunoregulatory property rather than a prothrombinase function in the immune system. sFGL2 changes not only the proliferation and differentiation of T cells but also the maturation of antigen presenting cells. Besides its innate and adaptive immunoregulatory functions, sFGL2 also induces apoptosis in cells including renal tubular epithelial cells through Fcγ receptors (FcγRs). It may affect transplantation via regulation of immunity and induction of apoptosis of different cells in a spatiotemporal manner. Here, we review the research progresses on sFGL2 including its structure, functions, and molecular mechanisms via which sFGL2 might affect organ transplantation, as well as discuss its characteristics and potential of becoming a therapeutic target in patients with rejection.