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ABSTRACT: Nephrin, a structural molecule, is also a signaling molecule after phosphorylation. Inhibition of nephrin phosphorylation is correlated with podocyte injury. The PINCH-1-ILK-α-parvin (PIP) complex plays a crucial role in cell adhesion and cytoskeleton formation. We hypothesized that nephrin phosphorylation influenced cytoskeleton and cell adhesion in podocytes by regulating the PIP complex. The nephrin phosphorylation, PIP complex formation, and F-actin in Wistar rats intraperitoneally injected with puromycin aminonucleoside were gradually decreased but increased with time, coinciding with the recovery from glomerular/podocyte injury and proteinuria. In cultured podocytes, PIP complex knockdown resulted in cytoskeleton reorganization and decreased cell adhesion and spreading. Nephrin and its phosphorylation were unaffected after PIP complex knockdown. Furthermore, inhibition of nephrin phosphorylation suppressed PIP complex expression, disorganized podocyte cytoskeleton, and decreased cell adhesion and spreading. These findings indicate that alterations in nephrin phosphorylation disorganize podocyte cytoskeleton and decrease cell adhesion through a PIP complex-dependent mechanism. [BMB Reports 2013; 46(4): 230-235].
BMB reports 04/2013; 46(4):230-5. · 1.72 Impact Factor
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ABSTRACT: Nephrin, an important structural and signal molecule of podocyte slit-diaphragm (SD), has been suggested to contribute to the angiotensin II (Ang II)-induced podocyte injury. Caveolin-1 has been demonstrated to play a crucial role in signaling transduction. In the present study, we evaluated the role of caveolin-1 in Ang II-induced nephrin phosphorylation in podocytes. Wistar rats-receiving either Ang II (400 ng/kg/min) or normal saline (via subcutaneous osmotic mini-pumps, control) were administered either vehicle or telmisartan (3 mg/kg/min) for 14 or 28 days. Blood pressure, 24-hour urinary albumin and serum biochemical profile were measured at the end of the experimental period. Renal histomorphology was evaluated through light and electron microscopy. In vitro, cultured murine podocytes were exposed to Ang II (10(-6)M) pretreated with or without losartan (10(-5) M) for variable time periods. Nephrin and caveolin-1 expression and their phosphorylation were analyzed by Western-blotting and immunofluorescence. Caveolar membrane fractions were isolated by sucrose density gradient centrifugation, and then the distribution and interactions between Ang II type 1 receptor (AT1), nephrin, C-terminal Src kinase (Csk) and caveolin-1 were evaluated using Western-blotting and co-immunoprecipitation. Podocyte apoptosis was evaluated by cell nucleus staining with Hoechst-33342. Ang II-receiving rats displayed diminished phosphorylation of nephrin but enhanced glomerular/podocyte injury and proteinuria when compared to control rats. Under control conditions, podocyte displayed expression of caveolin-1 in abundance but only a low level of phospho moiety. Nonetheless, Ang II stimulated caveolin-1 phosphorylation without any change in total protein expression. Nephrin and caveolin-1 were co-localized in caveolae fractions. AT1 receptors and Csk were moved to caveolae fractions and had an interaction with caveolin-1 after the stimulation with Ang II. Transfection of caveolin-1 plasmid (pEGFPC3-cav-1) significantly increased Ang II-induced nephrin dephosphorylation and podocyte apoptosis. Furthermore, knockdown of caveolin-1 expression (using siRNA) inhibited nephrin dephosphorylation and prevented Ang II-induced podocyte apoptosis. These findings indicate that Ang II induces nephrin dephosphorylation and podocyte injury through a caveolin-1-dependent mechanism.
Cellular signalling 02/2012; 24(2):443-50. · 4.09 Impact Factor
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ABSTRACT: To develop an HPLC method for determination of gallic acid, hydroxysafflor yellow A, cinnamic aldehyde and piperine in Tibetan medicine Dangzuo, and to compare the content of four active components in Dangzuo of different Tibetan regions.
The separation was carried out on a Waters XTerra RP-C18 column ( 4.6 mm x 250 mm, 5 microm). The mobile phases were methanol and water, all contained 0.1% glacial acetic acid, for gradient elution. The gradient program was as follows: 0-22.5 min, methanol was changed from 5% to 50%; 22.5-40 min, changed to 80% 80:20. The flow rate was 1.0 mL x min(-1). The detection wavelength was 270 nm. The reference wavelength was 500 nm.
The linear ranges of gallic acid, hydroxysafflor yellow A, cinnamic aldehyde and piperine were 0.040-0.640 microg (r = 0.999 8), 0.090-1.440 microg (r = 0.999 9), 0.031-0.500 microg (r = 0.999 9 ) and 0.092-41.477 microg (r = 0.998 9), respectively. The average recoveries (n = 6) were 97.42% (RSD 1.9%), 97.55% (RSD 2.9%), 98.69% (RSD 0.96%) and 96.72% (RSD 4.0%), respectively. The content ranges of gallic acid, hydroxysafflor yellow A, cinnamic aldehyde and piperine in Dangzuo samples of different Tibetan regions were 0.11341.69 mg x g(-1), 0.889-1.51 mg x g(-1), 0.000-40.606 mg x g(-1) and 1.96-2.73 mg x g(-1), respectively.
The method is a simple and effective for quality control of Tibetan medicine Dangzuo.
Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica 04/2011; 36(8):1046-9.
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ABSTRACT: To study the heat processing technics of Nanhanshuishi.
To find the best processing technic, the single factor experiments and orthogonal experiments were designed basing on the processing technics summarized by consulting documents, scriptures and investigating some Tibetan hospitals, meanwhile, the content of Ca, Fe, Mn, Zn, and Cu in the processed Nanhanshuishi in single factor experiments and orthogonal experiments were detected.
The best processing technic of Nanhanshuishi was as follows: Nanhanshuishi was crashed to 10-20 mm in diameter, the ratio of the weight of Aconiti Kusnezoffii Radix and potassium nitrate was 1: 2, and the boiling time was 3 h.
The work in this article provided a basic processing technic data for clarifying the mechanism of processing and establishing the perfect processing technics of Nanhanshuishi.
Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica 03/2011; 36(6):683-6.
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ABSTRACT: To determine the composition, structure, trace elements and thermal stability of Tibetan medicine Nanhanshuishi.
The trace elements, the structure, and the thermal stability of Nanhanshuishi were assayed and calculated by X-ray fluorescence spectrometry (XRF), inductively coupled plasma optical emission spectrometer (ICP-OES), atomic fluorescence spectrometry (AFS), inductively coupled plasma mass spectrometry (ICP-MS), X-ray power diffraction (XRD), TG-DTA.
The results indicated that the phase is mainly made up of CaCO3 (Rhombohedral, R-3c) in Nanhanshuishi. The analysis of elements show that Nanhanshuishi is rich in Ca and O, and contains other more than 20 minor elements, such as Si, Mg, Fe, Al, Na, K, Zn, Mn, Pb, As, Hg etc. The result of TG-DTA show that the weight of Nanhanshuishi starts to decline from near 700 degrees C and get steady above 850 degrees C.
The study provided scientific data for the establishment of quality standards of Tibetan medicine Nanhanshuishi.
Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica 03/2011; 36(6):691-3.
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ABSTRACT: To investigate the effect of oxidized low density lipoprotein receptor-1 (LOX-1) on tubular epithelial-mesenchymal transition (TEMT) induced by oxidized low-density lipoprotein (ox-LDL) and its mechanism.
NRK-52E cells were incubated with ox-LDL (0, 25, 50, and 100 μg/ml) for 24 hours or pre-treated with the chemical inhibitor of the LOX-1 receptor polyinosinic acid (poly I) and carrageenan or the antioxidant N-acetyl-L-cysteine (NAC), the cells were then exposed to 50 μg/ml of ox-LDL.The expression of LOX-I, E-cadherin, α-smooth muscle actin (α-SMA) and reactive oxygen species (ROS) were analyzed by real-time PCR, western blotting analysis, immunofluorescence and confocal laser scanning microscopy.
Ox-LDL increased the expression of LOX-1 mRNA and protein in a dose-dependent manner from 0 to 100 μg/ml (P < 0.05). Following the increase in the LOX-1 protein level, the lipid intake, ROS generation and α-SMA expression increased; however, the E-cadherin level decreased. The pre-treatment with poly I or carrageenan or NAC significantly inhibited the LOX-1 expression, α-SMA expression, the lipid intake and ROS generation and reversed decrease of E-cadherin expression induced by ox-LDL. Meanwhile, the ROS generation were associated with a increase in the LOX-1 expression. The α-SMA expression was positively correlated with the ROS generation and LOX-1 expression, and the E-cadherin expression was negatively correlated with the ROS generation and LOX-1 expression.
LOX-1 and ROS may play a important role in epithelial-mesenchymal transition of NRK52E induced by OX-LDL.
Lipids in Health and Disease 10/2010; 9:120. · 2.17 Impact Factor
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ABSTRACT: Swertia mussotii Franch. (SM) (Gentianaceae) was a traditional Tibetan folk herb for hepatitis in the Qinghai-Tibet plateau areas. For understanding the hepatoprotection and toxicity characteristics of Swertia mussotii Franch., the whole plant of Swertia mussotii was extracted by water (SME-b) and 75% ethanol (SME-a); then, SME-a was dissolved with water, the supernatant was SME-c, and the sedimentation was SME-d. 17.76% SME-a, 14.48% SME-b, 10.13% SME-c, and 4.35%SME-d were extracted from Swertia mussotii. These four extracts were evaluated with acute toxicity and hepatoprotective effect on CCl 4 -induced acute liver damage in mice. The toxic material mainly reside in SME-c and SME-a. The hepatoprotective materials were in SME-a, SME-c and SME-d, while SME-b had no hepatoprotective activities. So, SME-a and SME-c had both the hepatoprotection and toxicity characteristics; SME-b had no toxicity or the hepatoprotection characteristics; only SME-d was hepatoprotective function without toxicity, which could be a good candidate for new drug healing the live disorder.
Journal of Medicinal Plants Research. 05/2010; 4:706-709.
