Uric Acid Induces Renal Inflammation via Activating Tubular NF-κB Signaling Pathway

Inflammation is a pathologic feature of hyperuricemia in clinical settings. However, the underlying mechanism remains unknown. Here, infiltration of T cells and macrophages were significantly increased in hyperuricemia mice kidneys. This infiltration of inflammatory cells was accompanied by an up-regulation of TNF-α, MCP-1 and RANTES expression. Further, infiltration was largely located in tubular interstitial spaces, suggesting a role for tubular cells in hyperuricemia-induced inflammation. In cultured tubular epithelial cells (NRK-52E), uric acid, probably transported via urate transporter, induced TNF-α, MCP-1 and RANTES mRNA as well as RANTES protein expression. Culture media of NRK-52E cells incubated with uric acid showed a chemo-attractive ability to recruit macrophage. Moreover uric acid activated NF-κB signaling. The uric acid-induced up-regulation of RANTES was blocked by SN 50, a specific NF-κB inhibitor. Activation of NF-κB signaling was also observed in tubule of hyperuricemia mice. These results suggest that uric acid induces renal inflammation via activation of NF-κB signaling

Beryl Mineralogy and Fluid Inclusion Constraints on the Be Enrichment in the Dakalasu No.1 Pegmatite, Altai, NW China

The Dakalasu No.1 pegmatitic rare-element deposit is a representative of Be-Nb-Ta pegmatites in Altai, Xinjiang, China. Beryl is the most important beryllium-carrying mineral in Dakalasu No.1 pegmatite. To constrain the concentration mechanism of Be, we conducted a study of the textural relationships and chemical compositions (major and trace elements) of beryl, along with microthermometry and Raman spectroscopy on beryl-hosted fluid inclusions. Two generations of beryl were recognized. The early beryl I was formed in the magmatic stage, whereas the late beryl IIa and IIb were formed in the magmatic-hydrothermal stage. Lithium and Cs contents increased from beryl I, beryl IIa, to beryl IIb, whereas Mg and Rb contents decreased. Scandium, V, and Ga contents of beryl IIa are similar to beryl IIb, but different in beryl I. Titanium is enriched in beryl IIa. The high FeO contents and Na/Cs ratios of beryl (I, IIa, and IIb) reveal the low degree of differentiation evolution of the Dakalasu No.1 pegmatite. Two types of melt inclusions and four types of fluid inclusions were identified in beryl IIa, IIb, and associated quartz. The microthermometry results indicated that beryl II is formed at 500 °C–700 °C, and 200 MPa–300 MPa. The Dakalasu No.1 pegmatite melt is enriched in volatiles, such as B, F, and CO2, evidenced by a large amount of tourmaline in the wall zone, the occurrence of a variety of tiny cryolite (Na3AlF6) inclusions, and CO2-rich fluid inclusions in beryl IIa. The enrichment mechanism of Be may be related to the crystallization of beryl at highly undercooled states of melt, and melt–melt–fluid immiscibility during the evolution and differentiation of the melt

A study of the immunoloregulation of double filtration plasmapheresis in maintenance hemodialysis patients with chronic hepatitis C.

Although a large number of drugs have been used to treat chronic hepatitis C (CHC), there still remains a great challenge to treat maintenance hemodialysis (MHD) patients with chronic hepatitis C. To clarify the immunnoloregulation of double filtration plasmapheresis (DFPP) in MHD patients with CHC, DFPP was performed in 20 MHD patients with CHC (HCV-antibody positive, serum HCV RNA >500 IU/ml more than 6 months and HCV genotype 1b). The clinical data was collected and peripheral blood mononuclear cells (PBMCs) were analyzed by flow cytometry at the time of hour 0, hour 3, day 3, day 7 and day 28 after the DFPP, respectively. Serum HCV particles could be removed partially by the DFPP. The titer of serum HCV RNA could remain in a lower level even 28 days after the treatment. Compared to MHD patients without HCV infection, the frequencies of innate immune cells were similar in MHD patients with CHC, while Th1/Th2 was elevated and the frequencies of regulatory T (Treg) cells were higher in those MHD patients with CHC. The frequencies of monocytes and natural killer (NK) cells remained after the DFPP in MHD patients with CHC. There were no significant changes of Th1, Th2 and Th1/Th2 in PBMC after DFPP. DFPP could reduce the frequencies of Th17 cells and Treg cells in PBMC from 7 days after DFPP in MHD patients with CHC. DFPP could partially remove the serum HCV particles mechanically. The titer of HCV RNA could remain in a lower level at least for 28 days probably due to the redistribution of the immunocytes in circulation

Beryl Mineralogy and Fluid Inclusion Constraints on the Be Enrichment in the Dakalasu No.1 Pegmatite, Altai, NW China

The Dakalasu No.1 pegmatitic rare-element deposit is a representative of Be-Nb-Ta pegmatites in Altai, Xinjiang, China. Beryl is the most important beryllium-carrying mineral in Dakalasu No.1 pegmatite. To constrain the concentration mechanism of Be, we conducted a study of the textural relationships and chemical compositions (major and trace elements) of beryl, along with microthermometry and Raman spectroscopy on beryl-hosted fluid inclusions. Two generations of beryl were recognized. The early beryl I was formed in the magmatic stage, whereas the late beryl IIa and IIb were formed in the magmatic-hydrothermal stage. Lithium and Cs contents increased from beryl I, beryl IIa, to beryl IIb, whereas Mg and Rb contents decreased. Scandium, V, and Ga contents of beryl IIa are similar to beryl IIb, but different in beryl I. Titanium is enriched in beryl IIa. The high FeO contents and Na/Cs ratios of beryl (I, IIa, and IIb) reveal the low degree of differentiation evolution of the Dakalasu No.1 pegmatite. Two types of melt inclusions and four types of fluid inclusions were identified in beryl IIa, IIb, and associated quartz. The microthermometry results indicated that beryl II is formed at 500 °C–700 °C, and 200 MPa–300 MPa. The Dakalasu No.1 pegmatite melt is enriched in volatiles, such as B, F, and CO2, evidenced by a large amount of tourmaline in the wall zone, the occurrence of a variety of tiny cryolite (Na3AlF6) inclusions, and CO2-rich fluid inclusions in beryl IIa. The enrichment mechanism of Be may be related to the crystallization of beryl at highly undercooled states of melt, and melt–melt–fluid immiscibility during the evolution and differentiation of the melt

Involvement of Endoplasmic Reticulum Stress in Albuminuria Induced Inflammasome Activation in Renal Proximal Tubular Cells

<div><p>Albuminuria contributes to the progression of tubulointerstitial fibrosis. Although it has been demonstrated that ongoing albuminuria leads to tubular injury manifested by the overexpression of numerous proinflammatory cytokines, the mechanism remains largely unknown. In this study, we found that the inflammasome activation which has been recognized as one of the cornerstones of intracellular surveillance system was associated with the severity of albuminuria in the renal biopsies specimens. In vitro, bovine serum albumin (BSA) could also induce the activation of NLRP3 inflammasome in the cultured kidney epithelial cells (NRK-52E). Since there was a significant overlap of NLRP3 with the ER marker calreticulin, the ER stress provoked by BSA seemed to play a crucial role in the activation of inflammasome. Here, we demonstrated that the chemical chaperone taurine-conjugated ursodeoxycholic acid (TUDCA) which was proved to be an enhancer for the adaptive capacity of ER could attenuate the inflammasome activation induced by albuminuria not only in vitro but also in diabetic nephropathy. Taken together, these data suggested that ER stress seemed to play an important role in albuminuria-induced inflammasome activation, elimination of ER stress via TUDCA might hold promise as a novel avenue for preventing inflammasome activation ameliorating kidney epithelial cells injury induced by albuminuria.</p></div

Ets-1 Targeted by MicroRNA-221 Regulates Angiotensin II-Induced Renal Fibroblast Activation and Fibrosis

Background: Fibroblast activation is one of the most important mechanisms for Angiotensin II (Ang II) in promoting renal fibrosis. Transcription factor Ets-1 is recognized to play a key role in kidney diseases. However, the role and mechanisms of Ets-1 in Ang-II induced fibroblast activation and kidney fibrosis are not fully understood. Methods: Mice were treated with Ang II via osmotic mini-pumps or Ang II expression plasmid (pAng II). Cultured normal rat kidney interstitial fibroblast (NRK-49F) cells were incubated with Ang II. Role of Ets-1 in renal fibrosis and fibroblast activation were assessed by Western blot, Immunohistochemical staining‚MTT, Boyden chamber and Immunofluorescence staining. Effects of miR-221 on Ets-1 and fibroblast activation were investigated by MTT, Boyden chamber, Western blot and Q-PCR. Results: We found that Ets-1 was up-regulated in fibrotic kidneys. Similarly, Ang II could activate NRK-49F cells as demonstrated by up-regulated α-SMA and fibronectin(FN) expression and enhanced cell proliferation and migration. Ang II also induced Ets-1 expression in NRK-49F cells in a dose and time dependent manner. Knock-down of Ets-1 by RNA interference attenuated Ang II-induced activation of NRK-49F cells. Ets-1 was previously reported as a target of microRNA-221 (miR-221). In Ang II-induced fibrotic kidney, miR-221 was down-regulated. Similar results were observed in Ang II treated NRK-49F cells. Ectopic expression of miR-221 mimic attenuated the up-regulation of Ets-1 by Ang II in NRK-49F cells, which further prevented the activation of NRK-49F cells. However, the inhibitor of miR-221 aggravated Ang II induced Ets-1 expression and NRK-49F cells activation. Conclusions: Our study suggests that miR-221/Ets-1 axis takes an important role in mediating AngII induced interstitial fibroblast activation and renal fibrosis

Circulatory mitochondrial DNA is a pro-inflammatory agent in maintenance hemodialysis patients.

Chronic inflammation is highly prevalent in maintenance hemodialysis (MHD) patients, and it has been shown to be a strong predictor of morbidity and mortality. Mitochondrial DNA (mtDNA) released into circulation after cell damage can promote inflammation in patients and animal models. However, the role and mechanisms of circulatory mtDNA in chronic inflammation in MHD patients remain unknown. Sixty MHD patients and 20 health controls were enrolled in this study. The circulatory mtDNA was detected by quantitative real-time PCR assay. Plasma interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) were quantitated by ELISA assay. Dialysis systems in MHD patients and in vitro were used to evaluate the effect of different dialysis patterns on circulatory mtDNA. Circulatory mtDNA was elevated in MHD patients comparing to that of health control. Regression analysis demonstrated that plasma mtDNA was positively associated with TNF-α and the product of serum calcium and phosphorus, while negatively associated with hemoglobin and serum albumin in MHD patients. MtDNA induced the secretion of IL-6 and TNF-α in the THP-1 cells. Single high-flux hemodialysis (HF-HD) and on line hemodiafiltration (OL-HDF) but not low-flux hemodialysis (LF-HD) could partially reduce plasma mtDNA in MHD patients. In vitro, both HD and hemofiltration (HF) could fractional remove mtDNA. Collectively, circulatory mtDNA is elevated and its level is closely correlated with chronic inflammation in MHD patients. HF-HD and HDF can partially reduce circulatory mtDNA in MHD patients

TUDCA attenuates the inflammasome activation induced by BSA in NRK-52E cells in vitro.

<p>A, B and C: Western blot analysis shows TUDCA attenuates the caspase-1 activation and maturation of IL-1β and IL-18 protein induced by BSA in NRK-52E cells. Growth arrested NRK-52E cells were pretreated without (same amount of DMSO) or with 100 umol/L TUDCA for 0.5 hours, and then followed by incubation without or with 5 mg/ml BSA for 12 hours as indicated. C, D and E: Graphic presentation showed the relative abundance of caspase-1, IL-1β and IL-18 protein after normalization with α-tubulin in various groups. Data are presented as mean±SEM of three independent experiments. *<i>P</i><0.05 vs. normal control; # <i>P</i><0.05 vs. group with BSA treatment.</p

Bovine serum albumin induced endoplasmic reticulum stress in NRK-52E cells.

<p>A. Western blot analysis shows the expression of GRP78 and the phosphorylation of eIF2a in NRK-52E cells after treatment without or with 5 mg/ml BSA for various time periods in serum-free medium. The whole cell lysate was immunoblotted with GRP78, phosphorylated- eIF2α and eIF2α antibody, respectively. The same blot was reprobed with α-tubulin to confirm equal loading of each lane. B. Western blot analysis shows the expression of GRP78 and the phosphorylation of eIF2a in NRK-52E cells without or with different amounts of BSA for 12 h in serum-free medium. C and D: Graphical presentation shows the relative abundances of GRP78 after normalization with α-tubulin and the phosphorylation of eIF2α after normalization with eIF2α. Data are presented as mean±SEM of three independent experiments. *<i>P</i><0.05 vs. normal control (the relative abundance of GRP78 protein level); # P<0.05 vs. normal control (the phosphorylation of eIF2α).</p

Bovine serum albumin induced the inflammasome activation in NRK-52E cells in vitro.

<p>A,C and E: Western blot analysis shows the caspase-1 activation and maturation of IL-1β and IL-18 protein in NRK-52E cells after treatment without or with 5 mg/ml BSA for various time periods in serum-free medium. The whole cell lysate was immunoblotted with caspase-1, IL-1β and IL-18 antibody, respectively. The same blot was reprobed with α-tubulin to confirm equal loading of each lane. B, D and F: Western blot analysis shows the caspase-1 activation and maturation of IL-1β and IL-18 protein in NRK-52E cells without or with different amounts of BSA for 12 h in serum-free medium. The whole cell lysate was also immunoblotted with caspase-1, IL-1β and IL-18 antibody, respectively. G through I: The inflammasome markers were detected by an indirect immunostaining in NRK-52E cells. NRK-52E cells were treated without (left column) or with 5 mg/ml BSA (right column) for 24 hours in serum-free medium. G: Immunostaining of caspase-1; H: Immunostaining of IL-1β; I: Immunostaining of IL-18.</p