Blood and bones: Osteoblastic HIF signaling regulates erythropoiesis

Comment on: Rankin EB, et al. Cell 2012; 149:63-74.     

Polarization and Filter Properties Investigation of Metal Gratings and Rings

We demonstrated the near-field optical transmission properties of nanogratings with spoke and rings structures through a near-field scanning optical microscope, and the far-field optical transmission properties with different polarization angles are investigated with an optical microscope. Our experimental results verified the polarization properties of the nanograting structures and further demonstrated the experimental results are supported by the finite difference time domain theoretical simulation. The optical microscope imaging of the spoke and ring structures also show that the grating structures can disperse visible light of different wavelengths.     

Deletion of Smad3 protects against C-reactive protein-induced renal fibrosis and inflammation in obstructive nephropathy

Introduction and Aims: Elevated plasma levels of C-reactive protein (CRP) are closely associated with progressive renal injury in patients with chronic kidney disease (CKD). Here, we tested a hypothesis that CRP may promote renal fibrosis and inflammation via a TGF-β/Smad3-dependent mechanism.Methods: Role and mechanisms of TGF-β/Smad3 in CRP-induced renal fibrosis and inflammation were examined in a mouse model of unilateral ureteral obstruction (UUO) induced in CRP Tg/Smad3 KO mice and in a rat tubular epithelial cell line in which Smad3 gene is stably knocked down (S3KD-NRK52E).Results: We found that mice overexpressing the human CRP gene were largely promoted renal inflammation and fibrosis as evidenced by increasing IL-1β, TNF-α, MCP-1 expression, F4/80⁺ macrophages infiltration, and marked accumulation of α-smooth muscle actin (α-SMA), collagen I and fibronectin in the UUO kidney, which were blunted when Smad3 gene was deleted in CRPtg-Smad3KO. Mechanistically, we found that the protection of renal inflammation and fibrosis in the UUO kidney of CRPtg-Smad3KO mice was associated with the inactivation of CD32-NF-κB and TGF-β/Smad3 signaling.Conclusion: In conclusion, Smad3 deficiency protects against CRP-mediated renal inflammation and fibrosis in the UUO kidney by inactivating CD32-NF-κB and TGF-β/Smad3 signaling.     

New findings on nuclear gangliosides: overview on metabolism and function

Dopamine (DA) is an important transmitter in both motor and limbic pathways. We sought to investigate the role of D(1)-receptor activation in axonal DA release regulation in dorsal striatum using a D(1)-receptor antagonist, SKF-83566. Evoked DA release was monitored in rat striatal slices using fast-scan cyclic voltammetry. SKF-83566 caused a concentration-dependent increase in peak single-pulse evoked extracellular DA concentration, with a maximum increase of ～ 65% in 5 μM SKF-83566. This was accompanied by a concentration-dependent increase in extracellular DA concentration clearance time. Both effects were occluded by nomifensine (1 μM), a dopamine transporter (DAT) inhibitor, suggesting that SKF-83566 acted via the DAT. We tested this by examining [(3)H]DA uptake into LLc-PK cells expressing rat DAT, and confirmed that SKF-83566 is a competitive DAT inhibitor with an IC(50) of 5.7 μM. Binding studies with [(3)H]CFT, a cocaine analog, showed even more potent action of SKF-83566 at the DAT cocaine binding site (IC(50) = 0.51 μM). Thus, data obtained using SKF-83566 as a D(1) DA-receptor antagonist may be confounded by concurrent DAT inhibition. More positively, however, SKF-83566 might be a candidate to attenuate cocaine effects in vivo because of the greater potency of this drug at the cocaine versus DA binding site of the DAT.     

Chemokine receptor CCR5 functionally couples to inhibitory G proteins and undergoes desensitization

Chemokine receptor CCR5 is not only essential for chemotaxis of leukocytes but also has been shown to be a key coreceptor for HIV-1 infection. In the present study, hemagglutinin epitope-tagged human CCR5 receptor was stably expressed in Chinese hamster ovary cells or transiently expressed in NG108–15 cells to investigate CCR5-mediated signaling events. The surface expression of CCR5 was confirmed by flow cytometry analysis. The CCR5 agonist RANTES stimulated [³⁵S]GTPγS binding to the cell membranes and induced inhibition on adenylyl cyclase activity in cells expressing CCR5. The effects of RANTES were CCR5 dependent and could be blocked by pertussis toxin. Furthermore, overexpression of Giα2 strongly increased both RANTES-dependent G-protein activation and inhibition on adenylyl cyclase in cells cotransfected with CCR5. These data demonstrated directly that activation of CCR5 stimulated membrane-associated inhibitory G proteins and indicated that CCR5 could functionally couple to G-protein subtype Giα2. The abilities of CCR5 to activate G protein and to inhibit cellular cAMP accumulation were significantly diminished after a brief prechallenge with RANTES, showing rapid desensitization of the receptor-mediated responsiveness. Prolonged exposure of the cells to RANTES caused significant reduction of surface CCR5 as measured by flow cytometry, indicative of agonist-dependent receptor internalization. Our data thus demonstrated that CCR5 functionally couples to membrane-associated inhibitory G proteins and undergoes agonist-dependent desensitization and internalization. J. Cell. Biochem. 71:36–45, 1998. © 1998 Wiley-Liss, Inc.     

An Ultralong Lifespan and Low‐Temperature Workable Sodium‐Ion Full Battery for Stationary Energy Storage

Presently, commercialization of sodium‐ion batteries (SIBs) is still hindered by the relatively poor energy‐storage performance. In addition, low‐temperature (low‐T) Na storage is another principal concern for the wide application of SIBs. Unfortunately, the Na‐transfer kinetics is extremely sluggish at low‐T, as a result, there are few reports on low‐T SIBs. Here, an advanced low‐T sodium‐ion full battery (SIFB) assembled by an anode of 3D Se/graphene composite and a high‐voltage cathode (Na₃V₂(PO₄)₂O₂F) is developed, exhibiting ultralong lifespan (over even 15 000 cycles, the capacity retention is still up to 86.3% at 1 A g^?1), outstanding low‐T energy storage performance (e.g., all values of capacity retention are >75% after 1000 cycles at temperatures from 25 to ?25 °C at 0.4 A g^?1), and high‐energy/power properties. Such ultralong lifespan signifies that the developed sodium‐ion full battery can be used for longer than 60 years, if batteries charge/discharge once a day and 80% capacity retention is the standard of battery life. As a result, the present study not only promotes the practicability and commercialization of SIBs but also points out the new developing directions of next‐generation energy storage for wider range applications.     

不同生态环境对蒲公英超氧物歧化酶（SOD）的影响

选择干生,湿生,阳生,阴生四种生境中生长的蒲公英Taraxacum mongolicum Hand.-Mazz分根,叶,花分别测定了SOD活性和比活性,并比较了同工酶谱的变化情况,结果表明不同生境未能改变SOD的同工酶条带数,但对其活性大小有影响,这种影响尤其表现在根上,湿生和阴生根的SOD活性明显高于干生和阳生根的SOD活性,显示出蒲公英的不同器官适应不同的环境效应。     

细叶益母草(Leonurus sibiricus)叶表面腺毛多样性及发育形态学研究

本文研究了分布在细叶益母草（Ｌｅｏｎｕｒｕｓｓｉｂｉｒｉｃｕｓ） 叶表面三种腺毛的发育过程,在此基础上,对２细胞头状腺毛、４细胞头状腺毛和８细胞盾状腺毛的多样性特征进行了讨论