It has been demonstrated that neuronal nitric oxide synthase (nNOS) negatively regulates adult neurogenesis. However, the cellular and molecular mechanisms underlying are poorly understood. Here, we show that nNOS from neural stem cells (NSCs) and from neurons play opposite role in regulating neurogenesis. The NSCs treated with nNOS inhibitor N 5 -(1-imino-3-butenyl)-L-ornithine (L-VNIO) or nNOS gene deletion exhibited significantly decreased proliferation and neuronal differentiation, indicating that NSCs-derived nNOS is essential for neurogenesis. The NSCs cocultured with neurons displayed a significantly decreased proliferation, and deleting nNOS gene in neurons or scavenging extracellular nitric oxide (NO) abolished the effects of coculture, suggesting that neurons-derived nNOS, a source of exogenous NO for NSCs, exerts a negative control on neurogenesis. Indeed, the NSCs exposed to NO donor DETA/NONOate displayed decreased proliferation and neuronal differentiation. The bidirectional regulation of neurogenesis by NSCs-and neurons-derived nNOS is probably related to their distinct subcellular localizations, mainly in nuclei for NSCs and in cytoplasm for neurons. Both L-VNIO and DETA/NONOate inhibited telomerase activity and proliferation in wild-type (WT) but not in nNOS 2/2 NSCs, suggesting a nNOS-telomerase signaling in neurogenesis. The NSCs exposed to DETA/NONOate exhibited reduced cAMP response element binding protein (CREB) phosphorylation, nNOS expression, and proliferation. The effects of DETA/NONOate were reversed by forskolin, an activator of CREB signaling. Moreover, disrupting CREB phosphorylation by H-89 or LV-CREB133-GFP simulated the effects of DETA/NONOate, and inhibited telomerase activity. Thus, we conclude that NSCs-derived nNOS stimulates neurogenesis via activating telomerase, whereas neurons-derived nNOS represses neurogenesis by supplying exogenous NO that hinders CREB activation, in turn, reduces nNOS expression in NSCs.

Increased HHLA2 expression was observed in ccRCC tumour tissue, which leads to a remarkable shorter overall survival and poorer prognosis. Together with other molecular evidence, we have demonstrated that HHLA2 could be a potential prognostic biomarker for ccRCC.

Background: Renal ischemia-reperfusion (I/R) injury is a major cause of acute renal failure (ARF). The transcription factor nuclear factor-κB (NF-κB) has been implicated as a key mediator of reperfusion injury. Activation of NF-κB is dependent upon the phosphorylation of its inhibitor, IκB, by the specific inhibitory κB kinase (IKK) subunit, IKKβ. We hypothesized that ischemic preconditioning (IPC) reduces acute renal damage following I/R injury by inhibiting activation of IKKβ. As neutrophil gelatinase-associated lipocalin (NGAL), an early predictive biomarker of acute kidney injury, is regulated by NF-κB, we approached the relationship between NGAL and IKKβ. Method: Thirty male Sprague-Dawley rats were randomly divided into 3 groups after right kidney nephrectomy. Group A rats were sham-operated controls. Group B rats were 45-min ischemic in the left renal artery while Group C rats were pre-treated with 3 cycles of 2-min ischemia and 5-min reperfusion. All the rats were sacrificed at 24 h after reperfusion. We harvested kidneys and serum to do further analysis, including histological and functional parameters, expressions of NGAL and IKKβ in renal tissues. Results: Compared with rats subjected to I/R injury, pre-treated rats had a significant decrease in serum creatinine level (Scr) and tubulointerstitial injury scores (Scr, 86.79 ± 12.98 vs. 205.89 ± 19.16 μmol/l, p < 0.01; tubulointerstitial injury scores, 1.3 ± 0.48 vs. 3.8 ± 0.79, p < 0.01). In addition, expressions of IKKβ (0.95 ± 0.21 vs. 1.74 ± 0.17, p < 0.05) and NGAL (1.71 ± 0.032 vs. 2.66 ± 0.078, p < 0.05) at renal tubule in pre-treated rats were attenuated significantly compared with rats subjected to ischemia-reperfusion injury. Moreover, our study showed that IKKβ and NGAL were in positive correlation (R = 0.965 > R_0.01(30) = 0.448, p < 0.01). Conclusions: The evidence suggests that IKKβ may play a role in renal I/R injury and give rise to the generation of NGAL. It appears that IPC may attenuate renal injury and the expression of NGAL following acute I/R injury. IKKβ may offer a clinically accessible target for preventing renal injury following I/R.

The transcription factor NF-κB has been found critical to the pathogenesis of renal ischemia-reperfusion injury, which is a major cause of acute kidney injury (AKI). Activation of NF-κB is dependent upon the activation of the specific inhibitory κB kinase (IKK) subunit IKKβ. Here, we investigate whether small interfering RNA (siRNA) targeting IKKβ protects rats from renal ischemia- reperfusion injury in vivo. Renal ischemia-reperfusion injury was induced by clamping the renal artery for 45 min. Rats were treated before ischemia with IKKβ siRNA or scrambled siRNA, administered by renal artery injection. Treated animals were evaluated for renal IKKβ protein and mRNA expression, blood biochemistry, tissue histopathology, NF-κB/DNA binding activity, and expression of two downstream inflammatory cytokines, neutrophil gelatinase-associated lipocalin (NGAL) and IL-18. A local injection of IKKβ siRNA resulted in inhibition of renal IKKβ gene expression, NF-κB/DNA binding activity, and expression of NGAL and IL-18. Rats pretreated with IKKβ siRNA had significantly less blood urea nitrogen and serum creatinine levels and less renal tubular damage scores. Consequently, our data confirm that targeted silencing of IKKβ using siRNA substantially diminishes kidney injury and inflammation following ischemia-reperfusion.

c Adenovirus (Ad) cell attachment is initiated by the attachment of the fiber protein to a primary receptor (usually CAR or CD46). This event is followed by the engagement of the penton base protein with a secondary receptor (integrin) via its loop region, which contains an Arg-Gly-Asp (RGD) motif, to trigger virus internalization. To understand the well-orchestrated adenovirus cell attachment process that involves the fiber and the penton base, we reconstructed the structure of an Ad5F35 capsid, comprising an adenovirus type 5 (Ad5) capsid pseudotyped with an Ad35 fiber, at a resolution of approximately 4.2 Å. The fiber-penton base interaction in the cryo-electron microscopic (cryo-EM) structure of Ad5F35 is similar to that in the cryo-EM structure of Ad5, indicating that the fiber-penton base interaction of adenovirus is conserved. Our structure also confirms that the C-terminal segment of the fiber tail domain constitutes the bottom trunk of the fiber shaft. Based on the conserved fiber-penton base interaction, we have proposed a model for the interaction of Ad5F35 with its primary and secondary receptors. This model could provide insight for designing adenovirus gene delivery vectors. Human adenoviruses (Ads) are nonenveloped, double-stranded DNA viruses and are responsible for respiratory, gastrointestinal, and ocular infections. In addition, Ads have demonstrated great potential as vaccine vectors (7,13,22). Ad has a large, complex, icosahedral capsid with a diameter of ϳ920 Å, not including the elongated homotrimeric fibers at each of its 5-fold vertices. The Ad capsid is composed of three major proteins: 240 hexon trimers that form the 20 facets of the icosahedral capsid, 12 penton bases, and 12 fiber trimers at the 12 icosahedral vertices (8, 36). A structure of Ad5F35, comprising an adenovirus type 5 (Ad5) capsid pseudotyped with an Ad35 fiber (25, 35), has been determined at 6-Å resolution (33). Combined with secondary structure prediction for minor proteins, the 6-Å structure has enabled the precise locations of minor proteins IIIa, VI, VIII, and IX to be determined (33). The locations of these minor proteins have been further confirmed by two nearly atomic resolution Ad structural analyses: the Ad5 structure analyzed by cryoelectron microscopy (cryo-EM) and the Ad5F35 structure determined using X-ray crystallography (17, 30). The minor capsid proteins, including IIIa, VIII, and IX, are thought to form proteinprotein networks to enhance the stability of the Ad capsid (17).The Ad fiber, which is formed by three copies of fiber proteins, plays a role in the initial attachment of the Ad capsid to the host cell surface through its interaction with the cellular receptor. Although Ad fibers are of various lengths depending on the serotype, the fiber proteins of all serotypes share an overall architecture: an N-terminal tail domain that interacts with the pentameric penton base, a C-terminal globular knob domain that functions as the attachment site for the host cell receptors, and a central shaft domain th...