Honokiol attenuates mitochondrial fission and cell apoptosis by activating Sirt3 in intracerebral hemorrhage

Background:Sirtuin-3(Sirt3)has been documented to protect against mitochondrial dysfunction and apoptosis.Honokiol(HKL)is a Sirt3 pharmacological activator with reported neuroprotective effects in multiple neurological disorders.The present study aimed to explore the neuroprotective effects of HKL and the role of Sirt3 following intracerebral hemorrhage(ICH).Methods:An in vivo ICH model in rats was established by injecting autologous blood into the right basal ganglia.PC12 cells were stimulated with hemin.For the in vivo investigation,the modified Neurological Severity Scores and the Morris water maze test were performed to assess neurological deficits.Hematoxylin-Eosin and Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining were employed to evaluate the histopathology and apoptosis.Immunohistochemical staining was used to investigate the expression of Sirt3.Adenosine triphosphate(ATP)levels were quantified to assess mitochondrial dysfunction.Cell counting kit-8,lactate dehydrogenase assay,and flow cytometry were used to analyze cell vitality and apoptosis in vitro.Immunofluorescence staining was performed to observe mitochondrial morphology and dynamin-related protein 1(Drp1)localization to mitochondria.Western blot was applied to quantify the expression of Sirt3,Bax,Bcl-2,cleaved-caspase-3,Drp1,phosphorylation of Drp1 at serine-616,and phosphorylation of Drp1 at serine-637 in vivo and in vitro.Results:HKL treatment alleviated neurological deficits,attenuated the histopathological damage and cell apoptosis,and restored the decreased ATP levels in ICH rats.HKL improved cell survival rate,reduced cell apoptosis,and inhibited mitochondrial fission in PC12 cells.Moreover,both in vivo and in vitro models showed increased phosphorylation of Drp1 at Ser616,and reduced phosphorylation of Drp1 at Ser637.Meanwhile,immunofluorescence co-localization analysis revealed that hemin increased the overlap of Drp1 and mitochondria in PC12 cells.The phosphorylation and mitochondrial translocation of Drp1 were effectively reversed by HKL treatment.Importantly,the selective Sirt3 inhibitor 3-(1H-1,2,3-triazol-4-yl)pyridine suppressed these effects.Conclusion:Our findings demonstrated that HKL ameliorated ICH-induced apoptosis and mitochondrial fission by Sirt3,suggesting that HKL has immense prospects for the treatment of ICH.

CRISPR/Cas9技术编辑OsRhoGDI2基因导致水稻半矮化

OsRhoGDI2是通过酵母双杂交从水稻幼穗中分离的一个与Rho蛋白家族成员OsRacD相互作用蛋白的编码基因,但功能尚不明确。本研究利用CRISPR/Cas9技术创制水稻OsRhoGDI2基因敲除突变体。检测结果表明,转基因水稻T0代获得2种纯合突变体,T1代获得8种纯合突变体。序列分析显示,在敲除水稻中,该基因的编辑靶点附近发生了碱基的替换或缺失,预期生成丧失RhoGDI保守结构域的截短蛋白。表型比对分析发现,敲除水稻与对照相比,株高显著降低,统计学分析结果显示,敲除水稻株高降低源于第Ⅱ和第Ⅲ茎节的缩短,提示OsRhoGDI2基因可能与水稻株高控制相关。

A ratiometric benzothiazole-based fluorescence probe for selectively recognizing HClO and its practical applications

A ratiometric probe(HBT-HBZ)bearing 2-hydrazino benzothiazole and 3-(benzo[d]thiazol-2-yl)-2-hydroxy-5-methylbenzaldehyde for sensing hypochlorous acid(HClO)with high selectivity and sensitivity is reported in this article.The fluorescence intensity ratios(I470nm/I572nm)of the probe with different concentrations of analyte showed excellent selectivity and a linear response to minor changes in HClO.The detection limit of 24 nmol/L suggests that the sensor is very sensitive to HClO.According to the series of performed experiments,HBT-HBZ has practical applications,such as the detection of HClO residues in tap water,which has been rarely reported.In addition,confocal laser microscopy experiments confirmed that HBT-HBZ can selectively recognize HClO in HeLa cells.A ratiometric probe(HBT-HBZ)for sensing HClO with high selectivity and sensitivity is reported in this article.The probe exhibited high selectivity for HClO among other ROS,RNS and anions.In addition,HBTHBZ has some practical applications such as the analysis of the HClO content in tap water.Furthermore,confocal fluorescence microscopy imaging showed that HBT-HBZ can be applied for detecting HClO in living cells.

2080 nm long-wavelength, high-power dissipative soliton resonance in a dumbbell-shaped thulium-doped fiber laser

We demonstrate a 2080 nm long-wavelength mode-locked thulium(Tm)-doped fiber laser operating in the dissipative soliton resonance(DSR) regime. The compact all-fiber dumbbell-shaped laser is simply constructed by a 50/50 fiber loop mirror(FLM), a 10/90 FLM, and a piece of large-gain Tm-doped double-clad fiber pumped by a 793 nm laser diode. The 10/90 FLM is not only used as an output mirror, but also acts as a periodical saturable absorber for initiating DSR mode locking. The stable DSR pulses are generated at the center wavelength as long as 2080.4 nm, and the pulse duration can be tunable from 780 to 3240 ps as the pump power is increased. The maximum average output power is 1.27 W, corresponding to a pulse energy of 290 nJ and a nearly constant peak power of 93 W. This is, to the best of our knowledge, the longest wavelength for DSR operation in a mode-locked fiber laser.

212-kHz-linewidth,transform-limited pulses from a single-frequency Q-switched fiber laser based on a few-layer Bi_2Se_3 saturable absorber

Conventional Q-switched fiber lasers operating at multi-longitudinal-mode oscillation usually suffer from selfmode-locking-induced temporal instability, relatively strong noise, and low coherence. Here, we address the challenge through demonstrating, for the first time, to the best of our knowledge, a single-longitudinal-mode(SLM)Er-doped fiber(EDF) laser passively Q-switched by a few-layer Bi_2Se_3 saturable absorber(SA). The Bi_2Se_3 SA prepared by the liquid-phase exfoliation method shows a modulation depth of ～5% and saturation optical intensity of 1.8 MW∕cm^2. A section of 1-m unpumped EDF together with a 0.06-nm-bandwidth fiber Bragg grating is used as an ultra-narrow autotracking filter to realize SLM oscillation. Stable SLM Q-switching operation at 1.55 μm is successfully achieved with the spectral linewidth as narrow as 212 kHz and the pulse duration of2.54 μs, manifesting near-transform-limited pulses with a time-bandwidth product of 0.53. In particular, we found that the SLM Q-switching possesses the higher signal-to-noise ratios of 62 dB(optical) and 48 dB(radio frequency), exhibiting its advantages of low noise and high stability. Such an SLM Q-switched fiber laser could gain great interest for some applications in coherent detection, coherent optical communications, and high-sensitivity optical sensing.