Obestatin对血浆ghrelin和nesfatin-1水平及胃排空的影响

目的:探讨侧脑室注射obestatin对大鼠血浆酰基化ghrelin、去酰基化ghrelin、nesfatin-1水平的影响以及对胃排空的调控。方法:侧脑室注射obestatin,采用酶免疫测定(EIA)法检测血浆酰基化ghrelin、去酰基化ghrelin、nesfatin-1水平以及胃排空率的变化。结果:侧脑室分别注射0.1、0.3或1.0 nmol obestatin,大鼠血浆酰基化ghrelin、去酰基化ghrelin以及nesfatin-1水平无显著改变(P0.05),且酰基化ghrelin与去酰基化ghrelin比率无显著改变(P0.05);侧脑室注射obestatin,大鼠摄食量无显著改变,但胃排空率明显增加(P0.05);胃排空率明显延迟(P0.05)。与侧脑室注射1.0 nmol Obestatin组相比,注射1.0 nmol Obestatin+CRF,大鼠摄食量无显著改变,胃排空率明显延迟(P0.05)。各组摄食量及进入十二指肠内食物量无明显差异(P0.05)。结论:中枢obestatin促进大鼠的胃排空,可能与h/r CRF通路有关。     

NUCB2/nesfatin-1对小鼠摄食行为的调控及机制

目的:探讨NUCB2/nesfatin-1对小鼠摄食行为的调控及机制。方法:利用侧脑室埋管,免疫组化染色等方法,探讨侧脑室和外周注射nesfatin-1对小鼠摄食行为的影响。结果:侧脑室注射不同剂量nesfatin-1(0.3μg,1μg,3μg),注药后4 h夜间进食量明显减少,且呈显著剂量依赖关系(t=2.61~4.78,P0.05~0.01),侧脑室注射3μg nesfatin-1,小鼠前3小时累积摄食量明显降低(t=8.69~10.73,P0.01),且持续降低12小时(t=2.64,P0.05),同时餐间间隔时间明显延长(t=2.66,P0.05),每分钟/1-4 h进食量明显降低(t=2.63,P0.05),且进食每克食物所用时间明显增加(t=3.02,P0.05)。在下丘脑弓状核,外侧区和背内侧核均有NUCB2/nesfatin-1免疫阳性神经元表达。皮下或腹腔注射nesfatin-1,小鼠进食量和进食行为均无显著改变(P0.05)。结论:中枢nesfatin-1可抑制小鼠摄食行为。     

侧脑室注射orexin-A对大鼠昼夜摄食的影响

目的:探讨侧脑室注射orexin-A对大鼠昼夜摄食的影响。方法:将Wistar大鼠随机分组,采用单剂量侧脑室注射和连续侧脑室注射以及外周注射法,分别于日间和夜间给药,测量大鼠24小时内各阶段的摄食量以及相应生化指标。结果:在光照期间,侧脑室微量注射orexin-A,大鼠4小时内摄食量显著增加(P0.05),且呈剂量依赖关系(P0.05)。在夜间初期(18:00)侧脑室注射orexin-A,大鼠食物摄入量无显著差异(P0.05)。但在中午12:00给予侧脑室注射orexin-A,注射后4小时内大鼠摄食量显著高于NS对照组(P0.05)。连续8日给予orexin-A侧脑室注射,可使注射后日间摄食量显著增加(P0.05),而夜间摄食量显著减少(P0.05),但24小时内总的摄食量不变(P0.05)。orexin-A并未改变棕色脂肪组织温度、末梢血糖、血浆瘦素等指标的水平。结论:orexin-A对大鼠摄食的调节具有昼夜节律性。     

Nesfatin-1对营养性肥胖大鼠摄食量体重和胃排空率的影响（英文）

目的:通过颈静脉注射外源性nesfatin-1,观察营养性肥胖大鼠摄食、体重、胃排空率的变化情况。方法:营养性肥胖大鼠造模成功后,各组大鼠行颈静脉插管手术,术后所有大鼠分为四组,正常对照组及肥胖对照组大鼠注射0.9%生理盐水,正常给药及肥胖给药组大鼠注射外源性nesfatin-1(100μg·kg-1),连续颈静脉给药7 d,期间记录各组大鼠摄食量以及体重,给药结束后采用灌胃酚红法测定大鼠胃排空率。结果:用高脂饲料连续饲养大鼠7天,正常对照组和正常nesfatin-1组大鼠的Lee’s指数分别为314.22和314.44,肥胖对照组和肥胖nesfatin-1组大鼠的Lee’s指数分别为318.22和319.03,肥胖差异显著(T-test,P0.01),造模成功。连续给药7 d后,给药组摄食量和体重与对照组相比明显降低,但肥胖给药组摄食量及体重下降较正常给药组更加明显。胃排空率与胃排出酚红量是成负相关的,实验中正常对照组和正常给药组的胃排空率分别是64.71±4.51和46.47±3.20,而肥胖对照组和肥胖给药组大鼠的胃排空率分别是75.67±2.47和50.88±3.07,因此高剂量给予nesfatin-1能显著降低大鼠的胃排空率。结论:综上所述,长期持续外周静脉给予外源性的nesfatin-1可以明显抑制正常及肥胖大鼠的摄食,动物体重减轻。     

糖尿病大鼠ghrelin和nesfatin-1表达动力学及其调控

目的:探讨STZ诱导糖尿病大鼠ghrelin和nesfatin-1动力学及分泌调节变化。方法:STZ诱导糖尿病大鼠模型;采用葡糖糖脱氢酶分析法测量血浆葡萄糖水平;免疫放射分析检测血浆ghrelin、nesfatin-1、胰岛素、胰岛素样生长因子1(IGF-1)、生长激素(GH)含量;采用real-time PCR检测ghrelin m RNA水平变化;免疫组化观察ghrelin和nesfatin-1免疫活性细胞数量。结果:糖尿病大鼠体重显著降低(t=23.16,P<0.01),血糖水平显著升高(t=22.55,P<0.01),血浆胰岛素和IGF-1水平显著降低(t=6.50,t=24.13,P<0.01),但GH水平显著升高(t=3.30,P<0.05)。糖尿病大鼠血浆总ghrelin(t=7.03,P<0.01)和活性ghrelin(t=3.33,P<0.05)水平均显著升高,血浆nesfatin-1水平则显著降低(t=6.24,P<0.01);糖尿病大鼠血浆总ghrelin与GH(r=0.81,P<0.01)和IGF-1水平(r=-0.58,P<0.01)呈显著相关性;与对照组大鼠相比,糖尿病大鼠胃总ghrelin(t=16.86,P<0.01)和活性ghrelin(t=3.30,P<0.05)水平均显著降低;而胃nesfatin-1(t=7.93,P<0.01)水平则显著升高。胃总ghrelin水平与血浆IGF-1水平呈明显相关性(r=0.65,P<0.01);与对照组大鼠相比,糖尿病大鼠胃ghrelin m RNA表达水平显著升高(t=16.8,P<0.01),胃底ghrelin免疫活性细胞数量显著减少(t=3.98,P<0.01);实验中给予大鼠自由饮食,糖尿病大鼠血浆总ghrelin水平显著增加(t=7.53,P<0.01),nesfatin-1水平显著降低(t=5.46,P<0.01)。糖尿病大鼠注射胰岛素后,可使增加的ghrelin水平(t=1.76,P=0.11)和降低的nesfatin-1水平接近正常(t=1.96,P=0.06);且胰岛素可显著反转糖尿病大鼠胃总ghrelin(t=8.54,P<0.01)和nesfatin-1水平(t=2.42,P<0.05);以及注射胰岛素后,糖尿病大鼠胃底ghrelin细胞显著增加,nesfatin-1细胞明显减少(t=3.21,t=2.59,P<0.05)。结论:Ghrelin或nesfatin-1参与糖尿病大鼠能量平衡调控。     

Nesfatin-1 对营养性肥胖大鼠摄食量体重和胃排空率的影响

目的：通过颈静脉注射外源性nesfatin-1,观察营养性肥胖大鼠摄食、体重、胃排空率的变化情况。方法：营养性肥胖大鼠造模 成功后,各组大鼠行颈静脉插管手术,术后所有大鼠分为四组,正常对照组及肥胖对照组大鼠注射0.9%生理盐水,正常给药及肥 胖给药组大鼠注射外源性nesfatin-1（100 滋g·kg-1）,连续颈静脉给药7 d,期间记录各组大鼠摄食量以及体重,给药结束后采用灌 胃酚红法测定大鼠胃排空率。结果：用高脂饲料连续饲养大鼠7天,正常对照组和正常nesfatin-1组大鼠的Lee’s指数分别为314.22 和314.44,肥胖对照组和肥胖nesfatin-1 组大鼠的Lee’s指数分别为318.22 和319.03,肥胖差异显著(T-test, P<0.01),造模成功。连 续给药7 d 后,给药组摄食量和体重与对照组相比明显降低,但肥胖给药组摄食量及体重下降较正常给药组更加明显。胃排空率 与胃排出酚红量是成负相关的,实验中正常对照组和正常给药组的胃排空率分别是64.71± 4.51 和46.47± 3.20,而肥胖对照组和 肥胖给药组大鼠的胃排空率分别是75.67± 2.47 和50.88± 3.07,因此高剂量给予nesfatin-1 能显著降低大鼠的胃排空率。结论：综 上所述,长期持续外周静脉给予外源性的nesfatin-1 可以明显抑制正常及肥胖大鼠的摄食,动物体重减轻。     

侧脑室注射Orexins对大鼠摄食的影响及机制

目的:探讨侧脑室注射orexins(食欲素)、NPY(神经肽Y)、MCH(黑色素聚集激素)和甘丙肽对大鼠摄食的影响及其机制。方法:将成年雄性Wistar大鼠随机分为对照组、侧脑室注射组和室旁核(PVN)注射组。通过套管将orexin-A、orexin-B、NPY、MCH和甘丙肽分别注射至侧脑室和PVN内,随后测量大鼠食物摄入量,并检测PVN、弓状核(ARC)和VMH内c-fos的表达。结果:与对照组比较,侧脑室注射NPY、MCH和orexin-B 2 h后,大鼠摄食量显著增多(P0.05)。相较于orexin-B和MCH,NPY对摄食的影响更显著(P0.05)。与NS对照组比较,侧脑室注射甘丙肽和orexin-A 1 h后,大鼠摄食量显著增多(P0.05)。与NS对照组比较,侧脑室注射orexin-A可显著增加c-fos在PVN和ARC中的表达,在VMH中效应较弱(P0.05)。与NS对照组比较,PVN注射NPY能显著增加大鼠2 h摄食量(P0.05),PVN注射orexin-A能显著增加大鼠2 h和4 h摄食量(P0.05)。结论:orexins与可促进大鼠摄食,此效应可能通过下丘脑参与摄食调控中枢PVN和ARC而实现的。     

第四脑室注射orexin-A及OX1R拮抗剂对大鼠摄食及自由活动的影响

本文旨在探讨第四脑室注射orexin-A及orexin 1型受体(orexin-1 receptor,OX1R)拮抗剂SB334867对肥胖和正常大鼠摄食和自由活动的影响。采用高脂饲料诱导建立肥胖大鼠模型,分别在肥胖和正常大鼠第四脑室注射不同剂量orexin-A或SB334867,观察光照和黑暗环境下两种大鼠0~4 h摄食量及活动量的变化。结果显示,第四脑室注射不同剂量orexin-A,光照条件下,正常和肥胖大鼠0~4 h摄食量和活动量均较生理盐水对照组明显增加,呈剂量依赖关系(P0.05~0.01);且肥胖大鼠摄食量和活动量显著高于正常大鼠;黑暗条件下,不同剂量的orexin-A对正常和肥胖大鼠摄食量和活动量均没有明显改变(P0.05)。第四脑室注射不同剂量SB334867,光照条件下,正常和肥胖大鼠0~2 h,2~4 h摄食量和活动量均较生理盐水对照组明显减少(P0.05);且肥胖大鼠摄食量和活动量均显著高于正常大鼠;黑暗条件下,正常和肥胖大鼠摄食量和活动量均没有明显改变(P0.05)。以上结果提示,第四脑室周核团可能是orexin-A及OX1R作用靶点之一;光照条件对orexin-A和OX1R生理功能的发挥可能具有重要影响。     

下丘脑Nesfatin-1抑食效应及机制研究

目的:探讨下丘脑nesfatin-1与组胺信号通路间的相互作用及对摄食的影响。方法:采用第三脑室置管、药物注射、免疫组化、ELISA等方法,观察氟甲基组氨酸(FMH)、α螺旋促肾上腺皮质激素释放激素(CRH)和促甲状腺激素释放激素(TRH)对Nesfatin-1诱导的抑制摄食的影响,以及Nesfatin-1与组胺信号通路相互影响调控摄食机制。结果:第三脑室注射nesfatin-1可显著减少大鼠摄食量,而第三脑室内预先注射FMH,nesfatin-1抑制摄食效应明显减弱,但FMH本身并不影响大鼠夜间摄食量。第三脑室注射nesfatin-1,可显著增加优降宁诱发的PVN、腹内侧核(VMH)、结节乳头核(TMN)内t-MH的积累;但腹腔注射nesfatin-1没有引起大鼠摄食改变,t-MH蓄积也无显著变化。第三脑室注射α螺旋CRH或抗TRH血清均可显著减弱nesfatin-1的抑食效应,而α螺旋CRH、抗TRH血清本身并不显著影响大鼠摄食量。第三脑室注射nesfatin-1可显著增加下丘脑PVN内CRH和TRH水平,且nesfatin-1可显著增加优降宁诱导的PVN、VMH和TMN内t-MH的表达,而α螺旋CRH或抗TRH血清可显著抑制nesfatin-1诱导的PVN、VMH和TMH内t-MH的蓄积。第三脑室注射组胺可显著增加大鼠下丘脑PVN内nesfatin-1含量,但LH、VMH、TMN以及血浆内nesfatin-1水平无显著改变。免疫组化研究显示,PVN内有nesfatin-1和H1-R免疫反应阳性神经元,且部分神经元共存。结论:Nesfatin-1的抑食效应可能与下丘脑组胺信号通路介导。     

下丘脑腹内侧核损毁对大鼠nesfatin-1/NUCB2表达的影响

目的:观察下丘脑腹内侧核(VMH)损毁对大鼠脂肪组织nesfatin-1/NUCB2表达的影响及其机制。方法:电损毁VMH,观察大鼠体重和脂肪组织变化,采用Western blot检测脂肪组织中nesfatin-1/NUCB2表达改变。腹腔注射6-羟多巴胺(50 mg/kg)以阻断交感神经;持续外周注射卡巴胆碱(180μg/kg)用以模拟VMH损毁,观察其对大鼠皮下脂肪nesfatin-1/NUCB2表达的影响。结果:与对照组和假手术组比较,VMH损毁后大鼠体重明显增加(P0.05),皮下脂肪(P0.05)和肠系膜脂肪(P0.05)也显著增多;Western blot分析结果显示,nesfatin-1/NUCB2在胰腺和肝脏中表达较多,但皮下、肠系膜脂肪和肩胛间棕色脂肪组织(i BAT)中表达较少,骨骼肌(腓肠肌)中鲜有表达;与对照组和假手术组比较,VMH损毁组大鼠nesfatin-1/NUCB2在肝脏、胰腺、骨骼肌和i BAT中表达无显著差异(P0.05),皮下脂肪(P0.05)和肠系膜脂肪(P0.05)nesfatin-1/NUCB2表达显著增多与对照组相比,6-羟多巴胺组nesfatin-1/NUCB2表达显著升高(t=3.43,P0.05),而卡巴胆碱组nesfatin-1/NUCB2表达无显著差异(t=0.37,P=0.72)。结论:VMH损毁后大鼠脂肪组织nesfatin-1/NUCB2表达改变可能通过抑制交感神经活动介导。     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.