细胞因子抗瘢痕的研究进展

瘢痕是创伤修复的必然结果影响,瘢痕的产生,发展的因素很多,虽然国内外学者在病理性瘢痕领域研究取得了一些进展,但其确切的发病机制仍未完全清楚,目前对治疗瘢痕的研究主要集中在生化,细胞水平,对分子机制和基因水平的研究还在不断的深入,人们对细胞因子在瘢痕形成方面起了关键的调节作用这一观点已逐步形成共识,并将细胞因子引入瘢痕的治疗中.常见的细胞因子在抗瘢痕中的应用也将成为可能.本文主要介绍了常见细胞因子的在创面修复中的生物学特征及抗瘢痕的研究情况.     

有氧运动与干细胞动员的缺血心脏血管新生研究进展

有氧运动具有明确的血管新生效应,包括缺血心脏,但其机制尚未完全阐明。心肌梗死(MI)后冠脉微血管新生是心脏修复的前提。新近研究表明,血管新生来源于体内干/祖细胞的动员与参与,并以旁分泌效应影响内皮细胞(EC)功能及微血管分布效果,运动可以动员、激活内源性干细胞因子和血管生成因子的表达与分泌,并能从表观遗传学角度影响心脏血管新生。探索不同运动方式及强度对缺血心脏血管新生的作用及其分子机制,对缺血心脏的预防及术后康复具有重要意义。本文从心脏血管新生及其调控机制、自体干细胞动员参与缺血心脏的血管新生和运动通过干细胞动员促进缺血心脏血管新生等方面综述运动促进缺血心脏血管新生的主要机制、存在问题及相关研究进展。     

天然产物及复方药物抗皮肤瘢痕机制的研究进展

增生性瘢痕和瘢痕疙瘩是皮肤组织损伤后创面过度修复产生的一种常见疑难病。一些天然产物及复方药物中具有较好的抗皮肤瘢痕增生的成分。本文从皮肤瘢痕形成过程中的相关细胞成分、生长因子调节、细胞外基质、胶原代谢、微血管构筑、免疫调节等方面和水平综述天然产物及复方药物的作用机制的研究进展。     

白藜芦醇在创面修复中的作用

白藜芦醇(Resveratrol)是一种天然多酚类化合物,具有抗氧化、抗炎、促血管生成和细胞保护作用,是一种既能促进创面修复,又能防止慢性创面发展的可行治疗方法。该文介绍了白藜芦醇通过水凝胶、静电纺丝支架以及细菌纤维素聚合物等作用模式在各种细胞中发挥的抗氧化、抗炎、抗菌和抗衰老的特性,其诱导的分子途径,及与创面修复最相关的因素。对白藜芦醇在创面修复中存在问题及未来研究方向进行了展望。     

干细胞的旁分泌和自分泌功能——基础与临床研究的新视角

近年发现干细胞具有很强的旁/自分泌功能,本文综述干细胞所分泌的生长因子、细胞因子、调节肽、细胞信号分子等生物活性因子,以及缺血、缺氧、生长因子、性别和其它激素对干细胞分泌功能的调节;并分析干细胞分泌功能在血管生成、心脏、肝脏、肾脏和神经系统保护中的作用,认为干细胞可通过其分泌功能影响靶器官结构、功能状态及其病理状态下的修复,是干细胞治疗改善靶器官功能、抗凋亡、抗炎等作用的机制之一.     

睾丸间质干细胞的研究进展

睾丸间质干细胞(stem leydig cells,SLCs)是位于睾丸组织生精小管外侧壁的一类成体干细胞,具有维持自我更新和分化的特征。其分化形成的成熟间质细胞(adult leydig cells,ALCs)可以大量合成和分泌睾酮,是雄性动物机体睾酮产生的主要来源,广泛参与雄性动物的生殖和生理调控。由于SLCs发现较晚,在特异性标记及潜在调控机制和临床应用等方面的研究还并不深入。该文主要对SLCs的起源、分子标记、自我增殖和分化机制以及临床应用等进行综述,以促进SLCs研究和为雄性激素缺乏所引起疾病的临床应用奠定基础。     

肌卫星细胞激活和补给的分子调控与肌肉疾病

肌卫星细胞(muscle satellite cell,SC)作为生肌干细胞,参与司控生后骨骼肌的生长、修复和维持等重要过程.综述了NO-HGF,Myostatin,Notch等重要信号分子及卫星细胞自身的特殊微环境对SC激活和补给的分子调控机制,希冀将来可以从这两方面入手克服目前临床中肌卫星细胞移植治疗各种骨骼肌疾病的瓶颈.     

骨髓间充质干细胞体外趋化神经前体细胞的机制

骨髓间充质干细胞(BMSC)和神经前体细胞(NPC)移植于脑组织损伤动物的实验证明这两类细胞移植后均能在体内迁徙,与周围细胞整合,促进神经功能修复。BMSC促进神经功能修复的机制之一被认为与其分泌一些细胞因子和趋化因子有关,但具体机制不十分明确。为从基质细胞衍生因子-1α(SDF-1α)及其唯一的受体CXCR4这对分子相互作用的机制上探讨BMSC移植的可能治疗作用,实验采用ELISA法检测了体外培养的BMSC上清液中SDF-1α的含量,体外微孔隔离室迁移实验发现NPC能在BMSC分泌的培养上清液中SDF-1α的作用下发生定向迁移,特异性抗CXCR4单抗能有效阻断NPC的定向迁移效应,证实了BMSC分泌的SDF-1α促进表达CXCR4的NPC向病灶处迁移可能是促进神经功能修复的机制之一,从而为干细胞移植治疗神经功能缺损提供了一个新的思路。     

RNA干涉与干细胞

RNA干涉(RNAi)现象普遍存在于生物体细胞中,在理论上已清楚其分子机制,为干细胞研究提供了新的方法。现从RNAi的分子机制、干细胞中的RNAi现象、研究干细胞RNAi效应的方法以及小分子干涉RNA(siRNA)干涉干细胞特异功能基因的检测方法等方面进行了综述。表明应用RNAi技术研究基因功能和干细胞维持及定向分化的调控具有广阔的发展前景。     

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.