特异性双链RNA对小鼠干细胞和转基因荧光蛋白的抑制作用

目的 研究特异性dsRNA对小鼠ES细胞中对核外基因和核内染色体基因的干扰作用，并对RNA干扰(RNAi)技术在皮肤病基因治疗领域中应用的可能性进行初步探讨。方法 选择荧光蛋白基因为靶基因，通过质粒或RNA直接转染技术，将荧光蛋白双链RNA(dsRNA—EGFP)转染小鼠胚胎干细胞(ES细胞)，从而观察该细胞中特异性RNAi作用。并通过皮肤局部注射dsRNA—EGFP和局部外用脂质体包裹的dsRNA—EGFP。观察EGFP转基因鼠皮肤EGFP的表达。结果 无论是转染质粒产生的dsRNA—EGFP或是直接转染的dsRNA—EGFP，均明显抑制ES细胞核外或染色体中EGFP基因的特异性表达。局部皮肤注射或皮肤外用脂质体-dsRNA—EGFP均特异性抑制EGFP转基因鼠皮肤EGFP的表达。结论 本研究证实了小鼠ES细胞中特异性RNAi的作用。     

氨基糖甙类体外抑制人表皮角质形成细胞tRNA的生物合成过程

病原体对抗生素逐步增长的耐药现象以及缺乏强效的抗菌药成为感染性疾病治疗中的主要问题，因而有必要进一步了解抗生素在分子水平上的作用机制。以往的证据表明RNA是抗细菌和抗病毒药作用的关键靶点，而氨基糖甙类抗生素除了可以抑制病原体的核糖体功能，抑制蛋白质合成，还有报道可干扰各种RNA分子并在体外能抑制人角质形成细胞的增殖。     

溶瘤病毒介导RNA干扰治疗肿瘤的进展

RNA干扰是一种由双链RNA介导的基因沉默现象,是目前简单而高效的阻断哺乳动物细胞内特异基因表达的最有效方法　.溶瘤病毒是一类仅在肿瘤细胞内特异增殖的病毒载体,通过其介导的小干扰RNA不仅可以靶向肿瘤细胞,随着病毒在肿瘤细胞内的复制而加强RNA干扰介导的癌基因沉默效果.因此,溶瘤病毒介导的RNA干扰模式开辟肿瘤基因治疗的新途径.     

RNA干扰对系统性硬化病皮肤成纤维细胞结缔组织生长因子表达的影响

目的 研究RNA干扰对系统性硬化病(SS)皮肤成纤维细胞结缔组织生长因子(CTGF)mRNA和蛋白表达水平的影响.方法 设计4个针对CTGF的特异性小干扰RNA(siRNA)及一个非特异性siRNA.体外转录获得siRNA,将siRNA用6-羧基荧光素(FAM)标记后瞬时转染至原代培养的SS患者皮肤成纤维细胞;转染48h后,以RT-PCR及蛋白印迹法分别检测CTGF mRNA及蛋白量的变化.结果 转染了4个特异性siRNA的成纤维细胞中CTGF mRNA水平均有不同程度下调(P<0.001),抑制效果由强至弱为,siRNA742>siRNA828>siRNA578>siRNA948.蛋白印迹则显示有3个siRNA能使CTGF蛋白表达水平不同程度下调(P<0.001),其中siRNA742的抑制效应最强.结论 RNA干扰能显著抑制SS成纤维细胞CTGF的表达.     

RNA干扰与皮肤恶性肿瘤的治疗

RNA干扰(RNA interference,RNAi)是在转录水平上的基因阻断技术,可以抑制靶基因表达或使基因沉默。促成针对性的RNAi发生,达到在不同环节上调节恶性肿瘤发生、发展,影响基因的表达,是RNAi参与皮肤恶性肿瘤治疗的重要思路。使用RNAi技术参与肿瘤的治疗具有针对性强、效率高、作用可以持久的优势,可能特异性、长期及完全抑制目的基因表达、逆转肿瘤细胞恶性表型、诱导肿瘤细胞发生调亡和降低肿瘤耐药性,从而实现抑制肿瘤发生、抑制肿瘤生长、抑制肿瘤侵袭性、逆转肿瘤耐药性,达到治疗肿瘤的目的。     

卷曲蛋白受体小干扰RNA对瘢痕疙瘩形成影响的体外研究

目的 :探讨RNA干扰技术(RNAi)靶向抑制卷曲蛋白(Frizzled)受体对人瘢痕疙瘩成纤维细胞(KFB)的抑制作用。方法:将针对人Frizzled受体基因设计合成的3对特异性小干扰RNA(si RNA)分别转染体外培养的人KFB,通过实时荧光定量聚合酶链式反应(q PCR)和western blot筛选出干扰人KFB Frizzled受体基因表达的最佳si RNA,进而转染人KFB,并采用q PCR及western blot检测Frizzled受体及相关基因和蛋白表达;采用细胞增殖检测试剂(CCK)-8检测细胞增殖情况。结果:si RNA303具有最佳的Frizzled受体m RNA和蛋白质抑制效率,Frizzled受体si RNA转染后,KFB的Frizzled受体、Wnt2、糖原合酶激酶(GSK)3β和D型细胞周期蛋白(cyclin D)1 m RNA及蛋白表达均下降。p-GSK3β蛋白表达下降,KFB生长受抑制程度增大,增殖减慢,且随着培养时间的延长,细胞倍增时间明显延迟。结论:转染靶向Frizzled受体的si RNA可有效敲低该基因在KFB内的表达,从而抑制成纤维细胞增殖。     

RNA干预：一项防治艾滋病的新策略

RNA干预是普遍存在于动植物细胞内的一种高度序列特异性的抗病毒体系。由于HIV—1是RNA逆转录病毒，近几年来，越来越多的研究发现，利用RNA干预技术，将模拟细胞表面受体或HIV—1基因序列的双链RNA成分导入靶细胞，可有效抑制HIV—1的入侵、复制和表达，为防治艾滋病提供了新途径。     

短发卡RNA对人黑素瘤细胞BRAF基因的沉默作用

目的构建BRAF基因序列特异性的短发卡RNA(shRNA)质粒载体,检测其对人黑素瘤细胞BRAF基因的干扰作用。方法设计2条BRAF基因序列特异性的shRNA编码序列和1条非特异性阴性对照序列,插入质粒pGenesil-1,双酶切和测序鉴定。用构建成功的3条质粒转染人黑素瘤细胞株A375和M14,分别采用RT-PCR和蛋白印迹检测其BRAF基因的mRNA和蛋白表达。结果所设计的shRNA序列被正确插入质粒pGenesil-1。非特异性对照质粒neg对黑素瘤细胞BRAF基因表达不产生干扰,2条序列特异性质粒braf1和braf2抑制了BRAF基因mRNA和蛋白的表达,其中braf1干扰效果最为明显,最高抑制率可达90%。结论质粒介导的shRNA可成功干扰人黑素瘤细胞BRAF基因的表达,其抑制时间可持续至少1个月。     

RNA干预:一项防治艾滋病的新策略

RNA干预是普遍存在于动植物细胞内的一种高度序列特异性的抗病毒体系。由于HIV-1是RNA逆转录病毒,近几年来,越来越多的研究发现,利用RNA干预技术,将模拟细胞表面受体或HIV-1基因序列的双链RNA成分导入靶细胞,可有效抑制HIV-1的入侵、复制和表达,为防治艾滋病提供了新途径。     

小干预RNA在某些病毒性疾病的研究现状

小干预RNA是新近发现的能高效性、特异性剪切同源mRNA的短双链RNA。其强大的基因抑制功能可望用于抗病毒与抗肿瘤的治疗和生物基因功能的研究中。文中就其作用机制、生物学作用及在某些病毒性疾病中的研究现状与临床应用的可能性作一综述     

New fillers for the new man

ABSTRACT:  Two new collagen-based lidocaine-containing dermal fillers, ArteSense™/ArteFill™ (Artes Medical, San Diego, CA) and Evolence® (Colbar LifeScience Ltd., Herzliya, Israel), have proved to be of particular interest to men, many of whom seek a long-lasting or permanent correction. ArteFill™ has been available in the United States since 2006, and it is expected that Evolence® will reach the American market in 2008. The properties of the two products will be described, and experience based on the administration of many hundreds of syringes of both products by a Canadian dermatologist will be detailed here, with tips and precautions to optimize patient outcomes.     

Outcomes and adverse effects of ablative vs nonablative lasers for skin resurfacing: A systematic review of 1093 patients

It is generally believed that ablative laser therapies result in prolonged healing and greater adverse events when compared with nonablative lasers for skin resurfacing. To evaluate the efficacy of ablative laser use for skin resurfacing and adverse events as a consequence of treatment in comparison to other modalities, a PRISMA‐compliant systematic review (Systematic Review Registration Number: 204016) of twelve electronic databases was conducted for the terms “ablative laser” and “skin resurfacing” from March 2002 until July 2020. Studies included meta‐analyses, randomized control trials, cohort studies, and case reports to facilitate evaluation of the data. All articles were evaluated for bias. The search strategy produced 34 studies. Of 1093 patients included in the studies of interest, adverse events were reported in a total of 106 patients (9.7%). Higher rates of adverse events were described in nonablative therapies (12.2% ± 2.19%, 31 events) when compared with ablative therapy (8.28% ± 2.46%, 81 events). 147 patients (13.4%) reported no side effects, 68 (6.22%) reported expected, transient self‐resolving events, and five (0.046%) presented with hypertrophic scarring. Excluding transient events, ablative lasers had fewer complications overall when compared with nonablative lasers (2.56% ± 2.19% vs 7.48% ± 3.29%). This systematic review suggests ablative laser use for skin resurfacing is a safe and effective modality to treat a range of pathologies from photodamage and acne scars to hidradenitis suppurativa and posttraumatic scarring from basal cell carcinoma excision. Further studies are needed, but these results suggest that ablative lasers are a superior, safe, and effective modality to treat damaged skin.     

Genetic alterations in RAS‐regulated pathway in acral lentiginous melanoma

Studies integrating clinicopathological and genetic features have revealed distinct patterns of genomic aberrations in Melanoma. Distributions of BRAF or NRAS mutations and gains of several oncogenes differ among melanoma subgroups, while 9p21 deletions are found in all melanoma subtypes. In the study, status of genes involved in cell cycle progression and apoptosis was evaluated in a panel of 17 frozen primary acral melanomas. NRAS mutations were found in 17% of the tumors. In contrast, BRAF mutations were not found. Gains of AURKA gene (20q13.3) were detected in 37.5% of samples, gains of CCND1 gene (11q13) or TERT gene (5p15.33) in 31.2% and gains of NRAS gene (1p13.2) in 25%. Alterations in 9p21 were identified in 69% of tumors. Gains of 11q13 and 20q13 were mutually exclusive, and 1p13.2 gain was associated with 5p15.33. Our findings showed that alterations in RAS‐related pathways are present in 87.5% of acral lentiginous melanomas.     

Self‐resolving superficial primary cutaneous mucormycosis in a 7‐week‐old infant

A 7‐week‐old girl, born at 30 weeks' gestational age, presented to clinic for evaluation of a crop of vesicular lesions that were noted after removal of a bandage that had been in place for 4 days. A punch biopsy of the lesion revealed fungal elements that were later identified as Rhizopus spp. The lesion began to self‐resolve, and no further treatment was needed, with full resolution of the lesion by 1 month after presentation. Clinicians should be aware of the variable presentations of mucormycosis and consider fungal infection in the differential diagnosis when evaluating vulnerable patients with skin eruptions.     

Pathogenic role of IL-17 in psoriasis and psoriatic arthritis

Psoriasis is a chronic inflammatory skin disorder resulting from a complex network of cytokines and chemokines produced by various immune cell types and tissue cells. Emerging evidence suggests a central role of IL-17 and IL-23/T17 axis in the pathogenesis of psoriasis, giving a rationale for using IL-17-blocking agents as therapeutics.Three agents targeting IL-17 signaling are being studied in Phase III clinical trials: secukinumab and ixekizumab (IL-17 neutralizing agents), and brodalumab (IL-17 receptor antagonist). Preliminary results are highly promising for all anti-IL17 agents, creating fair expectations on this class of agents as the new effective therapeutic approach for the treatment of psoriasis.