Long noncoding RNA X-inactive specific transcript regulates NLR family pyrin domain containing 3/caspase-1-mediated pyroptosis in diabetic nephropathy

BACKGROUND NLRP3-mediated pyroptosis is recognized as an essential modulator of renal disease pathology.Long noncoding RNAs(lncRNAs)are active participators of diabetic nephropathy(DN).X inactive specific transcript(XIST)expression has been reported to be elevated in the serum of DN patients.AIM To evaluate the mechanism of lncRNA XIST in renal tubular epithelial cell(RTEC)pyroptosis in DN.METHODS A DN rat model was established through streptozotocin injection,and XIST was knocked down by tail vein injection of the lentivirus LV sh-XIST.Renal metabolic and biochemical indices were detected,and pathological changes in the renal tissue were assessed.The expression of indicators related to inflammation and pyroptosis was also detected.High glucose(HG)was used to treat HK2 cells,and cell viability and lactate dehydrogenase(LDH)activity were detected after silencing XIST.The subcellular localization and downstream mechanism of XIST were investigated.Finally,a rescue experiment was carried out to verify that XIST regulates NLR family pyrin domain containing 3(NLRP3)/caspase-1-mediated RTEC pyroptosis through the microRNA-15-5p(miR-15b-5p)/Toll-like receptor 4(TLR4)axis.RESULTS XIST was highly expressed in the DN models.XIST silencing improved renal metabolism and biochemical indices and mitigated renal injury.The expression of inflammation and pyroptosis indicators was significantly increased in DN rats and HG-treated HK2 cells;cell viability was decreased and LDH activity was increased after HGtreatment. Silencing XIST inhibited RTEC pyroptosis by inhibiting NLRP3/caspase-1. Mechanistically,XIST sponged miR-15b-5p to regulate TLR4. Silencing XIST inhibited TLR4 by promotingmiR-15b-5p. miR-15b-5p inhibition or TLR4 overexpression averted the inhibitory effect ofsilencing XIST on HG-induced RTEC pyroptosis.CONCLUSIONSilencing XIST inhibits TLR4 by upregulating miR-15b-5p and ultimately inhibits renal injury inDN by inhibiting NLRP3/caspase-1-mediated RTEC pyroptosis.

Toll-like receptor 3(TLR3)regulation mechanisms and roles in antiviral innate immune responses

Toll-like receptor 3(TLR3)is a member of the TLR family,mediating the transcriptional induction of type I interferons(IFNs),proinflammatory cytokines,and chemokines,thereby collectively establishing an antiviral host response.Studies have shown that unlike other TLR family members,TLR3 is the only RNA sensor that is utterly dependent on the Tollinterleukin-1 receptor(TIR)-domain-containing adaptor-inducing IFN-β(TRIF).However,the details of how the TLR3-TRIF signaling pathway works in an antiviral response and how it is regulated are unclear.In this review,we focus on recent advances in understanding the antiviral mechanism of the TRIF pathway and describe the essential characteristics of TLR3 and its antiviral effects.Advancing our understanding of TLR3 may contribute to disease diagnosis and could foster the development of novel treatments for viral diseases.

中华鳖MyD88部分序列克隆及其在组织中的表达差异分析

MyD88(Myeloid differentiation factor 88,MyD88)是多数TLRs(Toll like receptor,TLRs)信号转导过程中的关键接头分子。研究根据MyD88(Myeloid differentiation factor 88,MyD88)TIR结构域(Toll-like/IL-1 receptor domain)保守区设计简并引物,通过PCR扩增,成功地从中华鳖脾脏cDNA中扩增出351bp的目标序列。测序后经结构域和序列比较分析,扩增片段为中华鳖的MyD88 TIR结构域。该序列与大黄鱼、鸡等脊椎动物的MyD88的TIR结构域序列同源性和相似性分别为72.9%～86%和77.6%～83.6%。以热灭活嗜水气单胞菌刺激中华鳖后,经荧光定量PCR检测,在48h内,肝、脾和肾组织中MyD88 mRNA相对表达量均出现不同程度的增加,尤以脾脏中的增幅最为明显,为对照组的6.89倍;中华鳖心脏成纤维样细胞经20ng LPS刺激后1～8h,MyD88表达量有所提高,24h的表达量最高。该研究结果将为开展中华鳖天然免疫奠定良好基础。

坎地沙坦抑制内毒素诱导的VSMCs炎症因子释放的作用研究

目的：研究坎地沙坦对内毒素（LPS）诱导血管平滑肌细胞（VSMCs）炎症因子释放的影响，探讨 Toll 样受体4（TLR4）介导的信号通路在这一过程中的作用。方法原代培养大鼠 VSMCs ，四甲基偶氮唑蓝（M TT ）法测定不同浓度坎地沙坦对 VSMCs 活性的影响。将细胞分为5组：A 组（对照组）、B 组（LPS 干预组）、C 组（LPS ＋10－7 mol／L 坎地沙坦）、D 组（LPS ＋10－6 mol／L 坎地沙坦）和 E 组（LPS ＋10－5 mol／L 坎地沙坦）。实时定量 PCR 和 Western blot 测定各组细胞 TLR4、髓样分化因子88（Myd88） mRNA 和蛋白的表达、NF‐κB（p65）的核转位水平；ELISA 测定各组细胞上清液白细胞介素‐1β（IL‐1β）和肿瘤坏死因子‐α（TNF‐α）分泌水平；DCFH‐DA 氧化法测定细胞内活性氧（iROS）含量。使用 TLR4阻滞剂 TLR4抗体、NADPH 氧化酶阻滞剂二联苯基碘（DPI）、NF‐κB 阻滞剂 PDTC 或坎地沙坦与阻滞剂联用预处理细胞，ELISA 法测定 IL‐1β和 TNF‐α分泌水平。结果坎地沙坦在10－8～10－3 mol／L 浓度范围内对 VSMCs 活性没有显著影响。同对照组相比，坎地沙坦可以有效抑制 LPS 诱导VSMCs IL‐1β和 TNF‐α的释放，减少 TLR4、Myd88 mRNA 和蛋白的表达以及 iROS 的生成，抑制 NF‐κB（p65）的核转位，并具有剂量依赖性。 TLR4抗体、DPI 、PDTC 均能有效地抑制 LPS 诱导的炎症因子释放，坎地沙坦与阻滞剂联用显示出更强的抗炎作用。结论坎地沙坦能够减少 LPS 诱导的 VSMCs 炎症因子 IL‐1β和 TNF‐α的分泌，这一作用可能是通过抑制 TLR4／Myd88‐iROS‐NF‐κB 信号通路而实现的。

柯里拉京对小鼠单纯疱疹病毒性脑炎Toll样受体3-干扰素诱导链接蛋白通路的调控机制研究

目的:通过柯里拉京(Cor)干预单纯疱疹病毒性脑炎(HSE)小鼠模型,阐明柯里拉京对Toll样受体3(TLR3)信号通路的调控机制。方法:通过颅内注射单纯疱疹病毒1型(HSV1)建立单纯疱疹病毒性脑炎小鼠模型,每天定时灌胃1次等体积的柯里拉京或生理盐水,在第5天断头处死小鼠,取出右侧颞叶病变脑组织进行苏木精-伊红(HE)染色,在显微镜下观察小鼠脑组织病理改变,通过定时定量PCR检测TLR3及其下游信号分子TLR结构域的干扰素诱导链接蛋白(TRIF)mRNA的表达情况,Western blot检测TLR3、TRIF蛋白表达情况,ELISA法检测炎性组织细胞内干扰素α(IFN-α)的分泌情况。结果:HSE小鼠模型中TLR3及其下游分子TRIF的mRNA、蛋白表达及IFN-α的分泌均高于正常对照组(P<0.01);柯里拉京干预可有效缓解动物脑组织的病理变化,且TLR3及其下游分子TRIF的mRNA、蛋白表达及IFN-α的分泌均低于正常对照组(P<0.01)。结论:柯里拉京能明显抑制小鼠小胶质细胞内TLR3通路达到缓解单纯疱疹病毒1型引起的脑组织的损伤。

The IL-1R/TLR signaling pathway is essential for efficient CD8+ T-cell responses against hepatitis B virus in the hydrodynamic injection mouse model

The outcome of hepatitis B viral(HBV)infection is determined by the complex interactions between replicating HBV and the immune system.While the role of the adaptive immune system in the resolution of HBV infection has been studied extensively,the contribution of innate immune mechanisms remains to be defined.Here we examined the role of the interleukin-1 receptor/Toll-like receptor(IL-1R/TLR)signaling pathway in adaptive immune responses and viral clearance by exploring the HBV mouse model.Hydrodynamic injection with a replication-competent HBV genome was performed in wild-type mice(WT)and a panel of mouse strains lacking specific innate immunity component expression.We found higher levels of HBV protein production and replication in Tlr2^(−/−),Tlr23479^(−/−),3d/Tlr24^(−/−),Myd88/Trif^(−/−)and Irak4^(−/−)mice,which was associated with reduced HBV-specific CD8+T-cell responses in these mice.Importantly,HBV clearance was delayed for more than 2 weeks in 3d/Tlr24^(−/−),Myd88/Trif^(−/−)and Irak4^(−/−)mice compared to WT mice.HBV-specific CD8+T-cell responses were functionally impaired for producing the cytokines IFN-γ,TNF-αand IL-2 in TLR signaling-deficient mice compared to WT mice.In conclusion,the IL-1R/TLR signaling pathway might contribute to controlling HBV infection by augmenting HBV-specific CD8+T-cell responses.

The Structure and Sequence Analysis of TLR4 Gene in Cattle

Toll-like receptor 4 （TLR4） is essential for initiating the innate response to lipopolysaccharide （LPS） from Gram-negative bacteria by acting as a signal transducting receptor. In order to help in investigating TLR4 as a candidate disease-resistance gene in cows, we isolated the cDNA （GenBank accession no. DQ839566） by RT-PCR and rapid amplification of cDNA ends （RACE） experiments and analyzed the sequence characters by bioinformatics. The results showed that cattle TLR4 gene about 3 739 bp contains an open reading frame of 2 526 bp encoded 841 amino acids （aa）, 470 bp 5′ untranslated region （UTR）, and 743 bp 3′ UTR. Tissue expression profile by RT-PCR indicated that TLR4 gene expresses in mammary glands, liver, muscle, duodenum, fats, uterus, kidneys, hearts, lungs, pancreas, and ovary. TLR4 protein domain predicted by bioinformatics consists of signal peptide, transmembrane helices domain, 3 sorts of leucine-rich repeat domains （LRR, LRR-TYP, and LRRCT）, and a toll-interleukinl-resistance domain （TIR）. Leucine-rich repeat domains were related with recognizing a broad of pathogen-associated molecular patterns （PAMP） from pathogen, and TIR domain for downstream signaling transduction was most conservative （98% identify） than other domains after alignment of protein from ovine, porcine, human, and mouse. In addition, a 470 bp 5′-flanking region sequence was amplified by PCR, and 15 putative DNA binding sites were predicted, but this sequence lacks TATA box, CCAAT character, and GC-rich regions.

The role of neuroinfammation in glaucoma

Glaucoma is a chronic neurodegener-ative disorder characterized by progressive damage and loss of retinal ganglion cells （RGCs）. It is considered one of the leading causes of irreversible blindness in the older population. There are estimates that glaucoma will affect 80 million individuals worldwide by the end of this de-cade, and yet we are still not able to identify the signals and the mechanisms that trigger this neurodegenerative disease. Various hypotheses have been generated to ad-dress the causes of the progressive RGC death that char-acterizes the disease. Age and increased intraocular pres-sure （IOP） have been established as the main risk factors for the development of glaucoma. Recent studies have identifed additional factors that play a role in the patho-genesis of this complex multifactorial disease, including infammation, oxidative stress, vascular dysregulation, disrupted axonal transport of neurotrophic factors, and the release of neurotoxic agents such as glutamate, nitric oxide and free radicals. The currently approved therapies for glaucoma that seek to reduce IOP, including medica-tions, laser treatment, and surgery, are unable to reliably stop RGC loss and functional impairment. Considering the signifcant personal, medical and socio-economic im-pacts of glaucoma as a leading cause of blindness, there is a pressing need for new innovative treatment strategies. Here we focus on the role of neuroinfammation in glau-coma and the opportunities that new fndings in this area have for the development of future therapeutics.

中华鳖TLR2部分序列的克隆及其组织表达差异分析

为探究中华鳖天然免疫的分子机制,针对TLR2(Toll-like receptor 2)保守区设计兼并引物,从中华鳖脾cDNA中扩增出了740bp的目标序列。测序和序列分析结果表明,该序列包含富含半胱氨酸型C端结构域、跨膜结构域和TIR结构域;与斑马鱼、鸡等脊椎动物相应的TLR2序列相似性为60.5%～74.4%。采用荧光定量PCR检测中华鳖感染嗜水气单胞菌后各组织TLR2mRNA表达的变化,结果显示,感染后第24小时,中华鳖脾和外周血TLR2mRNA相对表达水平升高,其中外周血中的增幅最显著,是对照组的8.57倍;中华鳖外周血经4μg/mL酵母聚糖刺激后,第2小时TLR2mRNA相对表达水平较高。首次获得了中华鳖TLR2部分cDNA序列,并分析了不同刺激物对中华鳖TLR2mRNA转录的影响。

Neuron:新研究为从根源上治疗神经退行性疾病提供线索

对于许多神经退行性疾病来说。比如帕金森病、肌萎缩侧索硬化和外周神经病变，轴突的损失是一个早期的缺陷。当轴突出现损失。神经细胞就无法正常交流，神经系统功能受到损伤。特别是对外周神经病变来说，受损的轴突会触发自毁程序。在一项新研究中。华盛顿大学医学院的科学家们在自毁的轴突中发现一个特殊分子。深入了解损伤如何发生有助于帮助找到阻止其发生的方法。相关研究结果发表在国际学术期刊Neuron上。