JQ-1 ameliorates schistosomiasis liver granuloma in mice by suppressing male and female reproductive systems and egg development of Schistosoma japonicum

Schistosomiasis is a serious and widespread parasitic disease caused by infection with Schistosoma. Because the parasite’s eggs are primarily responsible for schistosomiasis dissemination and pathogenesis, inhibiting egg production is a potential approach to control the spread and severity of the disease. The bromodomain and extra-terminal (BET) proteins represent promising targets for the development of epigenetic drugs against Schistosoma. JQ-1 is a selective inhibitor of the BET protein family. In the present study, JQ-1 was applied to S. japonicum in vitro. By using laser confocal scanning microscopy and EdU incorporation assays, we showed that application of JQ-1 to worms in vitro affected egg laying and the development of both the male and female reproductive systems. JQ-1 also inhibited the expression of the reproductive-related genes SjPlk1 and SjNanos1 in S. japonicum. Mice infected with S. japonicum were treated with JQ-1 during egg granuloma formation. JQ-1 treatment significantly reduced the size of the liver granulomas and levels of serum alanine aminotransferase and aspartate aminotransferase in mice and suppressed both egg laying and the development of male and female S. japonicum reproductive systems in vivo. Moreover, the mRNA expression levels of some proinflammatory cytokines were decreased in the parasites. Our findings suggest that JQ-1 treatment attenuates S. japonicum egg–induced hepatic granuloma due at least in part to suppressing the development of the reproductive system and egg production of S. japonicum. These findings further suggest that JQ-1 or other BET inhibitors warrant additional study as a new approach for the treatment or prevention of schistosomiasis.     

Different protective roles in vitro of alpha- and beta-domains of growth inhibitory factor (GIF) on neuron injuries caused by oxygen free radicals.

It was well known that beta-amyloid (Abeta) and tau protein play an important role in pathological procedure of Alzheimer's disease (AD), a senile dementia. The growth inhibitory factor (GIF, also named metallothionein-3, MT-3) had been demonstrated to inhibit the outgrowth of cortex neurons in the medium with extract of the AD patient brain. In our experiments, it was found that the neurons of cortex and the PC12 (pheochromocytoma) cells could be protected from the cytotoxicity of beta-amyloid 25-35 in presence of GIF and its domains. Additionally, GIF can scavenge the hydroxyl radical efficiently in CytC-VitC radical producing system and its alpha-domain shown more effective potentials than its beta-domain. The electron paramagnetic resonance spectra also show that the alpha-domain has more potential ability for eliminating reactive oxygen free radicals than its beta-domain. The results suggest that GIF could act as an efficient scavenger against free radicals in vitro and the alpha-domain in GIF molecule shows more potential in protecting against reactive oxygen species injury than the beta-domain.     

Organization and possible origin of the Bari-1 cluster in the heterochromatic h39 region of Drosophila melanogaster

The molecular organization of the heterochromatic h39 region of the Drosophila melanogaster second chromosome has been investigated by studying two BAC clones identified both by Southern blotting and by FISH experiments as containing tandem arrays of Bari1, a transposable element present only in this region. Such BAC clones appear to contain different portions of the h39 region since they differ in the DNA sequences flanking the Bari1 repeats on both sides. Thus, the 80 Bari1 copies estimated to be present in the h39 region are split into at least two separated subregions. On the basis of the analysis of the flanking sequences a possible mechanism depending on an aberrant activity of the Bari1 transposase is proposed for the genesis of the heterochromatic tandem arrays of the element.     

Engineering mouse apolipoprotein A-I into a monomeric, active protein useful for structural determination

Apolipoprotein AI (apoAI), the major protein component of HDL, is one of the best predictors of coronary artery disease (CAD), with high apoAI and HDL levels being correlated with low occurrences of CAD. The primary function of apoAI is to recruit phospholipid and cholesterol for assembly of HDL particles. Like other exchangeable apolipoproteins, lipid-free apoAI forms a mixture of different oligomers even at 1.0 mg/mL. This self-association property of the exchangeable apolipoproteins is closely associated with the lipoprotein-binding activity of this protein family. It is unclear if the self-association property of apolipoprotein is required for its lipoprotein-binding activity. We developed a novel method for engineering an oligomeric protein to a monomeric, biologically active protein. Using this method, we generated a monomeric mouse apoAI mutant that is active. This mutant contains the first 216 residues of mouse apoAI and replaces six hydrophobic residues with either polar or smaller hydrophobic residues at the defined positions (V118A/A119S/L121Q/T191S/T195S/T199S). Cross-linking results show that this mutant is greater than 90% monomeric at 8 mg/mL. CD, DSC, and NMR results indicate that the mutant maintains an identical secondary, tertiary structure and stability as those of the wild-type mouse apoAI. Lipid-binding assays suggest that the mutant shares an equal lipoprotein-binding activity as that of the wild-type apoAI. In addition, both the monomeric mutant and the wild-type protein make nearly identical rHDL particles. With this monomeric mouse apoAI, high-quality NMR data has been collected, allowing for the NMR structural determination of lipid-free apoAI. On the basis of these results, we conclude that this apoAI mutant is a monomeric, active apoAI useful for structural determination.     

Wnt/β-catenin信号通路在博来霉素诱导的系统性硬化症小鼠模型血管重塑中的作用

系统性硬化症(systemic sclerosis,SSc)是一种慢性可累及全身多脏器的自身免疫性疾病,以广泛的血管病变及皮肤和内脏的纤维化为特征,但其机制迄今尚不明确。已有研究证实,Wnt通路参与了SSc纤维化,但其在血管病变中的病理作用尚未见报道。本研究拟采用博来霉素(bleomycin,BLM)诱导的SSc小鼠模型,探讨Wnt通路在SSc皮肤血管病变中的作用。将18只Balb/C小鼠随机平均分为3组,分别设为对照组(于小鼠背部皮下注射PBS 100 μL/d)、模型组(于小鼠背部皮下注射浓度为 1 mg/mL 博来霉素BLM 100 μL/d)和治疗组(于小鼠背部皮下注射 1 mg/mL BLM 100 μL/d,同时腹腔注射Wnt及β-catenin的抑制剂 iCRT3 5 mg/kg·d),于造模第28 d处死小鼠。小鼠皮肤取材后,通过HE染色及Masson染色观察到经BLM诱导的模型组小鼠背真皮、表皮厚度较对照组皮肤均明显增加(P<0.05),同时模型组的皮脂腺、毛囊等皮肤附属器明显减少,脂肪层厚度变薄并被纤维组织包绕,模型组皮肤胶原沉积较对照组增加;通过免疫组织化学染色在组织学层面鉴定α-SMA表达情况,发现模型组及治疗组α-SMA在皮肤组织中均高表达,α-SMA阳性表达在血管周围较对照组明显增加;通过ELISA方法检测出模型组小鼠血清中IL-6及IL-17表达量较对照组明显升高(P<0.05),治疗组小鼠血清中IL-6及IL-17的表达量较模型组明显下降(P<0.05);提取皮肤微血管片段,通过q-PCR检测到模型组及治疗组小鼠皮肤微血管中β-联蛋白的mRNA基因表达水平较正常组升高;通过Western印迹检测皮肤微血管Wnt5A、β-联蛋白、α-SMA、col1A1的蛋白质表达情况,发现纤维化相关蛋白质α-SMA及col1A1在模型组表达升高,较对照组有统计学差异(P<0.05),治疗组较模型组表达下降(P<0.05),Wnt通路相关蛋白质β-联蛋白及Wnt5A在模型组表达明显升高,较之对照组有统计学差异(P<0.05)。本研究提示,BLM能成功诱导小鼠系统性硬化症皮肤表型,Wnt通路的异常激活参与了BLM诱导的硬皮病小鼠皮肤微血管病变,特异性Wnt通路抑制剂iCRT3可能通过直接或间接的方式下调细胞因子IL-6及IL-17,从而降低BLM诱导的小鼠皮肤微血管中的α-SMA及col1A1蛋白质表达,改善小鼠皮肤微血管病变,干预BLM诱导的小鼠血管病变的进展。