低温海水浸泡对大鼠血浆蛋白质组的影响研究

目的模拟海难落水所致重度低体温损伤,比较鉴定低温海水浸泡模型动物血浆蛋白质组差异,为研究低体温相关血浆蛋白提供线索。方法将50只雄性健康Wistar大鼠平均分成5组,分别在低温海水中浸泡0、2、4、6、10 h后采集下腔静脉血。分离血浆后,用试剂盒去除Ig G和白蛋白等高丰度蛋白,并经过除盐后采用蛋白质双向凝胶电泳(2-DE)分离。对差异1.5倍以上的蛋白斑点,用基质辅助激光解析电离飞行时间质谱(MALDI-TOF-MS)进行肽质量指纹图谱分析,应用NCBI或Swiss-prot数据库鉴定差异蛋白质。结果大鼠浸泡在15℃海水中,中心体温(肛温)迅速下降,浸泡30 min降至19℃,浸泡120 min降至16℃左右,体温维持不变,说明进入重度低体温状态。初步鉴定出3个与低温相关差异蛋白,肺表面相关蛋白A(SP-A)、丝氨酸蛋白酶抑制剂A3K(SPA3K)和抑制物组织基质金属蛋白酶抑制剂-3(TIMP-3)。与正常大鼠相比,这3个蛋白的表达水平均随着低温海水浸泡时间的延长明显上调。结论低温海水浸泡后的大鼠血浆蛋白质组相对正常大鼠血浆蛋白质组有改变。研究差异蛋白有助于阐明低温损伤的分子机制,为研究和治疗低体温症提供靶标。     

Prognostic significance of resident CD103+CD8+T cells in human colorectal cancer tissues

The prognostic significance and clinical implications of resident CD103⁺CD8⁺T cells in human colorectal cancer tissues still remains largely unexplored. In our present study, we aimed to characterize the resident CD8⁺T cells in human colorectal cancer tissues by using double staining of CD103 and CD8, and further evaluated the prognostic significance of resident CD8⁺T cells in colorectal cancer. We found that the OS rate of the colorectal cancer patients with higher infiltration of CD8⁺T cells, or with higher numbers of resident CD103⁺CD8⁺T cells, or with higher ratio of CD103⁺CD8⁺T cells over total CD8⁺T cells in cancer tissues was significantly better than that of the patients with lower infiltration of CD8⁺T cells, or with lower numbers of resident CD103⁺CD8⁺T cells, or with higher ratio of CD103⁺CD8⁺T cells over total CD8⁺T cells in cancer tissues, respectively. Moreover, higher infiltration of CD8⁺T cells in colorectal cancer tissues was significantly and inversely correlated with advanced TNM stage. Higher numbers of resident CD103⁺CD8⁺T cells in colorectal cancer tissues were significantly and inversely correlated with distant metastasis status. Higher ratio of CD103⁺CD8⁺T cells over total CD8⁺T cells in colorectal cancer tissues was significantly and inversely correlated with age status. The COX model analysis demonstrated that higher infiltration of CD8⁺T cells, higher numbers of resident CD103⁺CD8⁺T cells, or higher ratio of CD103⁺CD8⁺T cells over total CD8⁺T cells in colorectal cancer tissues, could serve as independent prognostic predictors for colorectal cancer patients. Taken together, our present study demonstrated the density of tumor infiltrating CD8⁺T cells or the numbers of resident CD103⁺CD8⁺T cells in colorectal tissues could be used as an important prognostic predictor for this malignancy.     

The clinical significance of plasma CFHR 1–5 in lupus nephropathy

A deficiency of complement factor H may lead to excessive consumption of C3 and an increase in C3b deposition, which are important pathological characteristics of lupus nephritis. Complement factor H-related proteins (CFHRs), comprising CFHR1 to CFHR5 (CFHR1–5), are members of the wider factor H/CFHR family. Their role in lupus nephritis remains unclear. In this study, we compared circulating levels of CFHR1–5 in 152 patients diagnosed with lupus nephritis and 20 unrelated healthy individuals to explore the relationship between the expression of CFHR1–5 and development of the disease. We found that plasma levels of CFHR3 and CFHR5 were higher in patients with lupus nephritis than in healthy individuals; also, CFHR3 and CFHR5 concentrations increased with increasing systemic lupus erythematosus disease activity index (SLEDAI) values (P < 0.05). Pearson's and Spearman's correlation test results confirmed that plasma CFHR3 and CFHR5 levels in lupus nephritis patients were positively correlated with proteinuria and levels of creatinine (Cr) and anti-dsDNA (correlation coefficients = 0.491–0.717, P < 0.05), while they were negatively correlated with plasma C3 levels and eGFR [correlation coefficients = –(0.706–0.788), P < 0.05]. Receiver operating characteristic (ROC) curve analysis results confirmed that plasma CFHR3 and CFHR5 levels were predictive of SLEDAI values and disease end points (area under the curve = 0.664–0.884, P < 0.05), with patients with both high CFHR3 and high CFHR5 exhibiting the shortest progression-free survival. Thus, both CFHR3 and CFHR5 are of prognostic value in lupus nephritis status.     

High genetic diversity and recombination events of porcine astrovirus strains identified from ill and asymptomatic pigs in 2017, Hunan Province,China

Astroviruses (AstV) are associated with enteric and systemic disease in mammals and birds. Astroviruses have received increased attention recently as they have been found to be associated with sporadic neurologic disease in mammals including humans. In pigs, porcine astrovirus (PoAstV) can be widely detected and has been grouped in five genotypes (PoAstV1 to PoAstV5). In the present study, we detected multiple PoAstVs in serum samples, nasal swabs, and fecal swabs collected from pigs suffering from respiratory disease or diarrhea but also from asymptomatic pigs, indicating a wide tissue tropism of the identified PoAstV genotypes. Coinfection of different genotypes in the same pig was commonly observed, and within an individual pig a high genetic diversity was observed for viruses belonging to the same PoAstV genotype. Two complete genomes of PoAstV2-WG-R2/2017 and PoAstV4-WG-R2/2017 were successfully obtained and characterized, with genome sizes of 6396 and 6643 nucleotides, respectively. The PoAstV2-WG-R2/2017 genome showed identities of 67.2–77.4% to other known PoAstV2 genomes, and the PoAstV4-WG-R2/2017 genome showed identities of 72.8–80.5% to other known PoAstV4 genomes. The predicted spike domain of open reading frame 2 (ORF2) of these strains showed the highest genetic heterogeneity, with amino acid identities of 13.7–70.9% for PoAstV2-WG-R2/2017 to other known PoAstV2 strains, and identities of 24.4–63.3% for the PoAstV4-WG-R2/2017 to other known PoAstV4 strains. Possible recombination events were identified in each of the two sequences. Two subclades of PoAstV2 and three subclades of PoAstV4 were defined in the present analyses. The obtained data provide further evidence for extraintestinal infectivity of PoAstVs, and confirmed the high genetic diversity of PoAstVs and the coinfection potential of different PoAstV types in a single pig.

     

Infection patterns,clinical significance,and genetic characteristics of Enterocytozoon bieneusi and Giardia duodenalis in dairy cattle in Jiangsu,China

The infection patterns and clinical significance of Enterocytozoon bieneusi and Giardia duodenalis in dairy cattle remain poorly investigated despite their common occurrence. Data on the genetic diversity are also needed to understand the transmission and human-infective potential of the two pathogens. In this study, fecal specimens from 1366 dairy cattle on a large farm were examined for the presence and genotype distribution of E. bieneusi and G. duodenalis by PCR and DNA sequencing. The overall infection rates of E. bieneusi and G. duodenalis were 13.0% and 20.6%, respectively. Pre-weaned calves had significantly higher infection rates of both pathogens than post-weaned and adult cattle (P < 0.001), with peak occurrence of the pathogens in animals of 7–12 weeks. In both pre- and post-weaned calves, animals with diarrhea were 2.1–3.0 times more likely to be infected with either pathogen than those without diarrhea (P < 0.01). The E. bieneusi identified belonged to five genotypes, including J (n = 138), I (n = 21), BEB4 (n = 10), Type IV (n = 1), and a novel genotype CHC17 (n = 1). Genotype J was the dominant one in all age groups, whereas genotype I was only identified in calves of 6–11 weeks. Genotyping of G. duodenalis at three genetic loci identified assemblage E (n = 278), assemblage A (n = 2), and concurrence of the two (n = 1). Altogether, 13, 7 and 10 subtypes of assemblage E were detected at the bg, gdh, and tpi loci, respectively, forming 65 multilocus genotypes. The formation of two major clusters of MLGs in eBURST analysis indicated that intra-assemblage genetic recombination of two dominant MLGs could have led to the high genetic heterogeneity within assemblage E on a single farm. Results of this study provide much needed data on the pathogenicity of E. bieneusi and G. duodenalis in pre- and post-weaned calves. The clinical significance of the two pathogens in dairy cattle warrants further investigations.

     

重离子放射治疗技术及临床应用

重离子的细胞杀伤作用大,有倒转剂量分布优势,而且具有拓展布拉格峰、高传能线密度、高相对生物效应等特点。将其应用于癌症治疗,可使深部区域肿瘤细胞因高剂量辐射而被有效杀灭,而对周围组织因低剂量分布、相对危害较小,能实现精确靶向治疗,这也被认为是最有前景的肿瘤放疗技术。本文简要介绍了重离子放射治疗的物理和生物学特征,回顾了重离子放射治疗的发展历程及现状;重点阐述了重离子放射治疗技术在临床的应用现状及优势,以期为重离子辐射生物学的研究人员提供一定的数据参考和未来方向参考,更好地促进重离子放射治疗在临床治癌中的良好应用。     

Graphene oxide regulates cox2 in human embryonic kidney 293T cells via epigenetic mechanisms: dynamic chromosomal interactions

To extend the applications of engineered nanomaterials, such as graphene oxide (GO), it is necessary to minimize cytotoxicity. However, the mechanisms underlying this cytotoxicity are unclear. Dynamic chromosomal interactions have been used to illustrate the molecular bases of gene expression, which offers a more sensitive and cutting-edge technology to elucidate complex biological processes associated with epigenetic regulations. In this study, the role of GO-triggered chromatin interactions in the activation of cox2, a hallmark of inflammation, was investigated in normal human cells. Using chromosome conformation capture technology, we showed that GO triggers physical interactions between the downstream enhancer and the cox2 promoter in human embryonic kidney 293T (293T) via p65 and p300 complex-mediated dynamic chromatin looping, which was required for high cox2 expression. Moreover, tumor necrosis factor-α (TNF-α), located upstream of the p65 signaling pathway, contributed to the regulation of cox2 activation through dynamic chromatin architecture. Compared with pristine GO and aminated GO (GO-NH₂), poly (acrylic acid)-functionalized GO (GO-PAA) induced a weaker inflammatory response and a weaker effect on chromatin architecture. Our results mechanistically link GO-mediated chromatin interactions with the regulation of cox2 and suggest that GO derivatives may minimize toxicity in practical applications.