ArgD of Mycobacterium tuberculosis is a functional N-acetylornithine aminotransferase with moonlighting function as an effective immune modulator

Mycobacterium tuberculosis (M. tuberculosis) encodes an essential enzyme acetyl ornithine aminotransferase ArgD (Rv1655) of arginine biosynthetic pathway which plays crucial role in M. tuberculosis growth and survival. ArgD catalyzes the reversible conversion of N-acetylornithine and 2 oxoglutarate into glutamate-5-semialdehyde and L-glutamate. It also possesses succinyl diaminopimelate aminotransferase activity and can thus carry out the corresponding step in lysine biosynthesis. These essential roles played by ArgD in amino acid biosynthetic pathways highlight it as an important metabolic chokepoint thus an important drug target. We showed that M. tuberculosis ArgD rescues the growth of ΔargD E. coli grown in minimal media validating its functional importance. Phylogenetic analysis of M. tuberculosis ArgD showed homology with proteins in gram positive bacteria, pathogenic and non-pathogenic mycobacteria suggesting the essentiality of this protein. ArgD is a secretory protein that could be utilized by M. tuberculosis to modulate host innate immunity as its moonlighting function. In-silico analysis predicted it to be a highly antigenic protein. The recombinant ArgD protein when exposed to macrophage cells induced enhanced production of pro-inflammatory cytokines TNF, IL6 and IL12 in a dose dependent manner. ArgD also induced the increased production of innate immune effector molecule NOS2 and NO in macrophages. We also demonstrated ArgD mediated activation of the canonical NFkB pathway. Notably, we also show that ArgD is a specific TLR4 agonist involved in the activation of pro-inflammatory signaling for sustained production of effector cytokines. Intriguingly, ArgD protein treatment activated macrophages to acquire the M1 phenotype through the increased surface expression of MHCII and costimulatory molecules CD80 and CD86. ArgD induced robust B-cell response in immunized mice, validating its antigenicity potential as predicted by the in-silico analysis. These properties of M. tuberculosis ArgD signify its functional plasticity that could be exploited as a possible drug target to combat tuberculosis.     

外周血单个核细胞内人类免疫缺陷病毒DNA和RNA定量对病毒转录活性的区分

目的基于人类免疫缺陷病毒Ⅰ型(HIV-1)感染者外周血单个核细胞(PBMCs)中HIV-1总DNA和RNA定量检测结果对感染细胞内病毒的转录活性进行区分。方法采集2017年10月至2018年12月于哈尔滨医科大学附属第四医院感染科就诊的HIV-1感染者血液样本,分离PBMCs细胞,采用PCR荧光探针法对PBMCs细胞内HIV-1总DNA和RNA进行定量检测,并计算两者比值(Ratio)。根据Ratio值筛选出HIV-1转录活跃组样本和相对非活跃组样本,另外选择健康人PBMCs样本作为对照组。对3组样本进行基因转录组表达谱检测以及人口特征差异性检验,并对基因表达谱检测结果进行主成分分析以验证对3组样本病毒转录活性区分的准确性。结果从60例感染HIV-1患者的PBMCs样本中筛选出HIV-1转录活跃组样本(10例)和相对非活跃组样本(11例),另外选择6例健康人PBMCs样本作为对照组。其中转录活跃组样本Ratio值为165.2~738.93,平均为(339.27±189.68);相对非活跃组Ratio值为4.67~42.39,平均为(17.65±11.78)。转录活跃组和相对非活跃组样本间的CD4+T细胞计数(P=0.049)和Ratio值(P<0.001)差异均具有统计学意义;3组样本年龄(P=0.989)和性别(P=0.650)分布差异无统计学意义。对3组样本的PBMCs基因表达谱主成分分析结果显示:对照组与HIV-1感染者(包括转录活跃组和相对非活跃组)间区分明显。转录活跃组和相对非活跃组间有部分样本重合,同时结果也显示当HIV-1感染者的CD4+T淋巴细胞计数与健康人无显著差异时,其细胞内的基因表达与健康人接近。结论基于HIV-1总DNA和RNA定量检测结果及两者间比值可以较好地区分PBMCs内病毒转录活性。HIV-1感染细胞内部病毒的不同转录激活状况可导致其基因表达谱的异质性。     

The potential role of assisted oocyte activation in the management of a POSEIDON group 3 patient with fertilization failure: A case report and literature review

ObjectiveAssisted oocyte activation combined with ICSI (ICSI-AOA) has been reported to improve fertilization outcomes of couples with oocyte activation deficiency (OAD). Although there's no sufficient evidence to support ICSI-AOA as routine use, it might be beneficial for POSEIDON group 3 patients with suspected oocyte-related OAD.Case reportA 29-year-old female presented with a history of primary infertility for two years. She was classified as a POSEIDON group 3 patient and had a total fertilization failure history. With the help of ICSI-AOA, six oocytes were successfully fertilized. Pregnancy was later confirmed after embryo transfer. A living infant was born after 34 weeks of pregnancy.ConclusionOAD should be taken into consideration for POSEIDON group 3 patients since low Antimüllerian hormone is associated decreased quality. Further research needs to be done to understand the mechanism underlying oocyte-related OAD and the potential role of ICSI-AOA in young patients with suboptimal ovarian response.     

Cutaneous histiocytoses in children

Cutaneous histiocytoses constitute a heterogeneous group of diseases characterised by the cutaneous accumulation of cells with the cytological and phenotypic features of macrophages or dendritic cells. The clinical spectrum ranges from self-resolving, skin-limited conditions to severe, multiorgan disease with a high morbidity rate. Until recently, cutaneous histiocytoses were classified according to the immunophenotype of the pathological cells, with differentiation between Langerhans cell histiocytosis (LCH) [CD1a+, CD207 (langerin)+] and non-Langerhans cell histiocytosis (CD68+, CD163+, CD1a?, CD207?). Over the last 12 years, a number of new pathophysiological findings (in particular, molecular pathology results) regarding histiocytoses have contributed to a new classification based on molecular alterations, as well as on clinical and imaging characteristics and the phenotype. The most frequent entities in children are juvenile xanthogranuloma and LCH.     

大黄素治疗代谢相关脂肪性肝病的作用机制研究进展

代谢相关脂肪性肝病既往称为非酒精性脂肪肝，与肥胖、糖尿病、高脂血症等关系密切，还明显增加心血管死亡的风险。大黄素是大黄、何首乌中主要的活性成分，具有多种生物学功能。大黄素可通过降低肝细胞脂质沉积、抑制肝脏炎症反应、抗胰岛素抵抗、抑制肝纤维化、抗氧化应激反应等多种途径对代谢相关脂肪性肝病发挥治疗作用。总结了大黄素治疗代谢相关脂肪性肝病的作用机制，为代谢相关脂肪性肝病的治疗提供参考。     

代谢手术治疗肥胖型多囊卵巢综合征的 meta 分析

目的: 系统评价代谢手术对肥胖型多囊卵巢综合征的影响。方法: 检索 PubMed、EMBASE、Cochrane Library、CNKI 和万方数据库。检索时间为 2000－01 ～ 2017－05。结局指标包括 PCOS、月经周期异常、多毛症、不 孕症。结果: 纳入的 19 篇报道中，共纳入接受代谢手术病人共 2716 例，其中女性病人 2274 例。经代谢手术后， PCOS 发生率术前12．27%术后降低为4．76%( 95%CI: 2．14 ～ 9．86，Z = 3．92，P＜0．0001) 。月经周期异常发生率术前 34．43%术后降低为10．79%( 95%CI: 5．62～ 26．15，Z= 6．36，P＜0．0001) 。多毛症发生率70．59%降低为21．01%( 95% CI: 3．57～ 31．06，Z= 4．27，P＜0．0001) 。不孕症发生率7．69%术后降低为2．56% ( 95% CI: 1．77 ～ 5．81，Z = 3．85，P = 0．0001) 。结论: 代谢手术可显著改善肥胖型多囊卵巢综合征的临床症状。     

A DNA vaccine expressing an optimized secreted FAPα induces enhanced anti-tumor activity by altering the tumor microenvironment in a murine model of breast cancer

Cancer-associated fibroblasts (CAFs), major components of the tumor microenvironment (TME), promote tumor growth and metastasis and inhibit the anti-tumor immune response. We previously constructed a DNA vaccine expressing human FAPα, which is highly expressed by CAFs, to target these cells in the TME, and observed limited anti-tumor effects in the 4T1 breast cancer model. When the treatment time was delayed until tumor nodes formed, the anti-tumor effect of the vaccine completely disappeared. In this study, to improve the safety and efficacy, we constructed a new FAPα-targeted vaccine containing only the extracellular domain of human FAPα with a tissue plasminogen activator signal sequence for enhanced antigen secretion and immunogenicity. The number of CAFs was more effectively reduced by CD8⁺ T cells induced by the new vaccine. This resulted in decreases in CCL2 and CXCL12 expression, leading to a significant decrease in the ratio of myeloid-derived suppressor cells in the TME. Moreover, when mice were treated after the establishment of tumors, the vaccine could still delay tumor growth. To facilitate the future application of the vaccine in clinical trials, we further optimized the gene codons and reduced the homology between the vaccine and the original sequence, which may be convenient for evaluating the vaccine distribution in the human body. These results indicated that the new FAPα-targeted vaccine expressing an optimized secreted human FAPα induced enhanced anti-tumor activity by reducing the number of FAPα⁺ CAFs and enhancing the recruitment of effector T cells in the 4T1 tumor model mice.