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目的探讨骨髓间充质干细胞（MSCs）治疗急性腹膜纤维化的作用方式。方法取SD大鼠114只,制作急性膜腹粘连模型,其中6只在腹膜刮伤后24h经尾静脉（n=3）或腹腔（n=3）注入MSCs,采用活体成像示踪法观察MSCs的分布并对两种方式注射后MSCs的示踪效果进行比较;其余108只大鼠随机分为无血清条件培养基（CM）治疗组、MSCs治疗组和对照组（每组36只）,取CM、MSCs（5×106）或PBS各1ml于腹膜刮伤24h经尾静脉注射,然后对各组进行粘连评分、Masson染色、免疫荧光法观察腹膜炎症、纤维化及间皮细胞修复情况。结果活体成像示踪可见,MSCs经尾静脉注入后主要在肺脏积聚,经腹腔注入后主要在肝脏积聚,而损伤腹膜区均未见积聚。与对照组相比,CM与MSCs治疗可同等程度地改善腹膜粘连的肉眼评分（P〈0.05）。病理Masson染色显示,与对照组相比,CM与MSCs治疗可同等程度地减轻腹膜损伤后2d的炎症细胞浸润,减少4、6和14d胶原纤维数量。免疫荧光分析发现,CM可增加腹膜损伤后2、4和6d的间皮细胞数量,并减少4、6和14d的成纤维细胞数量及转化生长因子β1的（TGF-β1）表达水平。结论 MSCs减轻急性腹膜纤维化的作用并非通过细胞定植实现的,而可能是与分泌可溶性细胞因子有关。CM可促进间皮修复、抑制炎症从而减轻腹膜纤维化。

Aim： Microvesicles （MVs） are nanoscale membrane fragments released from virtually all cell types upon activation or apoptosis, and may contribute to the beneficial effects of stem cell therapy. In this study, we investigated the therapeutic effects of mesenchymal stem cell （MSC） derived MVs （MSC-MVs） on pulmonary artery hypertension （PAH） in rats. Methods： MSC-MVs were isolated from rat bone marrow MSCs that were cultured in a serum-free conditioned medium. Transmission electron microscopy （TEM）, flow cytometry and nanoparticle tracking analysis （NTA） were used to characterize the MVs. Adult SD rats were injected with monocrotaline （50 mg/kg, sc） to induce PAH. Three weeks later, the rats were intravenously injected with MSCs, MSC-MVs or saline for 2 weeks. At the end of treatments, the hemodynamic parameters and pathological right ventricular and pulmonary arterial remodeling were analyzed in each group. Results： The MSC-MVs showed general morphologic characteristics of MVs and expressed annexin V and CD29 markers under TEM, and their size ranged from 40 to 300 nm. Intravenous injection of MSC-MVs or MSCs significantly ameliorated the mean pulmonary artery pressure （mPAP） and mean right ventricle pressure （mRVP） in PAH rats. Furthermore, intravenous injection of MSC-MVs or MSCs significantly decreased the right ventricle （RV） hypertrophy and pulmonary arteriole area index （AI） and thickness index （TI） in PAH rats. Conclusion： Intravenous injection of MSC-MVs or MSCs produces similar beneficial effects for treating PAH, and our results provide a basis for cell-free approach in stem cell therapy.

Bone metastasis is a frequent complication of breast cancer and a common cause of morbidity and mortality from the disease. During metastasis secreted proteins play crucial roles in the interactions between cancer cells and host stroma. To characterize the secreted proteins that are associated with breast cancer bone metastasis, we preformed a label-free proteomic analysis to compare the secretomes of four MDA-MB-231 （MDA231） derivative cell lines with varied capacities of bone metastasis. A total of 128 proteins were found to be consistently up-/down-regulated in the conditioned medium of bone-tropic cancer cells. The enriched molecular functions of the altered proteins included receptor binding and peptidase inhibition. Through additional transcriptomic analyses of breast cancer cells, we selected cystatin E/M （CST6）, a cysteine protease inhibitor down-regulated in bone-metastatic cells, for further functional studies. Our results showed that CST6 suppressed the proliferation, colony formation, migration and invasion of breast cancer cells. The suppressive function against cancer cell motility was carried out by cancer cell-derived soluble CST6. More importantly, ectopic expression of CST6 in cancer cells rescued mice from overt osteolytic metastasis and deaths in the animal study, while CST6 knockdown markedly enhanced cancer cell bone metastasis and shortened animal survival. Overall, our study provided a systemic secretome analysis of breast cancer bone tropism and established secreted CST6 as a bonafide suppressor of breast cancer osteolytic metastasis.

D-alanine （D-Ala） is an essential amino acid that has a key role in bacterial unique enzyme that interconverts L-alanine and D-alanine in most bacteria, antimicrobial drug development. Streptococcus mutans is a major causative cell wall synthesis. Alanine racemase （Air） is a making this enzyme a potential target for factor of dental caries. The factors involved in the survival, virulence and interspecies interactions of S. mutans could be exploited as potential targets for caries control. The current study aimed to investigate the physiological role of Air in S. mutans. We constructed air mutant strain of S. mutans and evaluated its phenotypic traits and interspecies competitiveness compared with the wild-type strain. We found that air deletion was lethal to S. mutans. A minimal supplement of D-Ala （150 pg.mL- 1） was required for the optimal growth of the air mutant. The depletion of D-alanine in the growth medium resulted in cell wall perforation and cell lysis in the air mutant strain. We also determined the compromised competitiveness of the air mutant strain relative to the wild-type S. mutans against other oral streptococci （S. sanguinis or S. gordonil~, demonstrated using either conditioned medium assays or dual-species fluorescent in situ hybridization analysis. Given the importance and necessity of air to the growth and competitiveness of S. mutans, Air may represent a promising target to modulate the cariogenicity of oral biofilms and to benefit the management of dental caries.

Osteoarthritis is recognised to be an interactive pathological process involving the cartilage, subchondral bone and synovium. The signals from the synovium play an important role in cartilage metabolism, but little is known regarding the influence of the signalling from bone. Additionally, the collagenases and stromelysin-1 are involved in cartilage catabolism through mitogen-activated protein kinase （MAPK） signalling, but the role of the gelatinases has not been elucidated. Here, we studied the influence of osteoclastic signals on chondrocytes by characterising the expression of interleukin-1β （IL-1β）-induced gelatinases through MAPK signalling. We found that osteoclast-conditioned media attenuated the gelatinase activity in chondrocytes. However, IL-1β induced increased levels of gelatinase activity in the conditioned media group relative to the mono-cultured chondrocyte group. More specifically, IL-1β restored high levels of gelatinase activity in c-Jun N-terminal kinase inhibitor-pretreated chondrocytes in the conditioned media group and led to lower levels of gelatinase activity in extracellular signal-regulated kinase or p38 inhibitor-pretreated chondrocytes. Gene expression generally correlated with protein expression. Taken together, these results show for the first time that signals from osteoclasts can influence gelatinase activity in chondrocytes. Furthermore, these data show that IL-11~ restores gelatinase activity through MAPK inhibitors; this information can help to increase the understanding of the gelatinase modulation in articular cartilage.

光皮桦为我国南方桦木科优良乡土速生树种，适应性强，用途广。实生苗造林6年生平均树高可达8．8m，胸径可达9．2cm，早期速生，适合培育大中径材。现南方正大力推广种植，经济效益极佳，但良种选育为亟待解决的问题。组培快繁技术是解决优良无性系造林的良好途径，为此，热带林业实验中心组培室的科技人员经过近2年的探索，已成功解决光皮桦组培快繁的技术难题，现报道如下：