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Epidemiological evidence suggests that bone is especially sensitive to oxidative stress, causing bone loss in the elderly. Previous studies indicated that human amnion-derived mesenchymal stem cells (HAMSCs), obtained from human amniotic membranes, exerted osteoprotective effects in vivo. However, the potential of HAMSCs as seed cells against oxidative stress-mediated dysfunction is unknown. In this study, we systemically investigated their antioxidative and osteogenic effects in vitro. Here, we demonstrated that HAMSCs signi cantly promoted the proliferation and osteoblastic differentiation of H2O2-induced human bone marrow mesenchymal stem cells (HBMSCs), and down-regulated the reactive oxygen species (ROS) level. Further, our results suggest that activation of the ERK1/2 MAPK signal transduction pathway is essential for both HAMSCs-mediated osteogenic and protective effects against oxidative stress-induced dysfunction in HBMSCs. U0126, a highly selective inhibitor of extracellular ERK1/2 MAPK signaling, significantly suppressed the antioxidative and osteogenic effects in HAMSCs. In conclusion, by modulating HBMSCs, HAMSCs show a strong potential in treating oxidative stress- mediated bone deficiency. 相似文献
804.
Yifei Wang Jingbin Zheng Md Sahidul Islam Yang Yang Yuanjia Hu Xin Chen 《International journal of biological sciences》2021,17(6):1507
The severe cases of Coronavirus Disease 2019 (COVID-19) frequently exhibit excessive inflammatory responses, acute respiratory distress syndrome (ARDS), coagulopathy, and organ damage. The most striking immunopathology of advanced COVID-19 is cytokine release syndrome or “cytokine storm” that is attributable to the deficiencies in immune regulatory mechanisms. CD4+FoxP3+ regulatory T cells (Tregs) are central regulators of immune responses and play an indispensable role in the maintenance of immune homeostasis. Tregs are likely involved in the attenuation of antiviral defense at the early stage of infection and ameliorating inflammation-induced organ injury at the late stage of COVID-19. In this article, we review and summarize the current understanding of the change of Tregs in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and discuss the potential role of Tregs in the immunopathology of COVID-19. The emerging concept of Treg-targeted therapies, including both adoptive Treg transfer and low dose of IL-2 treatment, is introduced. Furthermore, the potential Treg-boosting effect of therapeutic agents used in the treatment of COVID-19, including dexamethasone, vitamin D, tocilizumab and sarilumab, chloroquine, hydroxychloroquine, azithromycin, adalimumab and tetrandrine, is discussed. The problems in the current study of Treg cells in COVID-19 and future perspectives are also addressed. 相似文献
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于2019年12月至2020年11月采用样线法对浙江省庆元县县域鸟的种类、生境、分布状况进行调查,本次调查共记录鸟类154种,隶属15目46科110属。鸟类物种组成以留鸟为主,其中留鸟93种(60.39%)、夏候鸟21种(13.64%)、冬候鸟21种(13.64%)、旅鸟19种(12.33%)。本次调查共记录到16种受威胁鸟类,鸟类资源的保护价值高。对空间分布格局分析表明,在水平方向上鸟类物种丰富度总体较高,百山祖国家公园(试点)内与国家公园(试点)外其他区域的物种数差异较小;在垂直方向上随着海拔的上升大致呈现先升高后下降的中峰模式。在调查样线的1 000 m缓冲尺度上,鸟类物种数和Pielou均匀度指数与灌丛面积占比呈显著正相关。各季节鸟类丰富度从高到低排序为:春季>秋季>夏季>冬季。本研究丰富了庆元县的鸟类本底资料,也为庆元县进行生物多样性保护决策提供了科学依据。 相似文献
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High-density interspecific genetic maps of kiwifruit and the identification of sex-specific markers 总被引:1,自引:0,他引:1
Qiong Zhang Chunyan Liu Yifei Liu Robert VanBuren Xiaohong Yao Caihong Zhong Hongwen Huang 《DNA research》2015,22(5):367-375
Kiwifruit (Actinidia chinensis Planchon) is an important specialty fruit crop that suffers from narrow genetic diversity stemming from recent global commercialization and limited cultivar improvement. Here, we present high-density RAD-seq-based genetic maps using an interspecific F1 cross between Actinidia rufa ‘MT570001’ and A. chinensis ‘Guihai No4’. The A. rufa (maternal) map consists of 2,426 single-nucleotide polymorphism (SNP) markers with a total length of 2,651 cM in 29 linkage groups (LGs) corresponding to the 29 chromosomes. The A. chinensis (paternal) map consists of 4,214 SNP markers over 3,142 cM in 29 LGs. Using these maps, we were able to anchor an additional 440 scaffolds from the kiwifruit draft genome assembly. Kiwifruit is functionally dioecious, which presents unique challenges for breeding and production. Three sex-specific simple sequence repeats (SSR) markers can be used to accurately sex type male and female kiwifruit in breeding programmes. The sex-determination region (SDR) in kiwifruit was narrowed to a 1-Mb subtelomeric region on chromosome 25. Localizing the SDR will expedite the discovery of genes controlling carpel abortion in males and pollen sterility in females. 相似文献
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810.
Ruiju Lu Yifei Wang Yuefang Sun Lili Shan Peidu Chen Jianhua Huang 《Plant Cell, Tissue and Organ Culture》2008,95(1):21-27
Barley microspores from five field-grown breeding lines were isolated using an ultra-speed blender and the effect of co-culture
with young florets was investigated. Floret co-culture in the induction stage increased the formation of MCS, ELS and green
plant regeneration. The florets of teraploid plant were more effective than ones of diploid plant. For line S23, co-culture
with florets from tetraploid plants gave rise to 2.6 and 7.8 times more MCS and ELS, respectively, than non-co-culture control,
whereas co-culture with florets from diploid plants resulted in 1.8 and 6.1 times more MCS and ELS, respectively, than non-co-culture
control (Table 2). Florets subjected to cold treatment for 10–20 days induced a greater response than fresh ones, and florets with uninucleate
microspores surpassed binucleate microspores. For microspores culture from 15-day cold pre-treated spikes, 93A floret co-culture
gave rise to 3.6 and 6.8 times more MCS and ELS, respectively, than the non-co-cultured control, while SD1 floret co-culture
resulted in 1.9 and 4.0 times more, respectively. Similarly, for microspore culture from 20-day cold pre-treated spikes, 93A
floret co-culture gave rise to 2.6 and 5.1 times more MCS and ELS, respectively, than non-co-cultured control, while SD1 floret
co-culture resulted in 1.5 and 3.0 times more, respectively (Table 3). Some microspores formed dense MCS that did not develop further. Compared with the control, floret co-culture resulted in
less dense MCS formation, indicating that the isolated florets were beneficial to the normal development of MCS. Floret co-culture
was only effective when the spikes were cold pre-treated before microspore isolation. Spike cold pre-treatment before microspore
preparation was crucial for dedifferentiation of cultured isolated microspores, and this could not be replaced by floret co-culture.
It is postulated that the florets provided essential substances for in vitro cultured isolated microspores to undergo dedifferentiation
and embryogenesis. Both the genotype selection and the physiological status (developmental status and cold treatment) adjustment
of the florets for co-culture could improve barley microspore culture. Compared with ovary co-culture, floret co-culture is
more efficient. The technique is of simple application in breeding programs and can be a solution for coping with recalcitrant
genotypes and or plant donor condition. 相似文献