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21.
Brassica rapa L., also called NIUMA, is used empirically in Tibetan medicine for its antioxidant, anti‐inflammatory and antiradiation activities. This study explored the hepatoprotective effects of B. rapa polysaccharides (BRPs) on acute liver injury induced by carbon tetrachloride (CCl4) in mice and the underlying mechanisms. Mice were treated with CCl4 after the oral administration of BRPs (55, 110 and 220 mg/kg) or bifendate (100 mg/kg) for 7 days. Blood and liver samples of mice were collected for analysis after 24 h. The ALP, ALT and AST levels and the biological activities of SOD, MDA and GSH?Px were measured. Histopathological changes in the liver were determined through hematoxylin and eosin staining. Moreover, TNF‐α, IL‐1β and IL‐6 expression levels were detected by commercial reagent kits. Finally, Western blot analysis was used to check the relative expression levels of caspase‐3, p‐JAK2 and p‐STAT3. The BRP pre‐treatment significantly decreased the enzymatic activities of ALT, ALP and AST in the serum, markedly increased the activities of SOD and GSH?Px in the liver and reduced the MDA concentration in the liver. BRPs alleviated hepatocyte injury and markedly inhibited the expression of TNF‐α, IL‐1β and IL‐6, also downregulating the CCl4‐induced hepatic tissue expression of caspase‐3. Furthermore, BRPs inhibited the JAK2/STAT3 signaling pathway in a dose‐dependent manner in the liver. This study demonstrated that BRPs exert hepatoprotective effect against the CCl4‐induced liver injury via modulating the apoptotic and inflammatory responses and downregulating the JAK2/STAT3 signaling pathway. Therefore, B. rapa could be considered a hepatoprotective medicine.  相似文献   
22.
Cardiac vascular microenvironment is crucial for cardiac remodelling during the process of heart failure. Sphingosine 1‐phosphate (S1P) tightly regulates vascular homeostasis via its receptor, S1pr1. We therefore hypothesize that endothelial S1pr1 might be involved in pathological cardiac remodelling. In this study, heart failure was induced by transverse aortic constriction (TAC) operation. S1pr1 expression is significantly increased in microvascular endothelial cells (ECs) of post‐TAC hearts. Endothelial‐specific deletion of S1pr1 significantly aggravated cardiac dysfunction and deteriorated cardiac hypertrophy and fibrosis in myocardium. In vitro experiments demonstrated that S1P/S1pr1 praxis activated AKT/eNOS signalling pathway, leading to more production of nitric oxide (NO), which is an essential cardiac protective factor. Inhibition of AKT/eNOS pathway reversed the inhibitory effect of EC‐S1pr1‐overexpression on angiotensin II (AngII)‐induced cardiomyocyte (CM) hypertrophy, as well as on TGF‐β‐mediated cardiac fibroblast proliferation and transformation towards myofibroblasts. Finally, pharmacological activation of S1pr1 ameliorated TAC‐induced cardiac hypertrophy and fibrosis, leading to an improvement in cardiac function. Together, our results suggest that EC‐S1pr1 might prevent the development of pressure overload‐induced heart failure via AKT/eNOS pathway, and thus pharmacological activation of S1pr1 or EC‐targeting S1pr1‐AKT‐eNOS pathway could provide a future novel therapy to improve cardiac function during heart failure development.  相似文献   
23.
Natural products were extracted from traditional Chinese herbal emerging as potential therapeutic drugs for treating cardiovascular diseases. This study examines the role and underlying mechanism of dihydromyricetin (DMY), a natural compound extracted from Ampelopsis grossedentata, in atherosclerosis. DMY treatment significantly inhibits atherosclerotic lesion formation, proinflammatory gene expression and the influx of lesional macrophages and CD4-positive T cells in the vessel wall and hepatic inflammation, whereas increases nitric oxide (NO) production and improves lipid metabolism in apolipoprotein E-deficient (Apoe/) mice. Yet, those protective effects are abrogated by using NOS inhibitor L-NAME in Apoe/ mice received DMY. Mechanistically, DMY decreases microRNA-21 (miR-21) and increases its target gene dimethylarginine dimethylaminohydrolase-1 (DDAH1) expression, an effect that reduces asymmetric aimethlarginine (ADMA) levels, and increases endothelial NO synthase (eNOS) phosphorylation and NO production in cultured HUVECs, vascular endothelium of atherosclerotic lesions and liver. In contrast, systemic delivery of miR-21 in Apoe/ mice or miR-21 overexpression in cultured HUVECs abrogates those DMY-mediated protective effects. These data demonstrate that endothelial miR-21-inhibited DDAH1-ADMA-eNOS-NO pathway promotes the pathogenesis of atherosclerosis which can be rescued by DMY. Thus, DMY may represent a potential therapeutic adjuvant in atherosclerosis management.  相似文献   
24.
Halide perovskite materials have achieved overwhelming success in various optoelectronic applications, especially perovskite solar cells and perovskite‐based light‐emitting diodes (P‐LEDs), owing to their outstanding optical and electric properties. It is widely believed that flat and mirror‐like perovskite films are imperative for achieving high device performance, while the potential of other perovskite morphologies, such as the emerging textured perovskite, is overlooked, which leaves plenty of room for further breakthroughs. Compared to flat and mirror‐like perovskites, textured perovskites with unique structures, e.g., coral‐like, maze‐like, column‐like or quasi‐core@shell assemblies, are more efficient at light harvesting and charge extraction, thus revolutionizing the pathways toward ultrahigh performance in perovskite‐based optoelectronic devices. Employing a textured perovskite morphology, the record of external quantum efficiency for P‐LEDs is demonstrated as 21.6%. In this research news, recent progress in the utilization of textured perovskite is summarized, with the emphasis on the preparation strategies and prominent optoelectronic properties. The impact of the textured morphology on light harvesting, carrier dynamic management, and device performance is highlighted. Finally, the challenges and great potential of employing these innovative morphologies in fabricating more efficient optoelectronic devices, or creating a new energy harvesting and conversion regime are also provided.  相似文献   
25.
26.
Changes in mitochondrial dynamics (fusion and fission) are known to occur during stem cell differentiation; however, the role of this phenomenon in tissue aging remains unclear. Here, we report that mitochondrial dynamics are shifted toward fission during aging of Drosophila ovarian germline stem cells (GSCs), and this shift contributes to aging‐related GSC loss. We found that as GSCs age, mitochondrial fragmentation and expression of the mitochondrial fission regulator, Dynamin‐related protein (Drp1), are both increased, while mitochondrial membrane potential is reduced. Moreover, preventing mitochondrial fusion in GSCs results in highly fragmented depolarized mitochondria, decreased BMP stemness signaling, impaired fatty acid metabolism, and GSC loss. Conversely, forcing mitochondrial elongation promotes GSC attachment to the niche. Importantly, maintenance of aging GSCs can be enhanced by suppressing Drp1 expression to prevent mitochondrial fission or treating with rapamycin, which is known to promote autophagy via TOR inhibition. Overall, our results show that mitochondrial dynamics are altered during physiological aging, affecting stem cell homeostasis via coordinated changes in stemness signaling, niche contact, and cellular metabolism. Such effects may also be highly relevant to other stem cell types and aging‐induced tissue degeneration.  相似文献   
27.
Kuang  Cheng-Hao  Zhao  Xiao-Fang  Yang  Ke  Zhang  Zhi-Peng  Ding  Li  Pu  Zhi-En  Ma  Jian  Jiang  Qian-Tao  Chen  Guo-Yue  Wang  Ji-Rui  Wei  Yu-Ming  Zheng  You-Liang  Li  Wei 《Physiology and Molecular Biology of Plants》2020,26(6):1295-1307
Physiology and Molecular Biology of Plants - The spike traits of wheat can directly affect yield. F2 and F2:3 lines derived from the cross of the multi-spikelet female 10-A and the uni-spikelet...  相似文献   
28.
Kuang  Wenzhong  Liu  Chen  Xu  Hongguang 《Cytotechnology》2021,73(3):447-456
Cytotechnology - Low back pain caused by intervertebral disc degeneration has become a global problem that seriously affects public health. The application of nucleus pulposus tissue engineering to...  相似文献   
29.
Ptk2b has been found playing critical roles in oocyte maturation and subsequent fertilization in vitro. But what is the exact in vivo function in reproduction still elusive. Here, by constructing Ptk2b mutant mice, we found Ptk2b was not essential for mice fertility, unexpectedly, contrary to previously reported in vitro findings, we found Ptk2b ablation significantly improved female fecundity. Follicle counting indicated that the number of primordial follicles and growing follicles in matured mice was significantly increased in the absence of Ptk2b, whereas the primordial follicle formation showed no defects. We also found this regulation was in an autophosphorylation independent pathway, as autophosphorylation site mutant mice (PTK2BY402F) show no phenotype in female fertility. Further biochemistry studies revealed that Ptk2b ablation promotes folliculogenesis via Erk pathway mediate follicle survival. Together, we found a novel biological function of Ptk2b in folliculogenesis, which could be potentially used as a therapeutic target for corresponding infertility.  相似文献   
30.
Photosystem I (PSI) is one of the two photosystems in photosynthesis, and performs a series of electron transfer reactions leading to the reduction of ferredoxin. In higher plants, PSI is surrounded by four light-harvesting complex I (LHCI) subunits, which harvest and transfer energy efficiently to the PSI core. The crystal structure of PSI-LHCI supercomplex has been analyzed up to 2.6 Å resolution, providing much information on the arrangement of proteins and cofactors in this complicated supercomplex. Here we have optimized crystallization conditions, and analyzed the crystal structure of PSI-LHCI at 2.4 Å resolution. Our structure showed some shift of the LHCI, especially the Lhca4 subunit, away from the PSI core, suggesting the indirect connection and inefficiency of energy transfer from this Lhca subunit to the PSI core. We identified five new lipids in the structure, most of them are located in the gap region between the Lhca subunits and the PSI core. These lipid molecules may play important roles in binding of the Lhca subunits to the core, as well as in the assembly of the supercomplex. The present results thus provide novel information for the elucidation of the mechanisms for the light-energy harvesting, transfer and assembly of this supercomplex.  相似文献   
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