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Tendon stem/progenitor cell (TSPC) senescence may lead to age-related tendon disorders and impair tendon regeneration and replacement capacity in humans. However, the mechanisms governing TSPC aging and degeneration remain obscure. Recently, it has been reported that Rho-associated coiled-coil protein kinase 1 (ROCK1) might be a key player in TSPC aging process. miRNAs are also involved in cellular senescence. In this study, whether miRNAs modulate senescence of TSPCs through targeting ROCK1 was evaluated. We found that miR-135a, which directly binds to the 3′-untranslated region of ROCK1, is significantly downregulated in aged compared with young TSPCs. Overexpression of miR-135a in young TSPCs suppresses senescence, promotes proliferation, and induces migration and tenogenic differentiation, whereas suppression of miR-135a in aged TSPCs has the opposite effects. By gain-of-function and loss-of-function studies, we confirmed that ROCK1 mediates the effects of miR-135a in TSPCs. Taken together, our data suggest that miR-135a plays an important role in TSPC senescence via targeting ROCK1. [ABSTRACT FROM AUTHOR]

Abstract: Four new sesquiterpenes (1–4), together with four known compounds (5–8), were isolated from the stems of Pogostemon cablin (Blanco.) Benth. Their chemical structures were elucidated by means of spectroscopic methods, including 1D and 2D NMR, HRESIMS, IR, and UV. Hepatoprotective activities of these compounds were investigated, by studying the protective effect on HL-7702 cellular injury induced by dl-galactosamine. [Copyright &y& Elsevier]

In chemical EOR (especially polymer flooding), the swept area and oil recovery of displacing fluids were strongly affected by reservoir heterogeneity. To qualitatively study and discuss the oil reservoir heterogeneity control capacity of a new water-soluble polymer, associative polymer (AP-X), this work, compared with HPAM, conducted a series of laboratory experiments involving apparent viscosity, fluorescence, rheological properties, threshold pressure, flow and transport in porous media, as well as the oil micro-/macro-displacements in interstratified connected and parallel heterogenous micro-/macro-models. The results showed that AP-X had more significant thickening capacity and viscoelasticity than HPAM and presented noticeable self-association effect due to the associative interaction between hydrophobic groups. To enter into the porous media with the same or higher permeability, AP-X needed much greater injection (threshold) pressure than HPAM although the threshold pressure of AP-X significantly decreased as increasing permeability. More importantly, AP-X could not only present a good conductivity but also establish significantly higher flow resistance. In addition, at a greater permeability contrast of 8 times (8000/1000 mD), AP-X mainly swept the high permeable layer and slightly swept the low permeable layer slowly within 0.5 PV, which was accompanied by the significant sweep for the low layer after 0.5 PV. More interestingly, AP-X could also make the fluid diversion of the post-water to further mobilize the oil in low permeable layer and obtain a higher EOR than HPAM. All results indicate that associative polymer has remarkable application potential and advantages than HPAM in EOR not only regarding to better thickening property and viscoelasticity but also involving higher flow resistance and significant heterogeneity control capacity, which can provide a new system design concept and technical ideas for reservoir heterogeneity control. • The gel-like property of associative polymer implies the potential for heterogeneity control. • Associative polymer could not only present a good conductivity but also establish significantly higher flow resistance. • Associative polymer could achieve the fluid diversion of the post-water to efficiently mobilize oil in low permeable layer. • Associative polymer could provide a new system design concept and technical ideas for reservoir heterogeneity control. [ABSTRACT FROM AUTHOR]