ABSTRACT
Cell mechanics is a new interdiscipline, which focuses on the relationship between cell mechanical properties and cell behaviors, as well as physiological processes in tissues, organs and the body. Through the perception of and response to mechanical signals, cells participate in physiological activities of skin, bones, eyes and other organs, and the occurrence and development of diseases, including the regeneration, reconstruction and adaptive changes of skin tissues and the pathogenesis of various skin diseases. Cell mechanics has become a hot spot in the research of skin diseases in recent years. This review summarizes recent progress in cell mechanics-associated basic research, as well as in its research and application in scars, bedsores, vitiligo, skin tumors, hair diseases, etc., aiming to provide possible methods and strategies for the treatment of skin diseases.
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Advanced glycation end-products (AGEs) are the products of non-enzymatic reactions between free amino groups of macromolecules and reducing sugars. AGEs accumulation in bone tissues changes the activity and function of bone cells by binding to their surface receptors, causing abnormalities in the process of bone remodeling. AGEs accumulation can also change the original structure and mineral deposition of bone collagen, affect the micro-mechanical properties of bone tissues, and further reduce bone strength and toughness, increase the bone fracture risk, which will lead to bone diseases and do great harm to human health. This article summarized the causes of AGEs and their detection methods, and reviewed previous studies about the effects of AGEs accumulation on bone biomechanics at micro and macro levels, so as to provide references for the early diagnosis and treatment of bone diseases in clinic.
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Objective To study the effect of simulated microgravity on activity of the store-operated calcium (SOC) channels in osteocytes and its possible mechanism, so as to elucidate the potential mechanism of weightlessness bone loss. Methods Osteocytes (MLO-Y4) as the experimental subjects were divided into simulated microgravity (SM) group and normal gravity group (CON). After rotating for 24 h and 48 h, confocal microscope was used to detect the intracellular calcium ion concentration level to reflect activity of the SOC channels after thapsigargin (TG)-induced endoplasmic reticulum (ER) depletion. Immunofluorescence staining was used to observe the distribution of ER membrane protein IP3R and spectrin membrane skeleton, in order to preliminarily explore the possible mechanism of functional changes of SOC channels. Results During the period of calcium release from ER, ［Ca2+］i had no significant difference between SM group and CON group for 24 h and 48 h; while during the period of extracellular calcium influx by SOC channels, ［Ca2+］i of SM group had significant differences in the first 4 minutes for 24 h, as well as in the whole time for 48 h. Compared with CON group, the spectrin membrane skeleton of SM group was gathered at the rim of membrane, while ER membrane protein IP3R of SM group was gathered at the nuclear envelope of ER. These two tendencies were more obvious for 48 h. Conclusions The stimulated microgravity could inhibit activity of SOC channels in osteocytes. Changes in the distribution of the spectrin membrane skeleton and ER membrane protein IP3R under the simulated microgravity might reduce the activity of SOC channels by affecting the conformation coupling process between the membrane and ER.
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Polydimethylsiloxane (PDMS) and hydroxyapatite (HA) were combined in our laboratory to fabricate an elastic porous cell scaffold with pore-forming agent, and then the scaffold was used as culture media for rat bone marrow derived mesenchymal stem cells (rBMSCs). Different porous materials (square and circular in shape) were prepared by different pore-forming agents (NaCl or paraffin spheres) with adjustable porosity (62%-76%). The HA crystals grew on the wall of hole when the material was exposed to SBF solutions, showing its biocompatibility and ability to support the cells to attach on the materials.
Subject(s)
Animals , Rats , Biocompatible Materials , Chemistry , Dimethylpolysiloxanes , Chemistry , Durapatite , Chemistry , Mesenchymal Stem Cells , Cell Biology , Porosity , Tissue ScaffoldsABSTRACT
Objective To investigate the effects of some compounds,bestatin,tripdiolide,etc,on leukotriene A4hydrolase activity.Methods LTB4,product of leukotriene A4hydrolase,was determined by reverse phase high performance liquid chromatography(PR-HPLC).Bestatin,an inhibitor of LTA4hydrolase was used as a positive control.Results Tripdiolide could inhibit LTA4hydrolase activity in a dose-depen-dent pattern.The50%inhibitory concentration values(IC 50 )was2.58?10 -5 ?g/mL.The other compounds,an-thralin,cyclosporin A,tretinoin,calcipotriene,clobetasol propionate,methotrexate,and erythromycin,had no effects.Conclusions Tripdiolide possibly has anti-inflammatory effect through down-regulation of leukotriene A4hydrolase in psoriasis.
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Objective To Investigate the effects of antipsoriatic drugs on 5 lipoxygenase(5－LO) and set up a relevant pharmacodynamic method. Methods 5－ LO products, leukotriene B4 (LTB4) and 5 hydroxyeicosatetraenoic(5－HETE), we re determined by RP－HPLC to represent 5－LO activity. Results Cyclosporin A( CyA) and triptolide(T0) inhibited the production of LTB4 and 5－HETE in a dose dependent manner, while erythromycin did without dose dependence. The 50％ inhibitory concentration values(IC50) of CyA inhibiting LTB4 and 5－HETE were 3 8.0? g/mL and 0.96? g/mL, respectively. The IC50 of T0 inhibiting LTB4 and 5－ HETE were 2.3? 10－6? g/mL and 1.14? 10－6? g/mL, respectively. Conclusio ns The anti inflammatory effect of Tripterygium wilfordii Hook.f. may be partl y explained by its inhibition of 5－LO activity. The anti inflammatory effect of CyA has no clinical significance since the inhibitory concentration of CyA h as exceeded its pharmacological limitation. Erythromycin has no effect on 5－LO activity.