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101.
102.
Tristan J. Iseli Nigel Turner Xiao-Yi Zeng Gregory J. Cooney Edward W. Kraegen Sheng Yao Yang Ye David E. James Ji-Ming Ye 《PloS one》2013,8(4)
We recently showed that bitter melon-derived triterpenoids (BMTs) activate AMPK and increase GLUT4 translocation to the plasma membrane in vitro, and improve glucose disposal in insulin resistant models in vivo. Here we interrogated the mechanism by which these novel compounds activate AMPK, a leading anti-diabetic drug target. BMTs did not activate AMPK directly in an allosteric manner as AMP or the Abbott compound (A-769662) does, nor did they activate AMPK by inhibiting cellular respiration like many commonly used anti-diabetic medications. BMTs increased AMPK activity in both L6 myotubes and LKB1-deficient HeLa cells by 20–35%. Incubation with the CaMKKβ inhibitor, STO-609, completely attenuated this effect suggesting a key role for CaMKKβ in this activation. Incubation of L6 myotubes with the calcium chelator EGTA-AM did not alter this activation suggesting that the BMT-dependent activation was Ca2+-independent. We therefore propose that CaMKKβ is a key upstream kinase for BMT-induced activation of AMPK. 相似文献
103.
104.
Ablation of rat myenteric plexus with benzalkonium chloride has provided a model of intestinal aganglionosis, but the degenerative
responses are not well understood. We examined the effects of this detergent on neurons and glia, including expression of
c-Myc, c-Jun, JunB, and c-Fos, and on immunocytes in the guinea-pig ileum. Benzalkonium chloride (0.1%) or saline was applied
to the serosal surface of distal ileum. Tissues were analyzed 2, 3, or 7 days later and compared with cyclosporine-treated
and untreated animals. More than 90% of myenteric neurons were destroyed in ileal segments 3–7 days after benzalkonium-chloride
treatment. Glia withdrew processes from around neurons after 2 days and were mostly gone after 3 days. Neuronal c-Myc began
to disappear while c-Fos, c-Jun, and JunB were evident in some neuronal nuclei after 2 or 3 days. After 3 days, widespread
apoptosis was evident in the myenteric plexus. Populations of T cells, B cells, and macrophage-like cells in untreated and
saline-treated myenteric plexuses were substantially increased 3 and 7 days after benzalkonium-chloride treatment. Cyclosporine
delayed significant neuronal loss. We conclude that a variety of degenerative mechanisms may be active in this model, including
an immune response which may actively contribute to tissue destruction.
Received: 13 September 1996 / Accepted: 20 January 1997 相似文献
105.
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108.
David A. Smith John L. Glover Laurace E. Townsend Diane E. Maupin 《In vitro cellular & developmental biology. Animal》1991,27(12):914-920
Summary Myocardial cell culture methods are now well established for animal and fetal human tissue. We present here a method for harvesting
and culturing adult human atrial myocardiocytes. Cells are obtained from fresh atrial tissue normally discarded after being
removed to cannulate the right atrium during open heart surgery. The atrial tissue is minced and then digested using collagenase.
The single cell suspension is initially cultured in serum-containing growth medium, then transferred to defined medium, selective
for myocardial cell growth. The cells are characterized by immunoperoxidase stains and transmission electron microscopy. The
cultured cells stain positive for myoglobin, whereas control cultured fibroblasts and endothelial cells do not. Electron microscopy
shows the presence of numerous myofibrils, Z-bodies, pleomorphic mitochondria, and secretory granules. The chronological age
of the donor was an important factor in culturing the adult tissue, the younger tissue correlated with a higher success rate.
This method provides a means for in vitro study of human adult myocardial cells and provides guidelines for appropriate atrial
tissue to use. 相似文献
109.
R. Smith 《BMJ (Clinical research ed.)》1994,309(6969):1644-1645
110.