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991.
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993.
Scott B. Widenmaier Su-Jin Kim Gary K. Yang Thomas De Los Reyes Cuilan Nian Ali Asadi Yutaka Seino Timothy J. Kieffer Yin Nam Kwok Christopher H. S. McIntosh 《PloS one》2010,5(3)
Aims
The gastrointestinal hormone GIP promotes pancreatic islet function and exerts pro-survival actions on cultured β-cells. However, GIP also promotes lipogenesis, thus potentially restricting its therapeutic use. The current studies evaluated the effects of a truncated GIP analog, D-Ala2-GIP1–30 (D-GIP1–30), on glucose homeostasis and β-cell mass in rat models of diabetes.Materials and Methods
The insulinotropic and pro-survival potency of D-GIP1–30 was evaluated in perfused pancreas preparations and cultured INS-1 β-cells, respectively, and receptor selectivity evaluated using wild type and GIP receptor knockout mice. Effects of D-GIP1–30 on β-cell function and glucose homeostasis, in vivo, were determined using Lean Zucker rats, obese Vancouver diabetic fatty rats, streptozotocin treated rats, and obese Zucker diabetic fatty rats, with effects on β-cell mass determined in histological studies of pancreatic tissue. Lipogenic effects of D-GIP1–30 were evaluated on cultured 3T3-L1 adipocytes.Results
Acutely, D-GIP1–30 improved glucose tolerance and insulin secretion. Chronic treatment with D-GIP1–30 reduced levels of islet pro-apoptotic proteins in Vancouver diabetic fatty rats and preserved β-cell mass in streptozotocin treated rats and Zucker diabetic fatty rats, resulting in improved insulin responses and glycemic control in each animal model, with no change in body weight. In in vitro studies, D-GIP1–30 exhibited equivalent potency to GIP1–42 on β-cell function and survival, but greatly reduced action on lipoprotein lipase activity in 3T3-L1 adipocytes.Conclusions
These findings demonstrate that truncated forms of GIP exhibit potent anti-diabetic actions, without pro-obesity effects, and that the C-terminus contributes to the lipogenic actions of GIP. 相似文献994.
Sameh Magdeldin Huiping Li Yutaka Yoshida Shymaa Enany Ying Zhang Bo Xu Hidehiko Fujinaka Eishin Yaoita Tadashi Yamamoto 《Journal of Proteomics》2010,73(10):2031-2040
Aquaporin (AQP) family plays a fundamental role in transmembrane water and small solutes movement. Within this family, aquaporin 8 (AQP8), showed to be widely distributed in the digestive system especially colon. To investigate the possible protein alterations involved in AQP8 regulation and trafficking, we extensively compared between wild type and AQP8 knockout mouse colon using semi-quantitative fluorescence- stained two dimensional gel electrophoresis (2-DE) coupled with nano LC-Ms/Ms. Our analysis revealed identification and regulation of 21 proteins, most notably, actin-related family which suggests its possible involvement in regulating AQP8 secretory vesicles migration to be integrated as a cell membrane protein. 相似文献
995.
996.
Increased bone resorption mediated by osteoclasts causes various diseases such as osteoporosis and bone erosion in rheumatoid
arthritis (RA). Osteoclasts are derived from the monocyte/macrophage lineage, but the precise origin remains unclear. In the
present study, we show that the purified CD16- human peripheral blood monocyte subset, but not the CD16+ monocyte subset, differentiates into osteoclast by stimulation with receptor activator of NF-κB ligand (RANKL) in combination
with macrophage colony-stimulating factor (M-CSF). Integrin-β3 mRNA and the integrin-αvβ3 heterodimer were only expressed
on CD16- monocytes, when they were stimulated with RANKL + M-CSF. Downregulation of β3-subunit expression by small interfering RNA
targeting β3 abrogated osteoclastogenesis from the CD16- monocyte subset. In contrast, the CD16+ monocyte subset expressed larger amounts of tumor necrosis factor alpha and IL-6 than the CD16- subset, which was further enhanced by RANKL stimulation. Examination of RA synovial tissue showed accumulation of both CD16+ and CD16- macrophages. Our results suggest that peripheral blood monocytes consist of two functionally heterogeneous subsets with distinct
responses to RANKL. Osteoclasts seem to originate from CD16- monocytes, and integrin β3 is necessary for osteoclastogenesis. Blockade of accumulation and activation of CD16- monocytes could therefore be a beneficial approach as an anti-bone resorptive therapy, especially for RA. 相似文献
997.
Control of nanostructure formation by a diblock-type supramacromolecule via biocomplementary hydrogen bonding has been achieved. Two different homopolymers, poly(4-trimethylsilylstyrene) and poly(styrene-d8), that are end-decorated with complementary oligonucleotides, i.e., thymidine phosphates and deoxyadenosine phosphates, were prepared by using the phosphoramidite method and blended successively. Association behavior in a blend solution was examined with NMR, and a cast bulk film obtained from the solution has been confirmed to show a nanophase-separated structure by transmission electron microscopy and X-ray scattering. Suppression of this nanostructure formation of a block-type supramacromolecule was also attained by adding a smaller agent as an inhibitor. 相似文献
998.
Hoy Taek Kim Gen Hattori Yutaka Hirata Dae Ill Kim Jeong Hwan Hwang Yong Uk Shin Ill Sup Nou 《Journal of Plant Biology》2006,49(6):448-454
To prevent self-fertilization, apple has a gametophytic self-incompatibility mechanism, part of a widespread intraspecific
system, that is controlled by a multi-allelic locus. This attribute has been exploited in breeding programs for new cultivars.
Likewise, many apple orchards depend on artificial pollination. Therefore, molecular analysis and early identification of
the self-incompatibility (S) genotype could greatly improve breeding schemes and pollen donors selection. Here, we PCR-amplified
the S-RNase PCR fragments from a total of 14 cultivars and parents, using new primers (ASPF3+ASPR3) common to 23 S-alleles
in apple. The S-genotypes were determined for the following: ‘Hongro’ (S1S3), ‘Gamhong’ (S1S9), ‘Saenara’ (S1S3), ‘Chukwang’ (S3S9), ‘Hwahong’ (S3S9), ‘Seokwang’ (S3S3), ‘Hwarang’ (S1S9), ‘Sunhong’ (S3S9), ‘S.E.B.’ (S1S19), ‘S.G.D.’ (S2S3), and ‘Mollie’s Delicious’ (S3S7). We also confirmed the characteristics of the S-genotypes for eight Korean apple cultivars by PCR-Southern blot analysis,
using seven S-RNases as probes. 相似文献
999.
Keisuke Obase Takahito Kobayashi Toshizumi Miyamoto Yutaka Tamai Takashi Yajima 《Mycoscience》2006,47(5):293-297
A species of the genus Inocybe, which has not been recorded previously in Japan, is described and illustrated as a new record. Inocybe nitidiuscula (Britzelm.) Sacc. belongs to the subgenus Inocibium (Earle) Singer. 相似文献
1000.
Asaoka N Tanaka Y Sakai T Fujii Y Ohuchi R Ohuchi M 《Microbes and infection / Institut Pasteur》2006,8(2):511-519
Madin Darby canine kidney (MDCK) cells have generally been used to isolate influenza viruses from patients. However, in recent years, most fresh isolates of the H3N2 subtype have shown poor growth in MDCK cell cultures. Such low-growth viruses were often converted to high-growth viruses after several passages through MDCK cell cultures. In the present study, viruses were found to lose a potential glycosylation site near the receptor-binding pocket of hemagglutinin (HA), at the same time as they acquired the high-growth property. The growth curves of viruses in MDCK cell cultures revealed that multi-cycle replication did not function well in the low-growth viruses. However, the production of progeny viruses within a single cycle of growth did not differ much between the low- and high-growth viruses. The high-growth viruses showed higher infection efficiency in MDCK cell cultures than the low-growth viruses. The HA genes of both low- and high-growth viruses were separately cloned into the SV40 vector to compare their receptor binding affinities. The HA of high-growth viruses showed a much higher receptor binding affinity than that of low-growth viruses, when assayed by hemadsorption and the release kinetics of erythrocytes with bacterial neuraminidase. Reverse genetics studies demonstrated that HA was a crucial determinant for multi-cycle replication in MDCK cell cultures. Taken together, these results demonstrate that inefficient multi-cycle growth of fresh isolates is due to their low receptor binding affinities. 相似文献