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991.
A. Beqqali W. van Eldik C. Mummery R. Passier 《Cellular and molecular life sciences : CMLS》2009,66(5):800-813
Studies on identification, derivation and characterization of human stem cells in the last decade have led to high expectations
in the field of regenerative medicine. Although it is clear that for successful stem cell-based therapy several obstacles
have to be overcome, other opportunities lay ahead for the use of human stem cells. A more immediate application would be
the development of human models for cell-type specific differentiation and disease in vitro. Cardiomyocytes can be generated from stem cells, which have been shown to follow similar molecular events of cardiac development
in vivo. Furthermore, several monogenic cardiovascular diseases have been described, for which in vitro models in stem cells could be generated. Here, we will discuss the potential of human embryonic stem cells, cardiac stem
cells and the recently described induced pluripotent stem cells as models for cardiac differentiation and disease.
Received 07 August 2008; received after revision 26 September 2008; accepted 03 October 2008 相似文献
992.
A. Fridkin A. Penkner V. Jantsch Y. Gruenbaum 《Cellular and molecular life sciences : CMLS》2009,66(9):1518-1533
993.
R. P. Massengo-Tiassé J. E. Cronan 《Cellular and molecular life sciences : CMLS》2009,66(9):1507-1517
The enoyl-acyl carrier protein reductase (ENR) is the last enzyme in the fatty acid elongation cycle. Unlike most enzymes
in this essential pathway, ENR displays an unusual diversity among organisms. The growing interest in ENRs is mainly due to
the fact that a variety of both synthetic and natural antibacterial compounds are shown to specifically target their activity.
The primary anti-tuberculosis drug, isoniazid, and the broadly used antibacterial compound, triclosan, both target this enzyme.
In this review, we discuss the diversity of ENRs, and their inhibitors in the light of current research progress.
Received 3 November 2008; received after revision 5 December 2008; accepted 8 December 2008 相似文献
994.
I. Campia E. Gazzano G. Pescarmona D. Ghigo A. Bosia C. Riganti 《Cellular and molecular life sciences : CMLS》2009,66(9):1580-1594
Digoxin and ouabain are steroid drugs that inhibit the Na+/K+-ATPase, and are widely used in the treatment of heart diseases. They may also have additional effects, such as on metabolism
of steroid hormones, although until now no evidence has been provided about the effects of these cardioactive glycosides on
the synthesis of cholesterol. Here we report that digoxin and ouabain increased the synthesis of cholesterol in human liver
HepG2 cells, enhancing the activity and the expression of the
3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR), the rate-limiting enzyme of the cholesterol synthesis. This effect
was mediated by the binding of the sterol regulatory element binding protein-2 (SREBP-2) to the HMGCR promoter, and was lost
in cells silenced for SREBP-2 or loaded with increasing amounts of cholesterol. Digoxin and ouabain competed with cholesterol
for binding to the SREBP-cleavage-activating protein, and are critical regulators of cholesterol synthesis in human liver
cells.
Received 10 January 2009; received after revision 11 February 2009; accepted 6 March 2009 相似文献
995.
Ricardo F. Antunes Cláudia Brandão Gonçalo Carvalho Cristina Girão Fernando A. Arosa 《Cellular and molecular life sciences : CMLS》2009,66(20):3387-3398
Red blood cells (RBC) have emerged as a novel regulatory cell type endowed with bioactivities toward activated human T cells.
Herein we show that the RBC bioactivities act on intracellular pathways initiated by T cell receptor (TCR)-dependent and -independent
stimuli, including IL-2, IL-15, and the mixture of phorbol dibutyrate and ionomycin. The RBC bioactivities preserve the antioxidant
status and are capable of rescuing activated T cells from cell death induced by serum deprivation. They are not mediated by
glycosylphosphatidylinositol-linked receptors or sialic acids, and kinetic studies revealed that they hasten the entrance
into the cell cycle. By using cyclosporine A (CsA) and rapamycin (Rapa) we show that the RBC bioactivities are calcineurin-dependent.
Thus, treatment of T cells with CsA, but not Rapa, impaired RBC bioactivities, and preincubation of RBC with CsA completely
abolished their bioactivities. We have demonstrated that RBC carry out bioactivities that are sensitive to CsA. 相似文献
996.
Functions and pathologies of BiP and its interaction partners 总被引:1,自引:1,他引:0
J. Dudek J. Benedix S. Cappel M. Greiner C. Jalal L. Müller R. Zimmermann 《Cellular and molecular life sciences : CMLS》2009,66(9):1556-1569
The endoplasmic reticulum (ER) is involved in a variety of essential and interconnected processes in human cells, including
protein biogenesis, signal transduction, and calcium homeostasis. The central player in all these processes is the ER-lumenal
polypeptide chain binding protein BiP that acts as a molecular chaperone. BiP belongs to the heat shock protein 70 (Hsp70)
family and crucially depends on a number of interaction partners, including co-chaperones, nucleotide exchange factors, and
signaling molecules. In the course of the last five years, several diseases have been linked to BiP and its interaction partners,
such as a group of infectious diseases that are caused by Shigella toxin producing E. coli. Furthermore, the inherited diseases Marinesco-Sj?gren syndrome, autosomal dominant polycystic liver disease, Wolcott-Rallison
syndrome, and several cancer types can be considered BiP-related diseases. This review summarizes the physiological and pathophysiological
characteristics of BiP and its interaction partners.
Received 20 November 2008; received after revision 09 December 2008; accepted 12 December 2008 相似文献
997.
Carsten Lundby Jose A. L. Calbet Paul Robach 《Cellular and molecular life sciences : CMLS》2009,66(22):3615-3623
Hypoxia refers to environmental or clinical settings that potentially threaten tissue oxygen homeostasis. One unique aspect
of skeletal muscle is that, in addition to hypoxia, oxygen balance in this tissue may be further compromised when exercise
is superimposed on hypoxia. This review focuses on the cellular and molecular responses of human skeletal muscle to acute
and chronic hypoxia, with emphasis on physical exercise and training. Based on published work, it is suggested that hypoxia
does not appear to promote angiogenesis or to greatly alter oxidative enzymes in skeletal muscle at rest. Although the HIF-1
pathway in skeletal muscle is still poorly documented, emerging evidence suggests that muscle HIF-1 signaling is only activated
to a minor degree by hypoxia. On the other hand, combining hypoxia with exercise appears to improve some aspects of muscle
O2 transport and/or metabolism. 相似文献
998.
A. Shukla P. Chaurasia S. R. Bhaumik 《Cellular and molecular life sciences : CMLS》2009,66(8):1419-1433
Methylation of lysine residues of histones is associated with functionally distinct regions of chromatin, and, therefore,
is an important epigenetic mark. Over the past few years, several enzymes that catalyze this covalent modification on different
lysine residues of histones have been discovered. Intriguingly, histone lysine methylation has also been shown to be cross-regulated
by histone ubiquitination or the enzymes that catalyze this modification. These covalent modifications and their cross-talks
play important roles in regulation of gene expression, heterochromatin formation, genome stability, and cancer. Thus, there
has been a very rapid progress within past several years towards elucidating the molecular basis of histone lysine methylation
and ubiquitination, and their aberrations in human diseases. Here, we discuss these covalent modifications with their cross-regulation
and roles in controlling gene expression and stability.
Received 24 September 2008; received after revision 21 November 2008; accepted 28 November 2008 相似文献
999.
The elucidation of assembly pathways of multi-subunit membrane proteins is of growing interest in structural biology. In this
study, we provide an analysis of the assembly of the asymmetrically oriented PsaC subunit on the pseudo C2-symmetric Photosystem I core. Based on a comparison of the differences in the NMR solution structure of unbound PsaC with
that of the X-ray crystal structure of bound PsaC, and on a detailed analysis of the PsaC binding site surrounding the FX iron-sulfur cluster, two models can be envisioned for what are likely the last steps in the assembly of Photosystem I. Here,
we dissect both models and attempt to address heretofore unrecognized issues by proposing a mechanism that includes a thermodynamic
perspective. Experimental strategies to verify the models are proposed. In closing, the evolutionary aspects of the assembly
process will be considered, with special reference to the structural arrangement of the PsaC binding surface.
Received 22 October 2008; received after revision 17 November 2008; accepted 05 December 2008 相似文献
1000.
借鉴经典动力学中约束力的思想,提出了一种编队卫星构形精确保持的非线性控制方法.该方法首先将非线性和摄动条件下编队卫星构形保持问题转换为带有完整约束的拉格朗日动力学系统,然后将问题转换为一组微分代数方程,通过求解微分代数方程,确定编队卫星构形保持的非线性控制律.由于借鉴了约束力的思想,该方法自然地利用了编队卫星动力学系统的力学特性,具有节省能量和高精度的特点.通过对线性和非线性条件下空间圆编队卫星构形保持问题的仿真,验证了提出的非线性控制方法的这些特性. 相似文献