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931.
932.
The maintenance of mucosal barrier equilibrium in the intestine requires a delicate and dynamic balance between enterocyte
loss by apoptosis and the generation of new cells by proliferation from stem cell precursors at the base of the intestinal
crypts. When the balance shifts towards either excessive or insufficient apoptosis, a broad range of gastrointestinal diseases
can manifest. Recent work from a variety of laboratories has provided evidence in support of a role for receptors of the innate
immune system, including Toll-like receptors 2, 4, and 9 as well as the intracellular pathogen recognition receptor NOD2/CARD15,
in the initiation of enterocyte apoptosis. The subsequent induction of enterocyte apoptosis in response to the activation
of these innate immune receptors plays a key role in the development of various intestinal diseases, including necrotizing
enterocolitis, Crohn’s disease, ulcerative colitis, and intestinal cancer. This review will detail the regulatory pathways
that govern enterocyte apoptosis, and will explore the role of the innate immune system in the induction of enterocyte apoptosis
in gastrointestinal disease. 相似文献
933.
Oleksiewicz U Liloglou T Field JK Xinarianos G 《Cellular and molecular life sciences : CMLS》2011,68(23):3869-3883
Since the discovery of cytoglobin (Cygb) a decade ago, growing amounts of data have been gathered to characterise Cygb biochemistry,
functioning and implication in human pathologies. Its molecular roles remain under investigation, but nitric oxide dioxygenase
and lipid peroxidase activities have been demonstrated. Cygb expression increases in response to various stress conditions
including hypoxia, oxidative stress and fibrotic stimulation. When exogenously overexpressed, Cygb revealed cytoprotection
against these factors. Cygb was shown to be upregulated in fibrosis and neurodegenerative disorders and downregulated in multiple
cancer types. CYGB was also found within the minimal region of a hereditary tylosis with oesophageal cancer syndrome, and its expression was
reduced in tylotic samples. Recently, Cygb has been shown to inhibit cancer cell growth in vitro, thus confirming its suggested
tumour suppressor role. This article aims to review the biochemical and functional aspects of Cygb, its involvement in various
pathological conditions and potential clinical utility. 相似文献
934.
Lubka-Pathak M Shah AA Gallozzi M Müller M Zimmermann U Löwenheim H Pfister M Knipper M Blin N Schimmang T 《Cellular and molecular life sciences : CMLS》2011,68(16):2739-2749
Introduction
Tff3 peptide exerts important functions in cytoprotection and restitution of the gastrointestinal (GI) tract epithelia. Moreover, its presence in the rodent inner ear and involvement in the hearing process was demonstrated recently. However, its role in the auditory system still remains elusive. Our previous results showed a deterioration of hearing with age in Tff3-deficient animals.Results
Present detailed analysis of auditory brain stem response (ABR) measurements and immunohistochemical study of selected functional proteins indicated a normal function and phenotype of the cochlea in Tff3 mutants. However, a microarray-based screening of tissue derived from the auditory central nervous system revealed an alteration of securin (Pttg1) and serpina3n expression between wild-type and Tff3 knock-out animals. This was confirmed by qRT-PCR, immunostaining and western blots.Conclusions
We found highly down-regulated Pttg1 and up-regulated serpina3n expression as a consequence of genetically deleting Tff3 in mice, indicating a potential role of these factors during the development of presbyacusis. 相似文献935.
Biological cells harbor a variety of molecular machines that carry out mechanical work at the nanoscale. One of these nanomachines
is the bacterial motor protein SecA which translocates secretory proteins through the protein-conducting membrane channel
SecYEG. SecA converts chemically stored energy in the form of ATP into a mechanical force to drive polypeptide transport through
SecYEG and across the cytoplasmic membrane. In order to accommodate a translocating polypeptide chain and to release transmembrane
segments of membrane proteins into the lipid bilayer, SecYEG needs to open its central channel and the lateral gate. Recent
crystal structures provide a detailed insight into the rearrangements required for channel opening. Here, we review our current
understanding of the mode of operation of the SecA motor protein in concert with the dynamic SecYEG channel. We conclude with
a new model for SecA-mediated protein translocation that unifies previous conflicting data. 相似文献
936.
Yvonne G. J. van Helden Roger W. L. Godschalk Hans J. M. Swarts Peter C. H. Hollman Frederik J. van Schooten Jaap Keijer 《Cellular and molecular life sciences : CMLS》2011,68(3):489-504
Molecular mechanisms triggered by high dietary beta-carotene (BC) intake in lung are largely unknown. We performed microarray
gene expression analysis on lung tissue of BC supplemented beta-carotene 15,15′-monooxygenase 1 knockout (Bcmo1
−/−) mice, which are—like humans—able to accumulate BC. Our main observation was that the genes were regulated in an opposite direction in male and female Bcmo1
−/− mice by BC. The steroid biosynthetic pathway was overrepresented in BC-supplemented male Bcmo1
−/− mice. Testosterone levels were higher after BC supplementation only in Bcmo1
−/− mice, which had, unlike wild-type (Bcmo1
+/+) mice, large variations. We hypothesize that BC possibly affects hormone synthesis or metabolism. Since sex hormones influence
lung cancer risk, these data might contribute to an explanation for the previously found increased lung cancer risk after
BC supplementation (ATBC and CARET studies). Moreover, effects of BC may depend on the presence of frequent human BCMO1 polymorphisms, since these effects were not found in wild-type mice. 相似文献
937.
The skin is our primary shield against microbial pathogens and has evolved innate and adaptive strategies to enhance immunity
in response to injury or microbial insult. The study of antimicrobial peptide (AMP) production in mammalian skin has revealed
several of the elegant strategies that AMPs use to prevent infection. AMPs are inducible by both infection and injury and
protect the host by directly killing pathogens and/or acting as multifunctional effector molecules that trigger cellular responses
to aid in the anti-infective and repair response. Depending on the specific AMP, these molecules can influence cytokine production,
cell migration, cell proliferation, differentiation, angiogenesis and wound healing. Abnormal production of AMPs has been
associated with the pathogenesis of several cutaneous diseases and plays a role in determining a patient’s susceptibility
to pathogens. This review will discuss current research on the regulation and function of AMPs in the skin and in skin disorders. 相似文献
938.
F.A.Zhang L.Chen J.Q.Ma X.Yang 《复旦学报(自然科学版)》2007,46(5)
1 Results Nanocomposite has attracted more and more interest all over the world.Polystyrene (PS) is a commercialized and mass-productive polymer,continuous research efforts have been devoted to the development of polystyrene/montmorillonite (PS/MMT) nanocomposites[1-2].But the polarity of styrene (St) is too small to intercalate the space between the clay layers.The polarity of hydrophilic monomer is so strong that it can intercalate the MMT easily,the intercalated smectic clays maybe exfoliated by usin... 相似文献
939.
940.
采用积分电路的方法对高重频固体激光的窄脉冲信号进行捕捉,对积分电路的原理构成、周期窄脉冲信号采集放大电路的设计、测量误差来源及处理做了分析和讨论。以W77E58为采集电路的CPU,以FT245BM为核心构成USB接口电路,实现了窄脉冲信号的快速采集与传输,较好地解决了对多路探测器实时快速采集和向上位机传送的问题,达到了比较满意的效果。 相似文献