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951.
952.
Hua Jin Xun Huang Yong Chen Hongxia Zhao Hongyan Ye Feicheng Huang Xiaobo Xing Jiye Cai 《Applied microbiology and biotechnology》2010,88(3):761-770
The photodynamic antimicrobial chemotherapy as a promising approach for efficiently killing pathogenic microbes is attracting
increasing interest. In this study, the cytotoxic and phototoxic effects of hematoporphyrin monomethyl ether (HMME) on the
Gram-positive and Gram-negative bacteria were investigated. The cell viability was assessed by colony-forming unit method,
and the results indicated that there was no significant cytotoxicity but high phototoxicity in the examined concentrations.
Notably, the Gram-positive bacteria were more sensitive to HMME in phototoxicity. Simultaneously, an atomic force microscope
(AFM) was used to detect the changes in morphological and nanomechanical properties of bacteria before and after HMME treatment.
AFM images indicate that upon photoinactivation, the bacterial surface changed from a smooth, homogeneous architecture to
a heterogenous, crackled morphology. The force spectroscopy measurements reveal that the cell wall became less rigid and the
Young’s modulus decreased about 50%, whereas the tip-cell-surface adhesion forces increased significantly compared to those
of native cells. It was speculated that the photodynamic effects of HMME induced the changes in the chemical composition of
the outer membrane and exposure of some proteins inside the envelope. AFM can be utilized as a powerful and sensitive method
for studying the interaction between bacteria and drugs. 相似文献
953.
Salvia miltiorrhiza Bunge (Lamiaceae) root, generally called Danshen, is an important herb in Chinese medicine widely used for treatment of cardiovascular
diseases. Diterpenoid tanshinons are major bioactive constituents of Danshen with notable pharmacological activities and the
potential as new drug candidates against some important human diseases. The importance of Danshen for traditional and modern
medicines has motivated the research interest over two decades in the biosynthesis and biotechnological production of tanshinones.
Although diterpenes in plants are presumably derived from the non-mevalonate (MVA) pathway, tanshinone biosynthesis in S. miltiorrhiza may also depend on the MVA pathway based on some key enzymes and genes detected in the early steps of these pathways. Plant
tissue cultures are the major biotechnological processes for rapid production of tanshinones and other bioactive compounds
in the herb. Various in vitro cultures of S. miltiorrhiza have been established, including cell suspension, adventitious root, and hairy root cultures, which can accumulate the major
tanshinones as in the plant roots. Tanshinone production in cell and hairy root cultures has been dramatically enhanced with
various strategies, including medium optimization, elicitor stimulation, and nutrient feeding operations. This review will
summarize the above developments and also provide our views on future trends. 相似文献
954.
Lee HS Chang JH Ku SK 《Folia histochemica et cytobiologica / Polish Academy of Sciences, Polish Histochemical and Cytochemical Society》2010,48(3):387-393
The regional distribution and frequency of the pancreatic endocrine cells in the ddN mouse were studied using specific antisera against insulin, glucagon, somatostatin and human pancreatic polypeptide (hPP). In the pancreatic islets, most of insulin-immunoreactive (IR) cells were located in the central region, and glucagon-, somatostatin and hPP-IR cells were located in the peripheral region regardless of the lobe. In the splenic part, glucagon-IR cells were also located in the central regions, and more numerous somatostatin-IR cells were detected in the central regions as compared with the duo-denal part. hPP-IR cells were restricted to the peripheral regions in both lobes but more numerous cells were detected in the duodenal portion. In the exocrine parenchyma of the splenic lobe, only insulin- and glucagon-IR cells were detected but all four kinds of IR cells were observed in the duodenal portion. In addition, insulin and hPP-IR cells were also demonstrated in the pancreatic duct regions. In conclusion, some strain-dependent characteristic distributional patterns of pancreatic endocrine cells were found in the ddN mouse with somewhat different distributional patterns between the two pancreatic lobes. 相似文献
955.
Joo‐Yong Lee Waixing Tang Esther Wong Ya‐Sheng Gao Udai B Pandey Susmita Kaushik Emily Tresse Jianrong Lu J Paul Taylor Ana Maria Cuervo Tso‐Pang Yao 《The EMBO journal》2010,29(5):969-980
Autophagy is primarily considered a non‐selective degradation process induced by starvation. Nutrient‐independent basal autophagy, in contrast, imposes intracellular QC by selective disposal of aberrant protein aggregates and damaged organelles, a process critical for suppressing neurodegenerative diseases. The molecular mechanism that distinguishes these two fundamental autophagic responses, however, remains mysterious. Here, we identify the ubiquitin‐binding deacetylase, histone deacetylase‐6 (HDAC6), as a central component of basal autophagy that targets protein aggregates and damaged mitochondria. Surprisingly, HDAC6 is not required for autophagy activation; rather, it controls the fusion of autophagosomes to lysosomes. HDAC6 promotes autophagy by recruiting a cortactin‐dependent, actin‐remodelling machinery, which in turn assembles an F‐actin network that stimulates autophagosome–lysosome fusion and substrate degradation. Indeed, HDAC6 deficiency leads to autophagosome maturation failure, protein aggregate build‐up, and neurodegeneration. Remarkably, HDAC6 and F‐actin assembly are completely dispensable for starvation‐induced autophagy, uncovering the fundamental difference of these autophagic modes. Our study identifies HDAC6 and the actin cytoskeleton as critical components that define QC autophagy and uncovers a novel regulation of autophagy at the level of autophagosome–lysosome fusion. 相似文献
956.
Choong Hyun Lee Jung Hoon Choi Ki-Yeon Yoo Ok Kyu Park In Koo Hwang Sang Guan You Boo-Yong Lee Il-Jun Kang Moo-Ho Won 《Cellular and molecular neurobiology》2010,30(2):255-263
Melatonin exerts many physiological functions via its G protein-coupled receptors. In the present study, we investigated age-related
changes in MT2 melatonin receptor immunoreactivity and its levels in the gerbil hippocampus during normal aging. In the postnatal
month 1 (PM 1) group, MT2 immunoreaction was well observed in neurons in all subregions of the gerbil hippocampus. In the
PM 3 and 6 groups, MT2 immunoreactivity in neurons was decreased compared to that in the PM 1 group. Thereafter, MT2 immunoreactivity
in neurons was increased. In the PM 18 and 24 groups, MT2 immunoreactivity in neurons was strong in all subregions of the
gerbil hippocampus. In addition, the number of MT2 immunoreactive cells was lowest at PM 3 and highest at PM 24. From western
blot analysis, age-dependent change pattern in MT2 level in the gerbil hippocampus was similar to the immunohistochemical
result. These results indicate that MT2 immunoreactivity and levels are altered in the gerbil hippocampus during normal aging;
lowest at young adult stage and highest at aged stage. 相似文献
957.
The inositol 1,4,5-trisphosphate (IP3)-mediated intracellular Ca2+ releases in secretory cells play vital roles in controlling not only the intracellular Ca2+ concentrations but also the Ca2+-dependent exocytotic processes. Of intracellular organelles that release Ca2+ in response to IP3, secretory granules stand out as the most prominent organelle and are responsible for the majority of IP3-dependent Ca2+ releases in the cytoplasm of chromaffin cells. Bovine chromaffin granules were the first granules that demonstrated the IP3-mediated Ca2+ release as well as the presence of the IP3 receptor (IP3R) in granule membranes. Secretory granules contain all three (type 1, 2, and 3) IP3R isoforms, and 58–69% of total cellular IP3R isoforms are expressed in bovine chromaffin granules. Moreover, secretory granules contain large amounts (2–4 mM) of chromogranins
and secretogranins; chromogranins A and B, and secretogranin II being the major species. Chromogranins A and B, and secretogranin
II are high-capacity, low-affinity Ca2+ binding proteins, binding 30–93 mol of Ca2+/mol of protein with dissociation constants of 1.5–4.0 mM. Due to this high Ca2+ storage properties of chromogranins secretory granules contain ~40 mM Ca2+. Furthermore, chromogranins A and B directly interact with the IP3Rs and modulate the IP3R/Ca2+ channels, i.e., increasing the open probability and the mean open time of the channels 8- to 16-fold and 9- to 42-fold, respectively.
Coupled chromogranins change the IP3R/Ca2+ channels to a more ordered, release-ready state, whereby making the IP3R/Ca2+ channels significantly more sensitive to IP3. 相似文献
958.
Xuanwen Li Li Xiong Chunliang Xie Jia Cao Huobao Deng Yong Lin Rui Cao Jianglin Li Ping Chen Songping Liang 《Molecular and cellular biochemistry》2010,344(1-2):137-150
Liver regeneration is an angiogenesis-associated phenomenon. To identify key plasma membrane (PM) proteins of endothelial cells involved in the initiation of angiogenesis during liver regeneration, the PM of liver sinusoidal endothelial cells (LSEC) at 72 h after partial hepatectomy was enriched by an established in vivo membrane density perturbation method. The differentially expressed membrane proteins compared to those from sham operation were quantified using an improved two-dimensional 16-BAC/SDS-PAGE and identified by LC-MS/MS. Several proteins were further confirmed by cICAT labeling quantitative strategy. A total of 47 proteins were identified including known and novel proteins involved in angiogenesis or liver regeneration, such as inducible nitric oxide synthase, type IV collagen, and integrin beta3. Our results indicated that the combination of the membrane density perturbation strategy and the improved two-dimensional electrophoresis (2-DE) method are useful for investigating the endothelial dysfunctions in vivo. 相似文献
959.
Fenofibrate but not fenofibric acid inhibits 11beta-hydroxysteroid dehydrogenase 1 in C2C12 myotubes
Chi Hyun Kim Ravirala Ramu Jin Hee Ahn Myung Ae Bae Young Sik Cho 《Molecular and cellular biochemistry》2010,333(1-2):91-98
Microtubules (MTs) play an important role in cell division, and their functions are regulated by a set of microtubule-associated proteins (MAPs). Tubulin polymerization promoting protein family member 3 (TPPP3), also known as p20, is a new member of the tubulin polymerization promoting protein (TPPP) family. Previous studies have demonstrated that TPPP3 specifically binds to MTs and positively regulates MTs assembly, which leads to significant ultrastructural alterations of the MTs network. However, the physiological function of TPPP3 is still largely unknown. In the present study, we showed that knockdown of endogenous TPPP3 by RNA interference (RNAi) suppressed cell proliferation and induced cell cycle arrest in HeLa cells. Furthermore, we showed that the depletion of TPPP3 caused mitotic abnormalities, such as the formation of multipolar spindles and chromosome segregation errors, which lead to apoptosis in HeLa cells. Our study suggested that TPPP3 played a crucial role in cell mitosis by regulating centrosomes amplification and/or spindles translocation processes. 相似文献
960.
Yong Gao Yun Zhao Tingting Li Yang Liu Caixia Ren Maolin Wang 《Molecular biology reports》2010,37(2):1037-1044
F-box protein family is characterized by an F-box motif that has been shown to be critical for the controlled degradation
of regulatory proteins. In plant, F-box protein plays an important role in signal pathways and involved in various signal
transduction systems. A full-length cDNA encoding a putative F-box protein, designated as BnSLY1, was isolated from Brassica napus. The full-length cDNA of BnSLY1 was 809 bp containing a 438 bp open reading frame encoding a precursor protein of 138 amino acid residues. Comparative and
bioinformatic analyses revealed that BnSLY1 showed high degree of homology with F-box proteins from other plant species and contained F-box, GGF and LSL conserved motifs.
The expression of BnSLY1 under exogenous gibberellins acid-3 (GA3), abscisic acid (ABA) and GA biosynthetic inhibitor paclobutrazol (PAC) was analyzed using real-time PCR. The results showed
that the expression of BnSLY1 was down-regulated after GA3 treatment and prominently induced by ABA in the low concentrations. Moreover, BnSLY1 was also induction in the high concentrations of PAC. These results suggest that the expression of BnSLY1 was regulated by the exogenous GA3, ABA and PAC and may be related to endogenous level of GA in B. napus. 相似文献