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931.
Mi Deng Pei-Chao Chen Sisi Xie Junqiong Zhao Lili Gong Jinping Liu Lan Zhang Shuming Sun Jiao Liu Haili Ma Surinder K. Batra David Wan-Cheng Li 《生物化学与生物物理学报:疾病的分子基础》2010,1802(7-8):621-631
The small heat shock protein αA-crystallin is a structural protein in the ocular lens. In addition, recent studies have also revealed that it is a molecular chaperone, an autokinase and a strong anti-apoptotic regulator. Besides its lenticular distribution, a previous study demonstrates that a detectable level of αA-crystallin is found in other tissues including thymus and spleen. In the present study, we have re-examined the distribution of αA-crystallin in various normal human and mouse tissues and found that the normal pancreas expresses a moderate level of αA-crystallin. Moreover, αA-crystallin is found significantly downregulated in 60 cases of pancreatic carcinoma of different types than it is in 11 normal human pancreas samples. In addition, we demonstrate that αA-crystallin can enhance the activity of the activating protein-1 (AP-1) through modulating the function of the MAP kinase, and also upregulates components of TGFβ pathway. Finally, expression of αA-crystallin in a pancreatic cancer cell line, MiaPaCa, results in retarded cell migration. Together, these results suggest that αA-crystallin seems to negatively regulate pancreatic carcinogenesis. 相似文献
932.
Yongqing Hou Lei Wang Dan Yi Binying Ding Zhenguo Yang Jiao Li Xing Chen Yinsheng Qiu Guoyao Wu 《Amino acids》2013,45(3):513-522
This study determined whether N-acetylcysteine (NAC) could affect intestinal redox status, proinflammatory cytokines, epidermal growth factor (EGF), EGF receptor (EGFR), Toll-like receptor-4 (TLR4), and aquaporin-8 in a lipopolysaccharide (LPS)-challenged piglet model. Eighteen piglets (35-day-old) were randomly allocated into one of the three treatments (control, LPS and NAC). The control and LPS groups were fed a basal diet, and the NAC group received the basal diet +500 mg/kg NAC. On days 10, 13, and 20 of the trial, the LPS- and NAC-treated piglets received intraperitoneal administration of LPS (100 μg/kg BW), whereas the control group received the same volume of saline. On days 10 and 20, venous blood samples were obtained at 3 h post LPS or saline injection. On day 21 of the trial, piglets were killed to obtain the intestinal mucosa for analysis. Compared with the control group, LPS challenge reduced (P < 0.05) the activities of superoxide dismutase, catalase, and glutathione peroxidase in jejunal mucosae, while increasing (P < 0.05) the concentrations of malondialdehyde, H2O2, O2 ·? and the ratio of oxidized to reduced glutathione in jejunal mucosae, and concentrations of TNF-α, cortisol, interleukin-6, and prostaglandin E2 in both plasma and intestinal mucosae. These adverse effects of LPS were attenuated (P < 0.05) by NAC supplementation. Moreover, NAC prevented LPS-induced increases in abundances of intestinal HSP70 and NF-κB p65 proteins and TLR4 mRNA. NAC supplementation enhanced plasma EGF concentration and intestinal EGFR mRNA levels. Collectively, these results indicate that dietary NAC supplementation alleviates LPS-induced intestinal inflammation via regulating redox, EGF, and TLR4 signaling. 相似文献
933.
934.
Differential expression of ubiquitin was previously reported between Plutella xylostella strains that are resistant or susceptible to the pesticide deltamethrin (DM). This finding hinted at the potential involvement of ubiquitin in deltamethrin resistance, a theory that demanded further testing. Real-time PCR analyses revealed that one of the ubiquitin genes, UBL40, was overexpressed in the deltamethrin-resistant strain during the fourth instar. To investigate the functional relationship between this gene and deltamethrin resistance, RNA interference (RNAi) and cell transfection were utilised. UBL40 knockdown was observed to significantly reduce the level of resistance in RNAi-treated larvae after 48 h. Conversely, overexpression of UBL40 in Drosophila Kc cells conferred a degree of protection against deltamethrin. These results represent the first evidence that UBL40 plays a role in the regulation of deltamethrin resistance in P. xylostella. 相似文献
935.
杜氏盐藻细胞质膜氧化还原系统与K^+吸收 总被引:3,自引:0,他引:3
杜氏盐藻(Dunaliella salina)细胞表面存在氧化NADH 与还原Fe(CN)3-6 的氧化还原系统(redoxsystem )。该系统在氧化NADH 时,抑制K+ 的吸收,在还原Fe(CN)3-6 时, 促进K+ 的吸收,当NADH 同时存在时, 促进效应最显著, 高达735% 。外源NADH 促进藻细胞的氧吸收达165% ,而使胞质pH 下降; 当NADH 存在时, Fe(CN)3-6 被快速地还原, 同时藻细胞膜外酸化程度增加。质膜H+ -ATPase和氧化还原系统的典型抑制剂都不同程度地抑制K+ 吸收; 并且钒酸盐对K+ 吸收的抑制可以被加入NADH 和Fe(CN)3-6 而部分恢复, 表明质膜H+ -ATPase和氧化还原系统共同参与了细胞K+ 的吸收过程 相似文献
936.
937.
Liang Fang Wen Wang Guipeng Li Li Zhang Jun Li Diwen Gan Jiao Yang Yisen Tang Zewen Ding Min Zhang Wenhao Zhang Daqi Deng Zhengyu Song Qionghua Zhu Huanhuan Cui Yuhui Hu Wei Chen 《Molecular systems biology》2020,16(11)
Cellular RNA is decorated with over 170 types of chemical modifications. Many modifications in mRNA, including m6A and m5C, have been associated with critical cellular functions under physiological and/or pathological conditions. To understand the biological functions of these modifications, it is vital to identify the regulators that modulate the modification rate. However, a high‐throughput method for unbiased screening of these regulators is so far lacking. Here, we report such a method combining pooled CRISPR screen and reporters with RNA modification readout, termed CRISPR integrated gRNA and reporter sequencing (CIGAR‐seq). Using CIGAR‐seq, we discovered NSUN6 as a novel mRNA m5C methyltransferase. Subsequent mRNA bisulfite sequencing in HAP1 cells without or with NSUN6 and/or NSUN2 knockout showed that NSUN6 and NSUN2 worked on non‐overlapping subsets of mRNA m5C sites and together contributed to almost all the m5C modification in mRNA. Finally, using m1A as an example, we demonstrated that CIGAR‐seq can be easily adapted for identifying regulators of other mRNA modification. 相似文献
938.
M M Cleland K L Norris M Karbowski C Wang D-F Suen S Jiao N M George X Luo Z Li R J Youle 《Cell death and differentiation》2011,18(2):235-247
The regulation of both mitochondrial dynamics and apoptosis is key for maintaining the health of a cell. Bcl-2 family proteins, central in apoptosis regulation, also have roles in the maintenance of the mitochondrial network. Here we report that Bax and Bak participate in the regulation of mitochondrial fusion in mouse embryonic fibroblasts, primary mouse neurons and human colon carcinoma cells. To assess how Bcl-2 family members may regulate mitochondrial morphogenesis, we determined the binding of a series of chimeras between Bcl-xL and Bax to the mitofusins, mitofusin 1 (Mfn1) and mitofusin 2 (Mfn2). One chimera (containing helix 5 (H5) of Bax replacing H5 of Bcl-xL (Bcl-xL/Bax H5)) co-immunoprecipitated with Mfn1 and Mfn2 significantly better than either wild-type Bax or Bcl-xL. Expression of Bcl-xL/Bax H5 in cells reduced the mobility of Mfn1 and Mfn2 and colocalized with ectopic Mfn1 and Mfn2, as well as endogenous Mfn2 to a greater extent than wild-type Bax. Ultimately, Bcl-xL/Bax H5 induced substantial mitochondrial fragmentation in healthy cells. Therefore, we propose that Bcl-xL/Bax H5 disturbs mitochondrial morphology by binding and inhibiting Mfn1 and Mfn2 activity, supporting the hypothesis that Bcl-2 family members have the capacity to regulate mitochondrial morphology through binding to the mitofusins in healthy cells. 相似文献
939.
HS1-associated protein X-1 (Hax-1) is an intracellular protein with anti-apoptotic properties that, in addition to suppressing
cell death by inhibiting the activation of initiator caspase-9 and death caspase-3, is involved in an increasing number of
signaling cascades. However, its expression and function in the central nervous system lesion are still unclear. In this study,
we performed a traumatic brain injury (TBI) model in adult rats and investigated the dynamic changes of Hax-1 expression in
the brain cortex. Western blot and immunohistochemistry analysis revealed that Hax-1 was present in normal brain. It gradually
increased, reached a peak at day 3 after TBI, and then declined during the following days. Double immunofluorescence staining
showed that Hax-1 immunoreactivity (IR) was found in neurons, but not astrocytes and microglia. Moreover, the 3rd day post
injury was the apoptotic peak implied by the alteration of caspase-3, Bcl-2 and TUNEL. All these results suggested that Hax-1
may be involved in the pathophysiology of TBI and further research is needed to have a good understanding of its function
and mechanism. 相似文献
940.
Pengshan Zhao Fei Liu Miao Ma Jiao Gong Qiujun Wang Pengfei Jia Guochang Zheng Heng Liu 《Molecular Biology》2011,45(5):785-796
Previous studies have shown that the late embryogenesis abundant (LEA) group 3 proteins significantly respond to changes in environmental conditions. However, reports that demonstrate their biological role, especially in Arabidopsis, are notably limited. This study examines the functional roles of the Arabidopsis LEA group 3 proteins AtLEA3-3 and AtLEA3-4 in abiotic stress and ABA treatments. Expression of AtLEA3-3 and AtLEA3-4 is upregulated by ABA, high salinity, and osmotic stress. Results on the ectopic expression of AtLEA3-3 and AtLEA3-4 in E. coli suggest that both proteins play important roles in resistance to cold stress. Overexpression of AtLEA3-3 in Arabidopsis (AtLEA3-3-OE) confers salt and osmotic stress tolerance that is characterized during germination and early seedling establishment. However, AtLEA3-3-OE lines show sensitivity to ABA treatment during early seedling development. These results suggest that accumulation of AtLEA3-3 mRNA and/or proteins may help heterologous ABA reinitiate second dormancy during seedling establishment. Analysis of yellow fluorescent fusion proteins localization shows that AtLEA3-3 and AtLEA3-4 are mainly distributed in the ER and that AtLEA3-3 also localizes in the nucleus, and in response to salt, mannitol, cold, or BFA treatments, the localization of AtLEA3-3 and AtLEA3-4 is altered and becomes more condensed. Protein translocalization may be a positive and effective strategy for responding to abiotic stresses. Taken together, these results suggest that AtLEA3-3 has an important function during seed germination and seedling development of Arabidopsis under abiotic stress conditions. 相似文献