RESUMO
BACKGROUND: Mitochondrial Ts translation elongation factor (TSFM) is an enzyme that catalyzes exchange of guanine nucleotides. By forming a complex with mitochondrial Tu translation elongation factor (TUFM), TSFM participates in mitochondrial protein translation. We have previously reported that TUFM regulates translation of beta-site APP cleaving enzyme 1 (BACE1) via ROS (reactive oxygen species)-dependent mechanism, suggesting a potential role in amyloid precursor protein (APP) processing associated with Alzheimer's disease (AD), which led to the speculation that TSFM may regulate APP processing in a similar way to TUFM. METHODS AND RESULTS: Here, we report that in cultured cells, knockdown or overexpression TSFM did not change protein levels in BACE1 and APP. Besides, the levels of cytoplasmic ROS and mitochondrial superoxide, in addition to ATP level, cell viability and mitochondrial membrane potential were not significantly altered by TSFM knockdown in the short term. Further transcriptome analysis revealed that expression of majority of mitochondrial genes were not remarkably changed by TSFM silencing. The possibility of TSFM involved in cardiomyopathy and cancer development was uncovered using bioinformatics analysis. CONCLUSIONS: Collectively, short-term regulation of TSFM level in cultured cells does not cause a significant change in proteins involved in APP processing, levels in ROS and ATP associated with mitochondrial function. Whereas our study could contribute to comprehend certain clinical features of TSFM mutations, the roles of TSFM in cardiomyopathy and cancer development might deserve further investigation.
Assuntos
Doença de Alzheimer , Cardiomiopatias , Neoplasias , Humanos , Secretases da Proteína Precursora do Amiloide/genética , Secretases da Proteína Precursora do Amiloide/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Ácido Aspártico Endopeptidases/genética , Doença de Alzheimer/metabolismo , Mitocôndrias/genética , Mitocôndrias/metabolismo , Neoplasias/metabolismo , Cardiomiopatias/metabolismo , Fatores de Alongamento de Peptídeos/metabolismo , Trifosfato de Adenosina , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismoRESUMO
Based on the one-year observational data of volatile organic compounds ï¼VOCsï¼ in an urban area of Yuncheng in 2021ï¼ the concentrationï¼ compositionï¼ sourcesï¼ and ozone-sensitive species of VOCs in four seasons were analyzed. The results showed that the average annual concentration of VOCs was ï¼32.1 ±24.2ï¼×10-9ï¼ i.e.ï¼ at the national middle level. The seasonal concentrations of VOCs were in the order ofï¼ winter ï¼46.3×10-9ï¼> autumn ï¼35.5×10-9ï¼> spring ï¼25.6×10-9ï¼> summer ï¼21.2×10-9ï¼. Alkanes and OVOCs were the most dominant VOCs compoundsï¼ accounting for 69.0%-80.4% of TVOCs in Yuncheng. Affected by changes in source emissionsï¼ the proportion of OVOCs was higher in spring and summer ï¼41%-43%ï¼ï¼ whereas the proportion of alkanes was higher in autumn and winter ï¼42%-43%ï¼. Vehicle exhaustï¼ LPG/NGï¼ industrial productionï¼ and combustion sources were identified as the main sources of VOCs in Yuncheng. The largest contributors in the four seasons were vehicle exhaust ï¼28.5% in springï¼ï¼ secondary + combustion sources ï¼29.0% in summerï¼ï¼ LPG/NG sources ï¼30.4% in autumnï¼ï¼ and coal combustion ï¼27.3% in winterï¼. The ozone formation was located in the transitional regime in summer and in the VOC-limited regime in other seasons. Ozone production was more sensitive to alkenes ï¼isopreneï¼ ethyleneï¼ and propeneï¼ï¼ OVOCs ï¼acetaldehyde and propanalï¼ï¼ and aromatics ï¼xyleneï¼ tolueneï¼ and benzeneï¼. Winter was more sensitive to ethyleneï¼ and the other seasons were more sensitive to isoprene. The primary emission sources related to these sensitive species should be reduced to achieve the goal of air quality improvement.
RESUMO
Staufen-1 (STAU1) is a double-stranded RNA-binding protein (RBP) involved in a variety of pathological conditions. In this study, we investigated the potential role of STAU1 in Alzheimer's disease (AD), in which two hallmarks are well-established as cerebral ß-amyloid protein (Aß) deposition and Tau-centered neurofibrillary tangles. We found that STAU1 protein level was significantly increased in cells that stably express full-length APP and the brain of APP/PS1 mice, an animal model of AD. STAU1 knockdown, as opposed to overexpression, significantly decreased the protein levels of ß-amyloid converting enzyme 1 (BACE1) and Aß. We further found that STAU1 extended the half-life of the BACE1 mRNA through binding to the 3' untranslated region (3'UTR). Transcriptome analysis revealed that STAU1 enhanced the expression of growth arrest and DNA damage 45 ß (GADD45B) upstream of P38 MAPK signaling, which contributed to STAU1-induced regulation of Tau phosphorylation at Ser396 and Thr181. Together, STAU1 promoted amyloidogenesis by inhibiting BACE1 mRNA decay, and augmented Tau phosphorylation through activating GADD45B in relation to P38 MAPK. Targeting STAU1 that acts on both amyloidogenesis and tauopathy may serve as an optimistic approach for AD treatment.
Assuntos
Secretases da Proteína Precursora do Amiloide , Ácido Aspártico Endopeptidases , Proteínas de Ligação a RNA , Proteínas tau , Animais , Proteínas tau/metabolismo , Proteínas tau/genética , Proteínas de Ligação a RNA/metabolismo , Proteínas de Ligação a RNA/genética , Camundongos , Fosforilação , Secretases da Proteína Precursora do Amiloide/metabolismo , Secretases da Proteína Precursora do Amiloide/genética , Ácido Aspártico Endopeptidases/metabolismo , Ácido Aspártico Endopeptidases/genética , Humanos , Camundongos Transgênicos , Peptídeos beta-Amiloides/metabolismo , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Doença de Alzheimer/genética , Células Cultivadas , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Proteínas do Citoesqueleto/metabolismo , Proteínas do Citoesqueleto/genéticaRESUMO
Discovery of new small molecules that can activate distinct programmed cell death pathway is of significant interest as a research tool and for the development of novel therapeutics for pathological conditions such as cancer and infectious diseases. The small molecule raptinal was discovered as a pro-apoptotic compound that can rapidly trigger apoptosis by promoting the release of cytochrome c from the mitochondria and subsequently activating the intrinsic apoptotic pathway. As raptinal is very effective at inducing apoptosis in a variety of different cell types in vitro and in vivo, it has been used in many studies investigating cell death as well as the clearance of dying cells. While examining raptinal as an apoptosis inducer, we unexpectedly identified that in addition to its pro-apoptotic activities, raptinal can also inhibit the activity of caspase-activated Pannexin 1 (PANX1), a ubiquitously expressed transmembrane channel that regulates many cell death-associated processes. By implementing numerous biochemical, cell biological and electrophysiological approaches, we discovered that raptinal can simultaneously induce apoptosis and inhibit PANX1 activity. Surprisingly, raptinal was found to inhibit cleavage-activated PANX1 via a mechanism distinct to other well-described PANX1 inhibitors such as carbenoxolone and trovafloxacin. Furthermore, raptinal also interfered with PANX1-regulated apoptotic processes including the release of the 'find-me' signal ATP, the formation of apoptotic cell-derived extracellular vesicles, as well as NLRP3 inflammasome activation. Taken together, these data identify raptinal as the first compound that can simultaneously induce apoptosis and inhibit PANX1 channels. This has broad implications for the use of raptinal in cell death studies as well as in the development new PANX1 inhibitors.
Assuntos
Apoptose , Conexinas , Fluorenos , Trifosfato de Adenosina/metabolismo , Apoptose/efeitos dos fármacos , Morte Celular , Conexinas/antagonistas & inibidores , Conexinas/metabolismo , Ciclopentanos/farmacologiaRESUMO
OBJECTIVE: To explore the mechanism of electroacupunctureï¼EAï¼ in improving learning-memory ability in Alzheimer's disease ï¼ADï¼ mice from the perspective of endosomal-lysosomal system. METHODS: Male APP/PS1 transgenic mice were randomly divided into model group and EA group ï¼n=10 in each groupï¼ and 10 male C57BL/6 wild mice were taken as the normal group. EA ï¼1 Hz/50 Hz, 1 mAï¼ was applied at bilateral "Yongquan"ï¼KI1ï¼ and acupuncture was applied at "Baihui" ï¼GV20ï¼ for 15 min. The mice of the model and normal groups were subjected to restriction with the same method as those of the EA group for 15 min. The treatment was conducted once every other day for 6 weeks. The spatial learning-memory ability ï¼shown by escape latency of place navigation test and the time of crossing the target platform and total swimming distance in the target quadrant in 1 min of spatial probe test ï¼ was detected by Morris water maze test. The immunoactivity of senile plaques ï¼SPï¼ in the hippocampus tissue was detected by immunohistochemistry. The ultrastructural characters of hippocampal neurons were observed by transmission electron microscope, and the expression levels of Ras-related protein 5 ï¼Rab5ï¼, Ras-related protein 7 ï¼Rab7ï¼ and cathepsin D ï¼CTSDï¼ in the hippocampus were detected by Western blot, separately. RESULTS: Compared with the normal group, the escape latency, SP immunoactivity, and protein expression levels of Rab5, Rab7 and CTSD were significantly increased ï¼P<0.05, P<0.01ï¼, while the number of crossing the original platform and the total swimming distance in the platform quadrant were considerably reduced ï¼P<0.05ï¼ in the model group. In contrast to the model group, the EA group had a marked decrease in the escape latency, SP immunoactivity, and protein expression levels of Rab5, Rab7 and CTSD ï¼P<0.05, P<0.01ï¼, and a striking increase in the number of crossing the original platform and the swimming distance in the platform quadrant ï¼P<0.05ï¼. Results of transmission electron microscope showed an accumulation of endosome, lysosome, and endolysosomes in the hippocampal neurons in the model group, which was evidently milder in the EA group. CONCLUSION: EA of GV20 and KI1 can improve the learning-memory ability of AD mice, which may be related to its function in reducing hippocampal Aß deposition and down-regulating endosomal-lysosomal system activity.
Assuntos
Doença de Alzheimer , Eletroacupuntura , Masculino , Camundongos , Animais , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Doença de Alzheimer/genética , Doença de Alzheimer/terapia , Endossomos , Lisossomos/genética , Placa AmiloideRESUMO
TNFAIP3-interacting protein 2 (TNIP2) is known as a negative regulator of NF-κB signaling and inhibit inflammatory response and apoptosis, and is also involved in RNA metabolism. In this study, we investigated the potential role of TNIP2 in amyloidogenesis critically associated with Alzheimer's disease (AD). We found a significant decline of TNIP2 protein level in both mouse and cell model of AD. In SH-SY5Y and HEK cells that stably express human full-length APP695 (SY5Y-APP and HEK-APP), TNIP2 overexpression decreased the protein levels of ß-secretase (BACE1) and C99, as well as Aß peptides (including Aß40 and Aß42), while those of α-secretase (ADAM10) and the related C83 remained unchanged. We further found that TNIP2 promoted the degradation of BACE1 mRNA and was able to bound to the 3' untranslated region (3'UTR) with the reduced luciferase activity. These results indicated that TNIP2 effectively inhibited amyloidogenic processing by regulating the 3'UTR-associated mRNA decay of BACE1.
Assuntos
Doença de Alzheimer , Neuroblastoma , Camundongos , Humanos , Animais , Secretases da Proteína Precursora do Amiloide/genética , Secretases da Proteína Precursora do Amiloide/metabolismo , Ácido Aspártico Endopeptidases/genética , Ácido Aspártico Endopeptidases/metabolismo , Regiões 3' não Traduzidas , Peptídeos beta-Amiloides/metabolismo , Camundongos Transgênicos , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismoRESUMO
OBJECTIVE: To investigate the effect of electroacupuncture (EA) on the expression of ß-amyloid (Aß) and autophagy-related proteins in hippocampal cells of Alzheimer's disease (AD) model mice, so as to explore its underlying mechanisms. METHODS: Eighteen male APP/PS1 transgenic mice (6 months old) were randomly divided into model and EA groups, with 9 mice in each group. Nine male C57BL/6 wild-type mice of the same age were chosen as the normal group. Mice in the EA group were treated with acupuncture on "Baihui" (GV20) and EA (1 Hz/50 Hz, 1 mA) on bilateral "Yongquan" (KI1), once every other day, 20 min each time for a total of 21 times. After the interventions, the spatial learning and memory ability were observed by Morris water maze test. The autophagy-related pathological changes in hippocampus were observed by transmission electron microscopy. The expressions of microtublue associated protein 1 light chain 3 (LC3) and Aß in hippocampus were observed by immunofluorescence and the expression levels of LC3 and p62 proteins were detected by Western blot. RESULTS: Compared with the normal group, the escape latency was prolonged (P<0.01), the residence time in the original quadrant platform was shor-tened (P<0.05), the positive expressions of LC3 and Aß, the expression levels of LC3â ¡ and p62 proteins, and the ratio of LC3â ¡/LC3â proteins in hippocampus were increased (P<0.01, P<0.05) in the model group. Compared with the model group, the escape latency was shortened (P<0.05), the residence time in the original quadrant platform was prolonged (P<0.05), the positive expressions of LC3 and Aß, the expression levels of LC3â ¡ and p62 proteins, and the ratio of LC3â ¡/LC3â proteins in hippocampus were decreased (P<0.05) in the EA group. The transmission electron microscopy showed that the structure of neurons was normal in the normal group, a large number of autolysosomes and autophagosomes existed in hip-pocampal nerve cells in the model group, and only a small number of autophagosomes were observed in the EA group. CONCLUSION: EA can reduce the expression levels of autophagy-related proteins LC3 and p62 in APP/PS1 transgenic mice, improve the hip-pocampal autophagy state, reduce intracellular Aß aggregation, and thus improve the learning and memory ability.
Assuntos
Doença de Alzheimer , Eletroacupuntura , Camundongos , Masculino , Animais , Doença de Alzheimer/genética , Doença de Alzheimer/terapia , Peptídeos beta-Amiloides/genética , Peptídeos beta-Amiloides/metabolismo , Proteínas Relacionadas à Autofagia/metabolismo , Camundongos Endogâmicos C57BL , Hipocampo/metabolismo , Camundongos Transgênicos , Aprendizagem EspacialRESUMO
In this study, the spatial distribution patterns of individuals with different diameter classes of dominant shrub Lonicera fragrantissima var. lancifolia and the intraspecific and interspecific relationships were analyzed in Qinling Huangguan Plot. The results showed that the diameter class structure of L. fragrantissima var. lancifolia showed a pyramid shape, with a wide bottom and a narrow top. The number of small-diameter class individuals was the largest, showing a good state of renewal and a stable growth, which was conducive to community renewal and succession. Based on Ripley's K function, using univariate and bivariate paired correlation functions, under complete spatial randomness model, heterogeneous Poisson model and antecedent condition model, all individual of the species and their diameter-dividing classes were mainly aggregated, and the aggregation degree decreased with the increases of research scale, and gradually tended to random distribution. Affected by habitat heterogeneity, diffusion restriction and negative density dependence, there was a positive correlation among different intraspecific dia-meter classes, and also a certain degree of no correlation, but without negative correlation. The interspecific relationship was complex. All types of association (no, positive and negative) were observed, but negative association and no association were dominated.
Assuntos
Florestas , Lonicera , China , Ecossistema , Humanos , ÁrvoresRESUMO
To explore the spatial distribution and intraspecific correlation of Quercus aliena var. acutiserrata, a domi-nant tree species in a 25 hm2 plot of warm temperate deciduous broadleaved forest in Qinling Mountains, the pair-correlation function g(r) was used to study the spatial pattern and intraspecific association. The results showed that the diameter class structure of Q. aliena var. acutiserrata was bimodal, with a large proportion of young trees (1 cm≤DBHï¼5 cm), indicating an increase population structure with good capability of regeneration. The abundance of middle trees (15 cm≤DBHï¼25 cm) was slightly more than that of big trees (25 cm≤DBHï¼35 cm) and old trees (DBH≥35 cm), but far less than that of young trees and small trees. The spatial distribution of Q. aliena var. acuteserrata was obviously altitude dependent, which mainly distributed in the middle and high altitude areas. Results of complete spatial randomness (CSR) model analysis showed that young trees, small trees, adult trees, big trees, and old trees were aggregated in the large scale (ï¼60 m). Heterogeneous Poisson (HP) model was used to eliminate habitat heterogeneity. The results of HP model showed that the individual aggregation degree of each diameter class decreased, indicating that the distribution was affected by habitat heterogeneity. At the small scale (ï¼40 m), spatial correlation was positively correlated between individuals with small diameter gap, whereas the spatial correlation was negative correlation and no correlation between individuals with large diameter gap. At large scale (>40 m), the spatial correlation was positively correlated between large-diameter individuals, but negatively correlated and unrelated between saplings and other diameter individuals. Our results indicated that biological cha-racteristics of Q. aliena var. acutiserrata and habitat heterogeneity were important drivers for the formation of population spatial pattern.