Genome-wide analysis of the Tritipyrum NAC gene family and the response of TtNAC477 in salt tolerance.

NAC transcription factors are widely distributed in the plant kingdom and play an important role in the response to various abiotic stresses in plant species. Tritipyrum, an octoploid derived from hybridization of Triticum aestivum (AABBDD) and Thinopyrum elongatum (EE), is an important genetic resource for integrating the desirable traits of Th. elongatum into wheat. In this study, we investigated the tissue distribution and expression of Tritipyrum NAC genes in the whole genomes of T. aestivum and Th. elongatum after obtaining their complete genome sequences. Based on phylogenetic relationships, conserved motifs, gene synthesis, evolutionary analysis, and expression patterns, we identified and characterized 732 Tritipyrum NAC genes. These genes were divided into six main groups (A, B, C, D, E, and G) based on phylogenetic relationships and evolutionary studies, with members of these groups sharing the same motif composition. The 732 TtNAC genes are widely distributed across 28 chromosomes and include 110 duplicated genes. Gene synthesis analysis indicated that the NAC gene family may have a common ancestor. Transcriptome data and quantitative polymerase chain reaction (qPCR) expression profiles showed 68 TtNAC genes to be highly expressed in response to various salt stress and recovery treatments. Tel3E01T644900 (TtNAC477) was particularly sensitive to salt stress and belongs to the same clade as the salt tolerance genes ANAC019 and ANAC055 in Arabidopsis. Pearson correlation analysis identified 751 genes that correlated positively with expression of TtNAC477, and these genes are enriched in metabolic activities, cellular processes, stimulus responses, and biological regulation. TtNAC477 was found to be highly expressed in roots, stems, and leaves in response to salt stress, as confirmed by real-time PCR. These findings suggest that TtNAC477 is associated with salt tolerance in plants and might serve as a valuable exogenous gene for enhancing salt tolerance in wheat.

Genome-wide analysis of the AP2/ERF gene family in Tritipyrum and the response of TtERF_B2-50 in salt-tolerance.

The AP2/ERF transcription factor is widely distributed across the plant kingdom and plays a crucial role in various abiotic stress responses in plants. Tritipyrum, an octoploid resulting from an intergeneric cross between Triticum aestivum (AABBDD) and Thinopyrum elongatum (EE), is a valuable source of germplasm for incorporating superior traits of Th. elongatum into T. aestivum. With the recent availability of whole -genome sequences for T. aestivum and Th. elongatum, we explored the organization and expression profiling of Tritipyrum AP2/ERF genes across the entire genome. Our investigation identified 543 Tritipyrum AP2/ERF genes, which evolutionary analysis categorized into four major groups (AP2, DREB, ERF, and RAV), whose members share a conserved motif composition. These 543 TtAP2/ERF genes were distributed throughout 28 chromosomes, with 132 duplications. Synteny analysis suggests that the AP2/ERF gene family may have a common ancestor. Transcriptome data and Real-Time PCR expression profiles revealed 43 TtAP2/ERF genes with high expression levels in response to various salt stressors and recovery regimens. Tel2E01T236300 (TtERF_B2-50) was particularly salt stress-sensitive and evolutionarily related to the salt-tolerant gene AtERF7 in A. thaliana. Pearson correlation analysis identified 689 genes positively correlated (R > 0.9) with TtERF_B2-50 expression, enriched in metabolic activities, cellular processes, stimulus response, and biological regulation. Real-time PCR showed that TtERF_B2-50 was highly expressed in roots, stems, and leaves under salt stress. These findings suggest that TtERF_B2-50 may be associated with salt stress tolerance and may serve as a valuable foreign gene for enhancing salt tolerance in wheat.

Variation of soil physicochemical properties of different vegetation restoration types on subtropical karst area in southern China.

To carry out differentiated ecological restoration activities and formulate appropriate environmental conservation strategies for karst regions, it is essential to investigate the impact of ecological restoration and forest management strategy differences on soil properties. The karst region in Xiangxi, Hunan province, China was selected as the study site. Here, we determined soil physical and chemical differences in soil profiles of karst areas with ecological restoration activities. The results showed that (1) the soil properties showed a significant difference between the restoration vegetation and uncultivated land, especially in soil physical properties. The soil moisture conversion coefficient (83.0%) and soil bulk density (1.37g/cm3) of Liriodendron chinense (Hemsl.) Sarg reached the highest value among 12 vegetations. 2) The topsoil was more sensitive to ecological restoration. Soil physical properties in the topsoil samples from the forest management areas were significantly higher than uncultivated lands (P < 0.05). (3) Redundancy analysis showed that the soil chemical content differed significantly among the types of forest vegetation restoration and different soil layers. Among the nutrients analysis, Mg, Zn and K were the main factors affecting soil properties in the rocky desertification areas. Therefore, our results recommend planting the broadleaved deciduous forest as the preferred forest among three different forest types to enhance soil fertility and water conservation functions, especially in subtropical karst areas ecosystems, which provided for making scientific forest restoration management in the karst region.

Rickettsia sp. and Anaplasma spp. in Haemaphysalis longicornis from Shandong province of China, with evidence of a novel species "Candidatus Anaplasma Shandongensis".

Haemaphysalis longicornis is one of the most dominant and widespread tick species in China. This species mainly infests wild animals and occasionally attacks humans, and has been associated with the transmission of a variety of zoonotic pathogens including spotted fever group Rickettsia (SFGR), severe fever with thrombocytopenia syndrome virus (SFTSV), Anaplasma phagocytophilum, Babesia spp. and Theileria spp.. Although there are increasing reports of various pathogens associated with H. longicornis, some neglected pathogens in certain areas still need to be studied. In this study, a total of 171 H. longicornis ticks were collected from goats in three locations of Shandong Province, Eastern China (Zibo, Linyi, and Qingdao cities), and subsequently screened for the presence of Rickettsia, Anaplasma, and Ehrlichia bacteria. A total of four bacterial species were identified and characterized. "Candidatus Rickettsia jingxinensis" was detected in one tick specimen from Zibo city. Of 98 ticks from Linyi city, 63.27% (62/98) were tested positive for Anaplasma capra and 5.10% (5/98) were positive for Anaplasma bovis. Interestingly, a novel Anaplasma species was detected and characterized in one tick specimen from Zibo and one other from Linyi, respectively. Genetic and phylogenetic analysis based on the 16S, gltA, groEL, and msp4 genes indicated that it was divergent from all known Anaplasma species but mostly related to A. phagocytophilum and "Cadidatus Anaplasma boleense". Based on where it was first detected, we named it "Candidatus Anaplasma shandongensis".

Diversity of Rickettsiales in Rhipicephalus microplus Ticks Collected in Domestic Ruminants in Guizhou Province, China.

Rhipicephalus microplus ticks are vectors for multiple pathogens infecting animals and humans. Although the medical importance of R. microplus has been well-recognized and studied in most areas of China, the occurrence of tick-borne Rickettsiales has seldom been investigated in Guizhou Province, Southwest China. In this study, we collected 276 R. microplus ticks from cattle (209 ticks) and goats (67 ticks) in three locations of Guizhou Province. The Rickettsia, Anaplasma, and Ehrlichia were detected by targeting the 16S rRNA gene and were further characterized by amplifying the key genes. One Rickettsia (Ca. Rickettsia jingxinensis), three Ehrlichia (E. canis, E. minasensis, Ehrlichia sp.), and four Anaplasma (A. capra, A. ovis, A. marginale, Ca. Anaplasma boleense) species were detected, and their gltA and groEL genes were recovered. Candidatus Rickettsia jingxinensis, a spotted fever group of Rickettsia, was detected in a high proportion of the tested ticks (88.89%, 100%, and 100% in ticks from the three locations, respectively), suggesting the possibility that animals may be exposed to this type of Rickettsia. All the 16S, gltA, groEL, and ompA sequences of these strains are 100% identical to strains reported in Ngawa, Sichuan Province. E. minasensis, A. marginale, and Candidatus Anaplasma boleense are known to infect livestock such as cattle. The potential effects on local husbandry should be considered. Notably, E. canis, A. ovis, and A. capra have been reported to infect humans. The relatively high positive rates in Qianxinan (20.99%, 9.88%, and 4.94%, respectively) may indicate the potential risk to local populations. Furthermore, the genetic analysis indicated that the E. minasensis strains in this study may represent a variant or recombinant. Our results indicated the extensive diversity of Rickettsiales in R. microplus ticks from Guizhou Province. The possible occurrence of rickettsiosis, ehrlichiosis, and anaplasmosis in humans and domestic animals in this area should be further considered and investigated.

Genome-wide identification, phylogenetic analysis, and expression profiles of trihelix transcription factor family genes in quinoa (Chenopodium quinoa Willd.) under abiotic stress conditions.

BACKGROUND: The trihelix family of transcription factors plays essential roles in the growth, development, and abiotic stress response of plants. Although several studies have been performed on the trihelix gene family in several dicots and monocots, this gene family is yet to be studied in Chenopodium quinoa (quinoa). RESULTS: In this study, 47 C. quinoa trihelix (CqTH) genes were in the quinoa genome. Phylogenetic analysis of the CqTH and trihelix genes from Arabidopsis thaliana and Beta vulgaris revealed that the genes were clustered into five subfamilies: SIP1, GTγ, GT1, GT2, and SH4. Additionally, synteny analysis revealed that the CqTH genes were located on 17 chromosomes, with the exception of chromosomes 8 and 11, and 23 pairs of segmental duplication genes were detected. Furthermore, expression patterns of 10 CqTH genes in different plant tissues and at different developmental stages under abiotic stress and phytohormone treatment were examined. Among the 10 genes, CqTH02, CqTH25, CqTH18, CqTH19, CqTH25, CqTH31, and CqTH36, were highly expressed in unripe achenes 21 d after flowering and in mature achenes compared with other plant tissues. Notably, the 10 CqTH genes were upregulated in UV-treated leaves, whereas CqTH36 was consistently upregulated in the leaves under all abiotic stress conditions. CONCLUSIONS: The findings of this study suggest that gene duplication could be a major driver of trihelix gene evolution in quinoa. These findings could serve as a basis for future studies on the roles of CqTH transcription factors and present potential genetic markers for breeding stress-resistant and high-yielding quinoa varieties.

Soil water hydraulic redistribution in a subtropical monsoon evergreen forest.

Hydraulic redistribution (HR), which is the passive movement of water through plant roots from wet to dry soil due to the water gradient, is important for plant physiology and ecohydrological processes. However, our poor knowledge on HR in the humid monsoon climate zone hampers the understanding of the interactions between vegetation and soil water during frequent droughts in evergreen forests. Thus, 5 years (2011-2015) of data, including meteorological parameters and soil moisture content at depths of 10, 30, 50, and 100 cm in soil profiles, were compared at one evergreen broad-leaved forest and at one clear-cutting forest site in south China. Analyses of soil moisture dynamics show that HR was frequently triggered within the depth of 30 cm at the evergreen broad-leaved forest, while (if any) was less visible at the clear-cutting forest site. The daily averaged magnitude of redistributed soil water reached the maximum of 0.81 mm/d. The HR mainly occurred during the monsoon dry season (i.e., from October to March of the following year), possibly indicating a different cause, i.e., asynchronous variations in rainfall and plant water use shape the seasonal patterns of soil water HR, compared to other humid zones. During the study period when HR occurred, the average daily HR in the soil profiles replenished approximately 34-50% of the water consumption in the 0-30 cm soil layer. The simulation results of a distributed hydrology-soil-vegetation model incorporating a HR scheme indicate that evapotranspiration enhanced during drought periods when HR occurred. In the future climate change context, comprehensive investigations on the water fluxes in the atmosphere-vegetation-soil continuum are needed to fully understand the effects of HR on the physiological responses of plants and on the water cycle.

Response of soil microbial community to plant composition changes in broad-leaved forests of the karst area in Mid-Subtropical China.

The rapid growth and expansion ofCryptomeria japonica (Thunb. ex L. f.) D. Don in karst area strongly affects plant composition of native deciduous broad-leaved forest, which seriously threat ecosystem function and service. Given the importance of soil microorganisms in regulating nutrients cycling and plant species coexistence, understanding soil microbial attributes and their relationships with soil and vegetation features in forests harboring different C. japonica abundance will help understanding the drivers of ecosystem function changes. Here we examined the diversity and composition of soil bacterial and fungal communities and their correlations with plant diversity as well as soil physicochemical properties in karst broad-leaved forests with different relative abundances of C. japonica (i.e., a high, moderate, low and no proportion level with a stem density of 1,487, 538, 156 and 0 plant/hm2, respectively) in Mid-Subtropical China. We found that soil pH decreased while soil water content (SWC), total nitrogen (TN), total phosphorus (TP) and total potassium (TK) tended to increase with the increase in C. japonica abundance. In contrast, soil available nitrogen (AN), available phosphorus (AP) and available potassium (AK) content declined by 26.1%∼49.3% under the high level of C. japonica abundance. A gradual decrease in relative abundance of Acidobacteria and Chloroflexi while a pronounced increase in relative abundance of Ascomycota and Basidiomycota were observed with increase of C. japonica abundance. Alternations in bacterial composition were closely related to changes in AP and AK, while the change of fungal structure was mainly related to SWC, soil organic carbon (SOC) and pH, indicating that bacterial community was sensitive to declines in soil available nutrients and fungal structure was sensitive to changes in soil physicochemical properties (i.e., pH and SWC) and organic carbon resource. Understory plants had the highest α-diversity in forest containing moderate abundance of C. japonica, which might be related to the high bacterial diversity. Our findings suggest conservation of soil bacterial and fungal taxa that are responsible for nutrients availability and carbon sequestration is of great significance for improving the resistance of natural deciduous broad-leaved forests to the rapid spread of C. japonica in karst areas. Moreover, Acidobacteria, Chloroflexi, Ascomycota and Basidiomycota are potential indicators for soil properties changes, which should be taken into consideration in karst forest managements.

Genome-wide analysis of the Tritipyrum WRKY gene family and the response of TtWRKY256 in salt-tolerance.

Introduction: The transcription factor WRKY is widespread in the plant kingdom and plays a crucial role in diverse abiotic stress responses in plant species. Tritipyrum, an octoploid derived from an intergeneric cross between Triticum aestivum (AABBDD) and Thinopyrum elongatum (EE), is a valuable germplasm resource for introducing superior traits of Th. elongatum into T. aestivum. The recent release of the complete genome sequences of T. aestivum and Th. elongatum enabled us to investigate the organization and expression profiling of Tritipyrum WRKY genes across the entire genome. Results: In this study, 346 WRKY genes, from TtWRKY1 to TtWRKY346, were identified in Tritipyrum. The phylogenetic analysis grouped these genes into three subfamilies (I-III), and members of the same subfamilies shared a conserved motif composition. The 346 TtWRKY genes were dispersed unevenly across 28 chromosomes, with 218 duplicates. Analysis of synteny suggests that the WRKY gene family may have a common ancestor. Expression profiles derived from transcriptome data and qPCR demonstrated that 54 TtWRKY genes exhibited relatively high levels of expression across various salt stresses and recovery treatments. Tel1E01T143800 (TtWRKY256) is extremely sensitive to salt stress and is on the same evolutionary branch as the salt-tolerant A. thaliana genes AtWRKY25 and AtWRKY33. From 'Y1805', the novel AtWRKY25 was cloned. The Pearson correlation analysis identified 181 genes that were positively correlated (R>0.9) with the expression of TtWRKY256, and these genes were mainly enriched in metabolic processes, cellular processes, response to stimulus, biological regulation, and regulation of biological. Subcellular localization and qRT-PCR analysis revealed that TtWRKY256 was located in the nucleus and was highly expressed in roots, stems, and leaves under salt stress. Discussion: The above results suggest that TtWRKY256 may be associated with salt stress tolerance in plants and may be a valuable alien gene for improving salt tolerance in wheat.

Micro-Image Strain Sensing Method for Displacement and Strain Measurement in One United Sensor.

Micro-image strain sensing (MISS) is an innovative technology to measure strain within a measurement range of ±8300 microstrains. It has been proved to be effective and satisfy all requirements in the field of structural health monitoring. However, there is still room for improvement and extend the range of measurement. In this paper, an improved method is proposed to increase the measurement range of strain and displacement. Moreover, various tests were conducted to verify the efficiency of the improved method. The results showed that the modified method is efficient and accurate and can be readily used to extend the measurement range of both strain and displacement. This research will likely help stimulate the development of multifunctional sensors to obtain abundant useful information about structures in the field of structural health monitoring. It will allow measuring strain and displacement, which require different levels of accuracy, using one unified sensor.

Evaluating the Work Productivity of Assembling Reinforcement through the Objects Detected by Deep Learning.

With the rapid development of deep learning, computer vision has assisted in solving a variety of problems in engineering construction. However, very few computer vision-based approaches have been proposed on work productivity's evaluation. Therefore, taking a super high-rise project as a research case, using the detected object information obtained by a deep learning algorithm, a computer vision-based method for evaluating the productivity of assembling reinforcement is proposed. Firstly, a detector that can accurately distinguish various entities related to assembling reinforcement based on CenterNet is established. DLA34 is selected as the backbone. The mAP reaches 0.9682, and the speed of detecting a single image can be as low as 0.076 s. Secondly, the trained detector is used to detect the video frames, and images with detected boxes and documents with coordinates can be obtained. The position relationship between the detected work objects and detected workers is used to determine how many workers (N) have participated in the task. The time (T) to perform the process can be obtained from the change of coordinates of the work object. Finally, the productivity is evaluated according to N and T. The authors use four actual construction videos for validation, and the results show that the productivity evaluation is generally consistent with the actual conditions. The contribution of this research to construction management is twofold: On the one hand, without affecting the normal behavior of workers, a connection between construction individuals and work object is established, and the work productivity evaluation is realized. On the other hand, the proposed method has a positive effect on improving the efficiency of construction management.

Soil microbial community dynamics mediate the priming effects caused by in situ decomposition of fresh plant residues.

Extreme climate events always leave numerous fresh plant materials (FOM) in forests, thus increasing the input of carbon (C) resources to soil system. The input of exogenous C may accelerate or inhibit the decomposition of soil organic carbon (SOC), which is defined as the positive or negative priming effect (PE), respectively. However, the characteristics and microbial mechanisms of PE caused by FOM remain unknown. A 110-day in situ soil incubation experiment was conducted in a subtropical forest, with 13C-labeled fresh leaves from four native species (Castanopsis fissa, CF; Pinus massoniana, PM; Machilus chekiangensis, MC; and Castanopsis chinensis, CC) serving as the FOM respectively. We measured the CO2 effluxes derived from 13C-labeled FOM and soil, and the composition and diversity of soil bacterial and fungal communities throughout the incubation to explore the correlations between PE and microbial attributes. As a result, the PE caused by FOM inputs were negative initially but became positive after 61 d. The FOM decomposition rate was positively related to PE intensity, and there was a significant difference between coniferous and broadleaved species in the middle period of the study. More than 77% of the total C lost from FOM was emitted as CO2, indicating that FOM-C serves as an energy resource for soil microbes. The α-diversity of the bacterial community at genus-level showed significantly positive correlation with PE at 24 d, and the composition of bacterial community at OTU-level had a marked relationship with the PE between 24-110 d. The relationship between fungal community diversity and composition with PE was only observed at 7 and 110 d, respectively. This study firstly investigated the patterns of PE resulted from numerous FOM input, and the results suggested that soil bacterial community, in particular the Actinobacteria phyla, played a more important role in triggering such PEs than fungal community.

Horizontal displacement monitoring method of deep foundation pit based on laser image recognition technology.

Currently, inclinometers are often used to monitor the horizontal displacement of deep foundation pits; however, this method generally has a high cost and complex operation and cannot monitor in real time. In this paper, a novel monitoring method for horizontal displacement of deep foundation pits based on laser image recognition technology is proposed. By identifying the displacement of the spot produced by the laser emitter fixed at the monitoring point, the displacement of the deep foundation pit is determined. In addition, the impact of the angle is considered and eliminated. A series of experimental results indicate that this method exhibits high precision and satisfies the requirements of practical engineering. Simultaneously, it exhibits the advantages of low cost, easy operation, and real-time monitoring. It provides a novel method for the displacement monitoring of deep foundation pits.

[Aboveground biomass of natural Castanopsis carlesii-Schima superba community in Xiaokeng of Nanling Mountains, South China].

By the method of clear cutting, a measurement was made on the aboveground biomass (AGB) of 24-year old natural Castanopsis carlesii-Schima superba community in an 800 m2 plot in Xiaokeng of Nanling Mountains, South China. The distribution patterns of the total AGB in different forest layers, tree species, and tree layer organs were investigated, and the AGB regression models were constructed. The results showed that when constructing the AGB regression models, more than 12 samples would be feasible. Based on the measured AGB of 265 felled trees, the AGB models of mixed broadleaved species were AGB = 0. 128D(2.372) and AGB = 242.331(D2H)(0.947). The single tree's AGB model of C. carlesii, S. superba, and Cunninghamia lanceolata was also established. The total AGB of the forest community was 115.20 t x hm(-2), of which, the AGB of tree layer, understory layer, liana, and litter layer was 111.25, 1.01, 0.36, and 2.58 t x hm(-2), respectively. The AGB of C. carlesii and S. superba took up 39.1% and 28.7% of the tree layer AGB, respectively. The AGB of tree stem and branch-leaf occupied 81.0% and 19.0% of the tree layer AGB, respectively.

Abscisic acid in soil facilitates community succession in three forests in China.

Plants release secondary metabolites into the soil that change the chemical environment around them. Exogenous abscisic acid (ABA) is an important allelochemical whose role in successional trajectories has not been examined. We hypothesized that ABA can accumulate in the soil through successional processes and have an influence on forest dynamics. To this end, we investigated the distribution of ABA in forest communities from early to late successional stages and the response of dominant species to the gradient of ABA concentrations in three types of forests from northern to southern China. Concentrations of ABA in the soils of three forest types increased from early to late successional stages. Pioneer species' litters had the lowest ABA content, and their seed germination and seedling early growth were the most sensitive to the inhibitory effect of ABA. Mid- and late-successional species had a much higher ABA content in fallen leaves than pioneer species, and their seed germination and seedling early growth were inhibited by higher concentrations of ABA than pioneers. Late-successional species showed little response to the highest ABA concentration, possibly due to their large seed size. The results suggest that ABA accumulates in the soil as community succession proceeds. Sensitivity to ABA in the early stages, associated with other characteristics, may result in pioneer species losing their advantage in competition with late-successional species in an increasingly high ABA concentration environment, and being replaced by ABA-tolerant, late-successional species.

Tolosa-Hunt syndrome with reversible dissection aneurysm.

A 49-year-old female presented with recurrent intolerable right retro-orbital pain, ptosis and diplopia for 4 months. Neurological evaluation revealed right oculomotor nerve and abducent nerve injuries. Neuroimaging found enlarged right cavernous sinus, right intracavernous carotid dissection aneurysm and a stenosis proximal to it. Tolosa-Hunt syndrome (THS) was suggested and treated with steroid. The clinical symptoms were alleviated after the treatment. After 3 months of follow-up cerebral angiography showed the lesions of the right intracavernous carotid stenosis and the dissection almost disappeared. Therefore, we proposed that the dissection and the stenosis are directly induced by the inflammation of THS.

Atorvastatin reduces plaque vulnerability in an atherosclerotic rabbit model by altering the 5-lipoxygenase pathway.

OBJECTIVE: The 5-lipoxygenase catalyzed formation of leukotriene lipid mediators is a mediator for inflammatory response in arteries. The present study investigated the relationship between atorvastatin and the 5-lipoxygenase pathway in an atherosclerotic rabbit model. METHODS: Thirty male New Zealand White Rabbits were randomized into negative control, positive control and atorvastatin groups. At week 4, the rabbits were subjected to carotid balloon-dilation injury or carotid balloon-dilation injury, followed by treatment with atorvastatin. At week 12, all the animals were sacrificed. Plasma lipids, LTD(4), and 15-epi-lipoxin A(4) were measured using the enzymatic endpoint method and ELISA, respectively. RT-PCR was performed to detect the gene expression of 5-lipoxygenase-activating protein and cysLT1R in rabbit carotid arteries. Finally, histological analysis was used to evaluate the pathophysiological changes of rabbit carotid arteries. RESULTS: The results showed atorvastatin markedly lowered serum lipids and LTD(4) levels compared with the control group. Similarly, mRNA expression of 5-lipoxygenase-activating protein and cysLT1R was significantly inhibited by atorvastatin. Decreased carotid plaque instability was evident in atorvastatin-treated animals, as demonstrated by a thickened elastic layer, less neointima hyperplasia and macrophage proliferation. CONCLUSIONS: Atorvastatin may stabilize carotid plaque by regulating the 5-lipoxygenase pathway in atherosclerotic rabbits and delay the progression of atherosclerosis by exerting anti-inflammatory effects.

Montelukast inhibits matrix metalloproteinases expression in atherosclerotic rabbits.

BACKGROUND: Matrix metalloproteinases (MMPs) play important roles in the development and destabilization of atherosclerotic plaques. It is known that montelukast inhibits neointimal hyperplasia. However, the underlying mechanisms for the inhibitory effects of montelukast on neointimal formation have been poorly defined. METHODS: Thirty-six male New Zealand White rabbits were randomized as normal control, placebo (0.9% NaCl, 1.5 ml/kg/day, via intraperitoneal injection), atorvastatin (atorvastatin, 1.5 mg/kg/day, orally) and montelukast groups (montelukast, 1.5 mg/kg/day, via intraperitoneal injection). Atherosclerosis was induced by balloon-injury and high-cholesterol (HC) diet. Serum lipids were measured at 0, 8 and 12 weeks. After 12 weeks, the rabbits were sacrificed and histopathological changes examined. Immunohistochemistry and reverse transcription-polymerase chain reaction were used to measure the expression of MMP-2 and MMP-9 in the plaques. RESULTS: It was found that montelukast reduced neointimal formation, decreased macrophage accumulation, and increased smooth muscle cells. It also attenuated the expression of MMP-2 and MMP-9 in atherosclerotic plaques, but it had no effect on plasma lipid levels. CONCLUSION: These data indicate that montelukast inhibits neointimal hyperplasia in association with decreased expression of MMP-2 and MMP-9 independent of plasma lipid levels in atherosclerotic plaques after vascular injury in hyperlipidemic rabbits.

[Effects of montelukast on atherosclerosis and monocyte chemoattractant protein-1 expression in ahypercholesterolemic rabbit model.].

OBJECTIVE: To investigate the effects of montelukast on atherosclerosis and monocyte chemoattractant protein-1 expression in a hypercholesterolemic rabbit model. METHODS: Thirty four male New Zealand white rabbits were randomized into four groups including normal control group (n = 6), placebo group (n = 8), atorvastatin group (1.5 mgxkg(-1)xd(-1), beginning at 8(th) weeks for 4 weeks, n = 10) and montelukast group (1 mgxkg(-1)xd(-1), beginning at 8(th) weeks for 4 weeks, n = 10). Rabbits except those in normal control group were fed a high cholesterol diet for 12 weeks. Serum lipids were measured at 0, 8 and 12 weeks after intervention. The intima/media ratio, percentages of macrophages or smooth muscle cells in intima and the expression of MCP-1 mRNA were examined. RESULTS: Atherosclerosis was evidenced in placebo group and atorvastatin or montelukast treatment significantly reduced neointima (0.32 +/- 0.12 and 0.34 +/- 0.10 vs. 1.12 +/- 0.36, P < 0.05) and macrophage content [(9.8 +/- 4.6)% and (11.2 +/- 3.7)% vs. (34.6 +/- 8.8)%, P < 0.05], increased SMC content [(18.6 +/- 6.9)% and (19.2 +/- 8.6)% vs. (5.2 +/- 2.3)%, P < 0.05] and inhibited expression of MCP-1 mRNA (0.42 +/- 0.08 and 0.40 +/- 0.06 vs. 2.36 +/- 0.48, P < 0.01). Montelukast had similar anti-atherogenetic effects as atorvastatin but had no influence on plasma lipids. CONCLUSIONS: Montelukast could attenuate atherosclerosis in this hypercholesterolemic rabbit model which might be attributed to its anti-inflammatory effects.

IL-18 accelerates the cell apoptosis by up-regulating cysteinyl leukotriene 2 receptor expression in human umbilical vein endothelial cells at the early stage of administration.

The purpose of the present study is to identify whether interleukin (IL)-18 can modulate cysteinyl leukotriene 2 receptor (CysLT2R) expression in Human Umbilical Vein Endothelial Cells (HUVECs) and how it influences the cell death. According to the results from real-time reverse transcription PCR, confocal laser scanning microscopy, and western blotting, a dose-dependent augmentation of CysLT2R protein expression in HUVECs was triggered by IL-18 for the first 2 h followed by down-regulation within the next 22 h after IL-18 administration. The flow cytometry showed that non-selective CysLT1R and CysLT2R antagonist BAY-u9773 could attenuate the early stage apoptosis mediated by IL-18 whereas CysLT1R antagonist Montelukast couldn't. Also, pretreatment with BAY-u9773 suppressed calcium influx of HUVECs induced by IL-18 whereas Montelukast didn't work. The observation that progression of cell death aggravated by IL-18 could be attenuated by BAY-u9773 may offer a chance to develop a novel way to treat arteriosclerosis.