Diet supplementation with sodium pyruvate increases sleep time and lifespan in Drosophila model.

Sodium pyruvate is a natural metabolite commonly used in biological fields, including cell culture. This study investigated the effects of sodium pyruvate on the lifespan and other physiological characters of Drosophila melanogaster, by measuring feeding, fecundity, and spontaneous activity. The results indicated that 0.2 mol/L of sodium pyruvate increased the median lifespan of female flies by 8.33%. Moreover, the group sleep duration of female flies significantly increased by 53.98% when exposed to the sodium pyruvate concentration. However, the intake of sodium pyruvate did not significantly affect the fecundity or food intake of female flies. Our results also show that the effect of extending lifespan and increasing sleep time was dose-dependent and sex-specific. Our data provides the role of sodium pyruvate as an insect culture additive by enhancing survival.

Chronic Consumption of Trehalose Reduces Lifespan in Drosophila Model.

Trehalose has been widely used as a kind of food additives. But in recent years, with several new studies of trehalose, some harmful effects had also been found. Drosophila melanogaster was used as a model organism to explore whether trehalose affects the lifespan. The results showed that high concentrations of trehalose could significantly shorten the lifespan of female flies by 12.5%, when compared to controls.

Luteolin alleviated damage caused by blue light to Drosophila.

Short-wavelength blue light is commonly found in daily life and is harmful to health. In this experiment, we investigated the effect of luteolin on the survival time of Drosophila under the blue light condition of 3000 Lux using Drosophila as the model organism. The results showed that luteolin alleviated the damage suffered by Drosophila under blue light irradiation, significantly prolonged the survival time of Drosophila, prolonged the survival time of male Drosophila in the heat stress assay, increased the activity of female Drosophila in the spontaneous activity assay, and increased the egg production of female Drosophila at the highest concentration, and there was no significant difference in the food intake experiment. We suggest that the increase in survival time of Drosophila under blue light conditions is due to the function of luteolin in resisting oxidative stress.

Differential analysis of negative geotaxis climbing trajectories in Drosophila under different conditions.

The decline of Drosophila climbing behavior is one of the common phenomena of Drosophila aging. The so-called negative geotaxis refers to the natural upward climbing behavior of Drosophila melanogaster after it oscillates to the bottom of the test tube. The strength of climbing ability is regarded as the index of aging change of D. melanogaster. At present, many laboratories use the percentage of 10 fruit flies climbing a specific height in 5 s as a general indicator of the climbing ability of fruit flies. This group research index ignores the climbing performance of a single fruit fly, and the climbing height belongs to the concept of vertical distance in physics, which cannot truly and effectively reflect the concept of curve distance in the actual climbing process of fruit flies. Therefore, based on the image processing algorithm, we added an experimental method to draw the climbing trajectory of a single fruit fly. By comparing the differences in climbing behavior of fruit flies under different sex, group or single, oscillation condition or rotation inversion condition, we can find that the K-Nearest Neighbor target detection algorithm has good applicability in fruit fly climbing experiment, and the climbing ability of fruit flies decreases with age. Under the same experimental conditions, the climbing ability of female fruit flies was greater than that of male fruit flies. The climbing track length of a single fruit fly can better reflect the climbing process of a fruit fly.

Sex-specific effects of PET-MPs on Drosophila lifespan.

In recent years, as an emerging pollutant, microplastic (MPs) pollution is gradually becoming a research hotspot. MPs are ubiquitous in the entire ecological environment. Organisms can be exposed to MPs via inhalation or ingestion. In view of the widespread of MPs pollution, the impact of MPs on biology should be further investigated. In previous experiments, we have conducted research on the physiology of Drosophila exposed to polyethylene terephthalate microplastics (PET-MPs). However, will the lifespan of Drosophila be affected under long-term PET-MPs exposure? The analysis of variance analysis of our experimental results indicates that there are significant differences between males and females, F(1, 895) = 68.19, p < 0.001, between PET-MPs concentration, F(3, 895) = 8.11, p < 0.001. There are also significant interactions between sex and MP concentration, F(3, 895) = 4.00, p < 0.01. For Cox and log-rank test, 1 g/L of PET-MPs prolongs the lifespan of male flies. The reason for this phenomenon may be the hormesis effect.

Nanoemulsion Co-Loaded with XIAP siRNA and Gambogic Acid for Inhalation Therapy of Lung Cancer.

Lung cancer is a leading cause of cancer mortality worldwide, with a 5-year survival rate of less than 20%. Gambogic acid (GA) is a naturally occurring and potent anticancer agent that destroys tumor cells through multiple mechanisms. According to the literature, one of the most potent inhibitors of caspases and apoptosis currently known is the X-linked Inhibitor of Apoptosis Protein (XIAP). It is highly expressed in various malignancies but has little or no expression in normal cells, making it an attractive target for cancer treatment. Here we report the development of a chitosan (CS)-based cationic nanoemulsion-based pulmonary delivery (p.d.) system for the co-delivery of antineoplastic drugs (GA) and anti-XIAP small interfering RNA (siRNA). The results showed that the chitosan-modified cationic nanoemulsions could effectively encapsulate gambogic acid as well as protect siRNA against degradation. The apoptosis analysis confirmed that the cationic nanoemulsions could induce more apoptosis in the A549 cell line. In addition, most drugs and siRNAs have a long residence time in the lungs through pulmonary delivery and show greater therapeutic effects compared to systemic administration. In summary, this work demonstrates the applicability of cationic nanoemulsions for combined cancer therapy and as a promising approach for the treatment of lung cancer.

Apoptotic investigation of brain tissue cells in dogs naturally infected by canine distemper virus.

BACKGROUND: Canine distemper caused by canine distemper virus that belongs to the Morbillivirus genus of the Paramyxoviridae family is still a global epidemic significant infectious disease, especially in pet dogs in China and serious harm to the development of the dog industry. It has been known that apoptosis caused by the canine distemper virus can show in culture cells, lymphoid tissues, and the cerebellum. However, its occurrence in brain tissue cells remains unclear. To investigate the relationship among canine distemper infecting brain tissues, apoptosis in brain tissue cells, and demyelinating pathogenesis was investigated. METHODS: 16 naturally infected dogs that exhibited clinical signs of CD and tested positive for the anti-CDV monoclonal antibody and six healthy dogs that served as the control, were used in the research. Brain specimens were divided into the cerebrum, brain stem, and cerebellum embedded in paraffin and made the sections respectively. Approximately 5 µm-thick sections were stained by hematoxylin-eosin, methyl green pyronin, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling technique, and immunohistochemistry. CDV nucleocapsid protein was detected by immune streptavidin-biotinylated peroxidase complex. RESULTS: Alterations in the brain tissues of CDV-infected dogs involved both various cells and nerve fibers. CDV had varying degrees of cytotropism to all brain tissue cells; apoptosis also occurred in all brain cells, especially in the endothelia of cerebral vessels, astrocytes, oligodendrocytes, and ependymal cells, the more serious infection, the more obvious apoptosis. Serious infections also involved the pyramidal and Purkinje cells. The nervous fibers exhibited demyelinating lesions (showed small multifocal vacuole), and some axonal neuron atrophy gradually disappeared (formed large vacuole). CONCLUSIONS: Apoptosis in brain tissue cells was mainly related to the propagation path and cytotropism of CDV. The apoptosis of astrocytes, oligodendrocytes, and some neurons may play a significant role in the demyelinating pathogenesis in dogs with acute canine distemper. A lot of diverse nervous signs shown in the clinic may be related to different neuron apoptosis.

Proteomic analysis of the antimicrobial effects of sublethal concentrations of thymol on Salmonella enterica serovar Typhimurium.

Salmonella enterica serovar Typhimurium is an important foodborne pathogen that causes serious and extensive food contamination as well as disease and death worldwide. Considering the increasing severity of antibiotic resistance, antibiotic alternatives are urgently needed. As a natural biocide and a component of some essential oils from herbs, thymol is capable of killing various bacteria through a potentially unique mechanism, although the targets of thymol have not been completely elucidated. In this study, the variation in the whole proteome of Salmonella after thymol stress was evaluated using the SWATH multiplex technique. The strain Salmonella Typhimurium CVCC541 was treated with a sublethal concentration (75 µg/mL) of thymol, which rapidly increased the permeability of bacterial membranes at the tested concentration. Thymol destroyed the integrity of the bacterial membrane, as observed by transmission electron microscopy. The proteomes of the treated and untreated cells were characterized after an 8-h treatment. The proteomic analysis of thymol-treated cells indicated that 144 proteins exhibited upregulation or downregulation compared with the control cells, particularly those involved in cellular structure and metabolism. The results of this study showed that thymol may play an antimicrobial role in altering the membrane permeability, virulence change, and antioxidant response of Salmonella Typhimurium. The results of the present study provide an improved understanding of the proteomic response of Salmonella Typhimurium to thymol stress, including the identification of promising targets for the future exploration of innovative approaches to control Salmonella Typhimurium.

Pro-apoptosis effects of protocatechuic acid in the early stage of infectious bursal disease virus infection.

Infectious bursal disease virus (IBDV) is a very important small RNA virus in the family of Birnaviridae, which can cause severe immunosuppressive effects and pathological damages in young chickens. It can replicate in bursal lymphocytes and impede the growth and development of B cells, finally causing bursal lymphocytes apoptosis. Previous results have shown that protocatechuic acid (PCA) as an important phenolic compound could effectively improve the survival rate of chickens infected with IBDV. The current study aimed to explore how PCA influenced the pathogenesis of IBDV, especially lymphocyte apoptosis in the process of IBDV infection. The results showed that PCA could effectively alleviate bursal pathological changes at the early stage of IBDV invasion. Moreover, bursal lymphocyte apoptosis for tissue section samples was largely elevated by PCA by using the terminal dexynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) method while the bursal lymphocyte apoptosis ratio was also increased by PCA by flow cytometry in the early stage of IBDV infection in vivo. Meanwhile, PCA could promote non-lymphocyte apoptosis in vitro. Further study displayed that the potential mechanisms mainly relied on regulation of the expressions of pro-apoptotic protein Bax and anti-apoptotic Bcl-2, thus speeding up the process of IBDV-infected cell apoptosis and preventing virus infection. Meanwhile, the results displayed that the PI3K/Akt and NF kappa B signal pathways might play an important role in promoting cell apoptosis after IBDV infection. Overall, PCA as a potent antiviral drug precursor is expected to be applied in the poultry industry as a substitute for clinical antiviral application.

Chemokine receptor CCR5 and CXCR4 might influence virus replication during IBDV infection.

Both CCR5 and CXCR4 are important chemokine receptors and take vital role in migration, development and distribution of T cells, however, whether they will influence the process of T cell infiltration into bursa of Fabricius during infectious bursal disease virus (IBDV) infection is unclear. In the current study, CCR5 and CXCR4 antagonists, Maraviroc and AMD3100, were administrated into chickens inoculated with IBDV, and the gene levels of IBDV VP2, CCR5, CXCR4 and related cytokines were determined by real-time PCR. The results showed that large number of T cells began to migrate into the bursae on Day 3 post infection with IBDV and the mRNA of chemokine receptors CCR5 and CXCR4 began to increase on Day 1. Moreover, antagonist treatments have increased the VP2, CCR5 and CXCR4 gene transcriptions and influenced on the gene levels of IL-2, IL-6, IL-8, IFN-γ, TGF-ß4, MHC-I and MDA5. In conclusion, the chemokine receptors CCR5 and CXCR4 might influence virus replication during IBDV infection and further study would focus on the interaction between chemokine receptors and their ligands.

M protein is sufficient for assembly and release of Peste des petits ruminants virus-like particles.

Peste des petits ruminants virus (PPRV), belonging to paramyxoviruses, has six structure proteins (such as matrix protein (M), nucleocapsid proteins (N), fusion protein (F) and hemagglutinin protein (H)) and could cause high morbidity and mortality in sheep and goats. Although a vaccine strain of PPRV has been rescued and co-expression of M and N could yield PPRV-like particles, the roles of structure proteins in virion assembly and release have not been investigated in detail. In this study, plasmids carrying PPRV cDNA sequences encoding the N, M, H, and F proteins were expressed in Vero cells. The co-expression of all four proteins resulted in the release of virus-like particles (VLPs) with similar release efficiency to that of authentic virions. Moreover, the co-expression of M together with F also resulted in efficient VLPs release. In the absence of M protein, the expression of no combination of the other proteins resulted in particle release. In summary, a VLPs production system for PPRV has been established and M protein is necessary for promoting the assembly and release of VLPs, of which the predominant protein is M protein. Further study will be focused on the immunogenicity of the VLPs.

Transcription profiles of the responses of chicken bursae of Fabricius to IBDV in different timing phases.

BACKGROUND: Infectious bursal disease virus (IBDV) infection causes immunosuppression in chickens and increases their susceptibility to secondary infections. To explore the interaction between host and IBDV, RNA-Seq was applied to analyse the transcriptional profiles of the responses of chickens' bursas of Fabricius in the early stage of IBDV infection. RESULTS: The results displayed that a total of 15546 genes were identified in the chicken bursa libraries. Among the annotated genes, there were 2006 and 4668 differentially expressed genes in the infection group compared with the mock group on day 1 and day 3 post inoculation (1 and 3 dpi), respectively. Moreover, there were 676 common up-regulated and 83 common down-regulated genes in the bursae taken from the chickens infected with IBDV on both 1 and 3 dpi. Meanwhile, there were also some characteristic differentially expressed genes on 1 and 3 dpi. On day 1 after inoculation with IBDV, host responses mainly displayed immune response processes, while metabolic pathways played an important role on day three post infection. Six genes were confirmed by quantitative reverse transcription-PCR. CONCLUSIONS: In conclusion, the differential gene expression profile demonstrated with RNA-Seq might offer a better understanding of the molecular interactions between host and IBDV during the early stage of infection.

Isolation of a novel serotype strain of infectious bronchitis virus ZZ2004 from ducks in China.

In chickens, the infectious bronchitis virus (IBV) often causes respiratory distress, a decrease in egg production, poor egg quality, and occasional nephritis. However, ZZ2004, a Chinese isolate of IBV, was obtained from ducks with clinical growth suppression and mild respiratory symptoms that had been reared with chickens in the central region of China. Virus isolation, virus neutralization testing, and RT-PCR were employed to identify the causative pathogen, while sequence alignment was used to analyze gene variations of the S1 subunit and M genes. The results showed that the ducks were infected with IBV due to the emergence of a dwarfing phenotype and the death of embryos between 48 and 144 h post-inoculation. RT-PCR also confirmed the presence of the expected fragment sizes of the S1 subunit and M genes by RT-PCR. Meanwhile, the results of the virus neutralization test indicated that the strains of JX/99/01, GD, SAIBK, LDT3 showed cross-reactivity with the ZZ2004 isolate, and hardly any cross-neutralization of IBV ZZ2004 was observed with the strains of M41, H120, Gray, Holte, or Aust-T. Phylogenetic analysis suggested that there were large differences between ZZ2004 and other IBV reference strains on the S1 subunit. Meanwhile, homologies in the nucleotide and amino acid sequences of the M gene of IBV ZZ2004 were 86.9-92.0 % and 91.1-93.9 %, respectively, compared with 35 other IBV reference strains derived from different regions. This result revealed that there were conspicuous variations among the selected strains. Furthermore, the results showed that the prevalent strains of IBV in ducks had no antigen homology with the vaccine strains widely used in China except the LDT3-strain, making it urgent to explore and develop new IBV vaccines.

Tissue distribution and developmental changes of ghrelin and GOAT expression in broiler chickens during embryogenesis.

Ghrelin plays important roles, such as regulating growth hormone release and energy metabolism, but little is known about its developmental changes in the proventriculi of chicken embryos. This study was designed to elucidate the distributions and developmental changes of ghrelin and ghrelin-O-acyltransferase (GOAT) expression in broiler embryos using qRT-PCR and immunohistochemistry. Our results demonstrated the following: (1) on E18, ghrelin and GOAT are ubiquitously expressed in every tissue examined. The expression level of ghrelin mRNA was the highest in the proventriculus, reaching a level that was 50-fold higher than that in the hypothalamus, while GOAT mRNA expression was low in the proventriculus and it was only 67.6% as high as that of hypothalamus; (2) ghrelin and GOAT mRNA expression were detected in the proventriculus on E9, but only at 1.9% and 1.7% of the level expressed on E18, respectively, and their expression levels increased rapidly from E18 to E21. There was similar developmental pattern in the ghrelin and GOAT mRNA expression; and (3) ghrelin-immunopositive cells were first detected in the proventriculus on E15, were located only in the compound tubular glands of the proventriculus, and were of the closed-cell type. The density of ghrelin-immunopositive cells increased significantly from E15 to E21. These results suggest that ghrelin may be an important regulating factor that plays a vital role during the development of chicken embryos.

Effects of dietary supplementation of fermented Artemisia argyi on growth performance, slaughter performance, and meat quality in broilers.

Artemisia argyi (AA) is promising as a potential feed additive. Microbial fermentation is beneficial to the degradation of cell walls and the better release of bioactive compounds of AA. However, there are few reports on the application of fermented AA as a feed additive for broilers. The present study intended to evaluate the application value of fermented AA as a feed additive for broilers by examining the effects of the dietary supplementation of Aspergillus niger-fermented AA and unfermented AA on growth performance, slaughter performance, and meat quality of brokers. A total of 360 newly hatched (1-day-old) broilers with similar body weight were randomly divided into the following 5 groups: basal diet group as control (C) group, basal diet +3% unfermented AA (E1) group, basal diet + 1% fermented AA (E2) group, basal diet + 3% fermented AA (E3) group, basal diet + 5% fermented AA (E4) group. Each group included 6 replicates with 12 broilers per replicate, and the feeding trail lasted for 48 d. Body weight and feed intake were recorded every 2 wk, and the feed gain ratio was calculated to assess growth performance. At 42 d, 6 broilers from each group were slaughtered, and the carcass traits were calculated. The results showed that compared with the control group, Aspergillus Niger could effectively destroy AA fiber, which contributed to better release of AA bioactive compounds. Moreover, dietary supplementation with AA could improve the growth performance of broilers (P < 0.05), and the effect of fermented AA was better than unfermented AA, especially 3% fermented AA. From 28 to 42 d, compared with the control group, the average daily gain of broilers in the group supplementation with 3% fermented AA was significantly increased (P < 0.05), and the feed-to-gain ratio was decreased (P < 0.05). At 42 d, the dressing percentage, half-eviscerated carcass percentage, eviscerated carcass percentage, and breast muscle percentage of broilers in the groups of 1, 3, and 5% fermented AA diets were significantly improved (P < 0.05), and the thigh muscle percentage of broilers in the group with 3% fermented AA diets was significantly improved (P < 0.05). Meanwhile, the meat quality of broilers in the group with fermented AA diets was also significantly improved. Birds in AA groups had higher a* value and lower shear force of breast muscle, especially the group supplementation with 3% fermented AA (P < 0.05). In conclusion, fermented AA has good application value as a potential feed additive for broilers, dietary supplementation of fermented AA can improve the production performance and meat quality of broiler chickens, of which 3% fermented AA is more effective.

Rutin intake mitigates the injury of blue light irradiation by altering aging rates of mortality in Drosophila model.

Blue light is known as one of the harmful light pollution that has complex effects on organisms. The massive use of LED lights in cities has greatly increased the frequency of human exposure to blue light, and therefore the hazards of blue light are receiving widespread attention. In our study, Drosophila was used as the model organism to explore the ability of the flavonoid rutin to resist blue light damage under the intensity of 3000 Lux. Siler model analysis was performed. Our results showed sex-specific pattern of rutin as an effective antioxidant. Rutin could help female flies to reduce the initial adult mortality and male flies to slow the increase of adult mortality under blue light irradiation, thus prolonging their average lifespan. Furthermore, after the intake of rutin, the locomotor activity of Drosophila under blue light irradiation was significantly increased, and the total sleep time was significantly decreased. In summary, our results provide preliminary support for exploring the mechanism of rutin against blue light damage.

Recent Progress in Extracellular Vesicle-Based Carriers for Targeted Drug Delivery in Cancer Therapy.

Extracellular vesicles (EVs) are small, membrane-based vesicles released by cells that play a critical role in various physiological and pathological processes. They act as vehicles for transporting a variety of endogenous cargo molecules, enabling intercellular communication. Due to their natural properties, EVs have emerged as a promising "cell-free therapy" strategy for treating various diseases, including cancer. They serve as excellent carriers for different therapeutics, including nucleic acids, proteins, small molecules, and other nanomaterials. Modifying or engineering EVs can improve the efficacy, targeting, specificity, and biocompatibility of EV-based therapeutics for cancer therapy. In this review, we comprehensively outline the biogenesis, isolation, and methodologies of EVs, as well as their biological functions. We then focus on specific applications of EVs as drug carriers in cancer therapy by citing prominent recent studies. Additionally, we discuss the opportunities and challenges for using EVs as pharmaceutical drug delivery vehicles. Ultimately, we aim to provide theoretical and technical support for the development of EV-based carriers for cancer treatment.

Underlying mechanism of Qiling Jiaogulan Powder in the treatment of broiler ascites syndrome.

Broiler ascites syndrome (AS), is a nutritional and metabolic disease that occurs in fast-growing commercial broiler chickens. AS can cause poor growth and a significant increase in the rate of broiler deaths, which has resulted in serious economic losses to the poultry industry. The classic traditional Chinese medicine Qiling Jiaogulan Powder (QLJP) has been demonstrated to have a certain therapeutic effect on broiler AS. However, its pharmacological mechanism remains to be elucidated. This study was performed to investigate the multitarget action mechanism of QLJP in the treatment of broiler AS based on network pharmacology analysis using a broiler AS model. First, all chemical components and targets of QLJP were obtained from the Traditional Chinese Medicine System Pharmacology Analysis Platform (TCMSP). Targets related to broiler AS were further obtained through the GeneCards database and the NCBI Gene sub-database. A protein-protein interaction (PPI) network was constructed. Then, enrichment analyses were performed to predict the potential mechanisms of QLJP in the treatment of broiler AS. Finally, the treatment effect of QLJP on AS was verified in a broiler AS model. Network pharmacology analysis generated 49 active ingredients and 167 core targets of QLJP, and a QLJP-single drug-target-disease network was successfully constructed. Gene enrichment analysis indicated that the core targets have played major roles in the Cell cycle, FOXO signaling pathways, etc. We demonstrated that QLJP improved clinical and organ damage symptoms and significantly reduced the ascites heart index in broilers with AS induced by administration of high-energy, high-protein diets and high-sodium drinking water in a low-temperature environment. QLJP may regulate lung oxidative stress, the cell cycle and apoptosis by activating the FOXO3a signaling pathway to interfere with the occurrence and development of AS in broilers. QLJP administration may be a good clinical strategy for the prevention and treatment of broiler AS.

Identification of the p34 Protein of African Swine Fever Virus as a Novel Viral Antigen with Protection Potential.

African swine fever (ASF) is a highly contagious disease caused by African swine fever virus (ASFV), affecting domestic and wild boars. The polyprotein pp220 of ASFV is responsible for producing the major structural proteins p150, p37, p14, p34, and p5 via proteolytic processing. The p34 protein is the main component of the ASFV core shell. However, the immunologic properties of the p34 protein in vitro and in vivo remain unclear. The results showed that the recombinant p34 protein expressed in prokaryotes and eukaryotes could react with convalescent swine sera to ASFV, suggesting that p34 is an immunogenic protein. Significantly, anti-p34 antibodies were found to inhibit the replication of ASFV in target cells. Furthermore, rabbits immunized with the recombinant C-strain of classical swine fever virus containing p34 produced both anti-p34 humoral and cellular immune responses. In addition, the p34 protein could induce a cell-mediated immune response, and a T-cell epitope on the p34 protein was identified using immunoinformatics and enzyme-linked immunospot (ELIspot) assay. Our study demonstrates that the p34 protein is a novel antigen of ASFV with protective potential.

Effect of Qiling Jiaogulan Powder on Pulmonary Fibrosis and Pulmonary Arteriole Remodeling in Low-Temperature-Exposed Broilers.

Chinese herbal medicine plays an important role in regulating the nutritional metabolism of poultry and maintaining or improving normal physiological functions and animal health. The present study investigated the effects of dietary supplementation with Qiling Jiaogulan Powder (QLJP) on pulmonary fibrosis and pulmonary arteriole remodeling in low temperature-exposed broilers. Seven-day-old Ross 308 broilers (n = 240) were reared adaptively to 14 days of age. The broilers were randomly divided into six groups: A control group (basal diet and normal feeding temperature); model group (basal diet); low-, medium- and high-dose QLJP groups (basal diet supplemented with 1 g/kg, 2 g/kg, 4 g/kg QLJP); and L-Arg group (basal diet supplemented with 10 g/kg L-arginine). Additionally, all the broilers, except the broilers in the control group, from the age of 14 days old, had a house temperature continuously lowered by 2 °C each day until it reached 12 °C at 21 days of age, and the low temperature was maintained until the end of the experiment. There were four replicates per group and 10 birds per replicate. The results showed that the structure of the lung tissue was clearer and basically intact in the broilers in the QLJP groups, with a small number of collagen fibers formed, and the content of hydroxyproline (HYP) was significantly reduced. QLJP improved pulmonary arteriole lesions, such as tunica media thickening, intimal hyperplasia, arterial wall hypertrophy, and lumen narrowing. QLJP reduced the relative media thickness (%) and relative medial area (%) of the pulmonary arteriole, and significantly decreased the expression level of the alpha-smooth muscle actin (α-SMA) protein in pulmonary arteriole, which alleviated pulmonary arteriole remodeling. The quantitative real-time PCR (qPCR) and enzyme-linked immunosorbent assay (ELISA) results showed that QLJP treatment significantly reduced the gene and protein levels of transforming growth factor-beta l (TGF-ß1) and Smad2 in the lung and downregulated the gene and protein levels of collagen type I alpha 1 (COL1A1) and matrix metalloproteinase 2 (MMP2). In conclusion, the results of our study suggested that dietary supplementation with QLJP improved pulmonary fibrosis and pulmonary arteriole remodeling by inhibiting the expression of genes related to the TGF-ß1/Smad2 signaling pathway and inhibited the occurrence and development of pulmonary arterial hypertension in low-temperature-exposed broilers.