Sja-let-7 suppresses the development of liver fibrosis via Schistosoma japonicum extracellular vesicles.

Schistosomiasis is a fatal zoonotic parasitic disease that also threatens human health. The main pathological features of schistosomiasis are granulomatous inflammation and subsequent liver fibrosis, which is a complex, chronic, and progressive disease. Extracellular vesicles (EVs) derived from schistosome eggs are broadly involved in host-parasite communication and act as important contributors to schistosome-induced liver fibrosis. However, it remains unclear whether substances secreted by the EVs of Schistosoma japonicum, a long-term parasitic "partner" in the hepatic portal vein of the host, also participate in liver fibrosis. Here, we report that EVs derived from S. japonicum worms attenuated liver fibrosis by delivering sja-let-7 into hepatic stellate cells (HSCs). Mechanistically, activation of HSCs was reduced by targeting collagen type I alpha 2 chain (Col1α2) and downregulation of the TGF-ß/Smad signaling pathway both in vivo and in vitro. Overall, these results contribute to further understanding of the molecular mechanisms underlying host-parasite interactions and identified the sja-let-7/Col1α2/TGF-ß/Smad axis as a potential target for treatment of schistosomiasis-related liver fibrosis.

Staphylococcus pseudintermedius induces pyroptosis of canine corneal epithelial cells by activating the ROS-NLRP3 signalling pathway.

Staphylococcus pseudintermedius (S. pseudintermedius) is a common pathogen that causes canine corneal ulcers. However, the pathogenesis remained unclear. In this study, it has been demonstrated that S. pseudintermedius invaded canine corneal epithelial cells (CCECs) intracellularly, mediating oxidative damage and pyroptosis by promoting the accumulation of intracellular reactive oxygen species (ROS) and activating the NLRP3 inflammasome. The canine corneal stroma was infected with S. pseudintermedius to establish the canine corneal ulcer model in vivo. The intracellular infectious model in CCECs was established in vitro to explore the mechanism of the ROS - NLRP3 signalling pathway during the S. pseudintermedius infection by adding NAC or MCC950. Results showed that the expression of NLRP3 and gasdermin D (GSDMD) proteins increased significantly in the infected corneas (p < 0.01). The intracellular infection of S. pseudintermedius was confirmed by transmission electron microscopy and immunofluorescent 3D imaging. Flow cytometry analysis revealed that ROS and pyroptosis rates increased in the experimental group in contrast to the control group (p < 0.01). Furthermore, NAC or MCC950 inhibited activation of the ROS - NLRP3 signalling pathway and pyroptosis rate significantly, by suppressing pro-IL-1ß, cleaved-IL-1ß, pro-caspase-1, cleaved-caspase-1, NLRP3, GSDMD, GSDMD-N, and HMGB1 proteins. Thus, the research confirmed that oxidative damage and pyroptosis were involved in the process of CCECs infected with S. pseudintermedius intracellularly by the ROS - NLRP3 signalling pathway. The results enrich the understanding of the mechanisms of canine corneal ulcers and facilitate the development of new medicines and prevention measures.

Molecular and functional characterization of Schistosoma japonicum annexin A13.

Schistosomiasis is a neglected tropical disease that affects humans and animals in tropical and subtropical regions worldwide. Schistosome eggs are responsible for the pathogenesis and transmission of schistosomiasis, thus reducing egg production is vital for prevention and control of schistosomiasis. However, the mechanisms underlying schistosome reproduction remain unclear. Annexin proteins (ANXs) are involved in the physiological and pathological functions of schistosomes, but the specific regulatory mechanisms and roles of ANX A13 in the development of Schistosoma japonicum and host-parasite interactions remain poorly understood. Therefore, in this study, the expression profiles of SjANX A13 at different life cycle stages of S. japonicum were assessed using quantitative PCR. In addition, the expression profiles of the homolog in S. mansoni were analyzed in reference to public datasets. The results of RNA interference showed that knockdown of SjANX A13 significantly affected the development and egg production of female worms in vivo. The results of an immune protection assay showed that recombinant SjANX A13 increased production of immunoglobulin G-specific antibodies. Finally, co-culture of S. japonicum exosomes with LX-2 cells using a transwell system demonstrated that SjANX A13 is involved in host-parasite interactions via exosomes. Collectively, these results will help to clarify the roles of SjANX A13 in the development of S. japonicum and host-parasite interactions as a potential vaccine candidate.

Sja-Let-7 Attenuates Carbon Tetrachloride-Induced Liver Fibrosis in a Mouse Model via Col1α2.

Liver fibrosis (LF) is a chronic progressive disease with no definitive treatment. The aim of this study was to assess helminth-derived molecules as potential therapeutic targets to prevent or reverse LF. A mouse model of carbon tetrachloride (CCL4)-induced LF was established and sja-let-7 was overexpressed by treatment with a miRNA agomir once per week. After four weeks, serum biochemistry, hepatic hydroxyproline content measurements, liver histology, mRNA expression profiling of fibrotic markers, the dual-luciferase reporter assay, and fluorescence in situ hybridization (FISH) were performed. Administration of the sja-let-7 agomir markedly ameliorated hepatosplenomegaly and reduced the liver hydroxyproline content. Liver histological analysis showed significant reductions in collagen deposition in the sja-let-7 agomir-treated mice. Additionally, the mRNA levels of both pro-fibrotic markers and pro-inflammatory cytokines were diminished after treatment. Furthermore, the dual-luciferase reporter assay and FISH identified the α2 chain of collagen type 1 (Col1α2) as the direct target of sja-let-7. Accordingly, the progression of LF was attenuated by targeting Col1α2 and the TGF-ß/Smad signaling pathway.

Targeted delivery of a PD-1-blocking scFv by CD133-specific CAR-T cells using nonviral Sleeping Beauty transposition shows enhanced antitumour efficacy for advanced hepatocellular carcinoma.

BACKGROUND: CD133 is considered a marker for cancer stem cells (CSCs) in several types of tumours, including hepatocellular carcinoma (HCC). Chimeric antigen receptor-specific T (CAR-T) cells targeting CD133-positive CSCs have emerged as a tool for the clinical treatment of HCC, but immunogenicity, the high cost of clinical-grade recombinant viral vectors and potential insertional mutagenesis limit their clinical application. METHODS: CD133-specific CAR-T cells secreting PD-1 blocking scFv (CD133 CAR-T and PD-1 s cells) were constructed using a sleeping beauty transposon system from minicircle technology, and the antitumour efficacy of CD133 CAR-T and PD-1 s cells was analysed in vitro and in vivo. RESULTS: A univariate analysis showed that CD133 expression in male patients at the late stage (II and III) was significantly associated with worse progression-free survival (PFS) (P = 0.0057) and overall survival (OS) (P = 0.015), and a multivariate analysis showed a trend toward worse OS (P = 0.041). Male patients with advanced HCC exhibited an approximately 20-fold higher PD-L1 combined positive score (CPS) compared with those with HCC at an early stage. We successfully generated CD133 CAR-T and PD-1 s cells that could secrete PD-1 blocking scFv based on a sleeping beauty system involving minicircle vectors. CD133 CAR-T and PD-1 s cells exhibited significant antitumour activity against HCC in vitro and in xenograft mouse models. Thus, CD133 CAR-T and PD-1 s cells may be a therapeutically tractable strategy for targeting CD133-positive CSCs in male patients with advanced HCC. CONCLUSIONS: Our study provides a nonviral strategy for constructing CAR-T cells that could also secrete checkpoint blockade inhibitors based on a Sleeping Beauty system from minicircle vectors and revealed a potential benefit of this strategy for male patients with advanced HCC and high CD133 expression (median immunohistochemistry score > 2.284).

Raman Spectroscopy to Enhance Investigative Lead Information in Automotive Clearcoats.

A new method to determine the make and model of a vehicle from an automotive paint sample recovered at the crime scene of a vehicle-related fatality such as a hit-and-run using Raman microscopy has been developed. Raman spectra were collected from 118 automotive paint samples from six General Motors (GM) vehicle assembly plants to investigate the discrimination power of Raman spectroscopy for automotive clearcoats using a genetic algorithm for pattern recognition that incorporates model inference and sample error in the variable selection process. Each vehicle assembly plant pertained to a specific vehicle model. The spectral region between 1802 and 697 cm-1 was found to be supportive of the discrimination of these six GM assembly plants. By comparison, only one of the six automotive assembly plants could be differentiated from the other five assembly plants using Fourier transform infrared spectroscopy (FT-IR), which is the most widely used analytical method for the examination of automotive paint) and the genetic algorithm for pattern recognition. The results of this study indicate that Raman spectroscopy in combination with pattern recognition methods offers distinct advantages over FT-IR for the identification and discrimination of automotive clearcoats.

AlphaMobileSensing: A virtual testbed for mobile environmental monitoring.

Environmental monitoring plays a critical role in creating and maintaining a comfortable, productive, and healthy environment. Built upon the advancements of robotics and data processing, mobile sensing demonstrates its potential to address problems regarding cost, deployment, and resolution that stationary monitoring encounters, which therefore has attracted increasing research attentions recently. To facilitate mobile sensing, two key algorithms are needed: the field reconstruction algorithm and the route planning algorithm. The field reconstruction algorithm is to reconstruct the entire environment field from spatially- and temporally-discrete measurements collected by the mobile sensors. The route planning algorithm is to instruct the mobile sensors where the mobile sensor needs to move to for the next measurements. The performance of mobile sensors highly depends on these two algorithms. However, developing and testing those algorithms in the real world is expensive, challenging, and time-consuming. To address these issues, we proposed and implemented an open-source virtual testbed, AlphaMobileSensing, that can be used to develop, test, and benchmark mobile sensing algorithms. AlphaMobileSensing aims to help users more easily develop and test the field reconstruction and route planning algorithms for mobile sensing solutions, without worrying about hardware fault, test accidents (such as collision during the test), etc. The separation of concerns can significantly reduce the cost of developing software solutions for mobile sensing. For versatility and flexibility, AlphaMobileSensing was wrapped up using the standardized interface of OpenAI Gym, and it also provides an interface for loading physical fields that were generated by numerical simulations as virtual test sites to perform mobile sensing and retrieving monitoring data. We demonstrated applications of the virtual testbed by implementing and testing algorithms for physical field reconstruction in both static and dynamic indoor thermal environments. AlphaMobileSensing provides a novel and flexible platform to develop, test, and benchmark mobile sensing algorithms more easily, conveniently, and efficiently. AlphaMobileSensing is open sourced at https://github.com/kishuqizhou/AlphaMobileSensing. Electronic Supplementary Material ESM: the Appendix is available in the online version of this article at 10.1007/s12273-023-1001-9.

Single-sex schistosomiasis: a mini review.

Schistosomiasis is a neglected tropical disease caused by dioecious blood flukes of the genus Schistosoma and second to malaria as a parasitic disease with significant socio-economic impacts. Mating is essential for maturation of male and female schistosomes and for females to lay of eggs, which are responsible for the pathogenesis and propagation of the life cycle beyond the mammalian host. Single-sex schistosomes, which do not produce viable eggs without mating, have been overlooked given the symptomatic paucity of the single-sex schistosomiasis and limited diagnostic toolkit. Besides, single-sex schistosomes are less sensitive to praziquantel. Therefore, these issues should be considered to achieve the elimination of this infection disease. The aim of this review is to summarize current progress in research of single-sex schistosomes and host-parasite interactions.

Functional characterization of differentially expressed proteins coming from unisexual and bisexual infected Schistosoma japonicum female worms.

Schistosomiasis is an important zoonotic disease affecting up to 40 kinds of animals and is responsible for ∼250 million human cases per year. Due to the extensive use of praziquantel for the treatment of parasitic diseases, drug resistance has been reported. Consequently, novel drugs and effective vaccines are urgently needed for sustained control of schistosomiasis. Targeting reproductive development of Schistosoma japonicum could contribute to the control of schistosomiasis. In this study, five highly expressed proteins (S. japonicum large subunit ribosomal protein L7e, S. japonicum glutathione S-transferase class-mu 26 kDa isozyme, S. japonicum UDP-galactose-4-epimerase and two hypothetical proteins SjCAX70849 and SjCAX72486) in 18, 21, 23, and 25-day mature female worms compared to single-sex infected female worms were selected based on our previous proteomic analysis. Quantitative real-time polymerase chain reaction analysis and long-term interference with small interfering RNA were performed to identify the biological functions of these five proteins. The transcriptional profiles suggested that all five proteins participated in the maturation of S. japonicum. RNA interference against these proteins resulted in morphological changes to S. japonicum. The results of an immunoprotection assay revealed that immunization of mice with recombinant SjUL-30 and SjCAX72486 upregulated production of immunoglobulin G-specific antibodies. Collectively, the results demonstrated that these five differentially expressed proteins were vital to reproduction of S. japonicum and, thus, are potential candidate antigens for immune protection against schistosomiasis.

Comparative proteomic profiles of Schistosoma japonicum male worms derived from single-sex and bisexual infections.

Schistosomiasis, which is caused by parasitic schistosomes, remains the second most prevalent parasitic disease of mammals worldwide. To successfully maintain fecundity, schistosomes have evolved a lifecycle that involves the cooperation of morphologically distinct male and female forms. Eggs produced by worm pairs are vital to the lifecycle of the parasite and are responsible for pathogenesis. Understanding the reproductive mechanism of schistosomes will help to control infection. In this study, the proteomic profiles of single-sex infected male (SM) worms and bisexual infected mated male (MM) worms of Schistosoma japonicum at 18, 21, 23, and 25 days p.i. were identified through data-independent acquisition. In total, 674 differentially expressed proteins (DEPs) were identified for the SM and MM worms at all four timepoints. Bioinformatic analysis demonstrated that most of the DEPs were involved in biosynthetic processes including locomotion, cell growth and death, cell motility, and metabolic processes such as protein metabolism and glucose metabolism. Schistosoma japonicum glycosyltransferase (SjGT) and S. japonicum nicastrin protein (SjNCSTN) were selected for quantitative real­time PCR analysis and long-term interference with small interfering RNA (siRNA) to further explore the functions of the DEPs. Sjgt mRNA expression was mainly enriched in male worms, while Sjncstn was enriched in both sexes. siRNA against SjGT and SjNCSTN resulted in minor morphological changes in the testes of male worms and significant decreased vitality and fertility. The present study provides comprehensive proteomic profiles of S. japonicum SM and MM worms at 18, 21, 23, and 25 days p.i. and offers insights into the mechanisms underlying the growth and maturation of schistosomes.

Multifunctional Roles of MicroRNAs in Schistosomiasis.

Schistosomiasis is a parasitic disease that is caused by helminths of the genus Schistosoma. The dioecious schistosomes mate and lay eggs after undergoing a complex life cycle. Schistosome eggs are mostly responsible for the transmission of schistosomiasis and chronic fibrotic disease induced by egg antigens is the main cause of the high mortality rate. Currently, chemotherapy with praziquantel (PZQ) is the only effective treatment against schistosomiasis, although the potential of drug resistance remains a concern. Hence, there is an urgent demand for new and effective strategies to combat schistosomiasis, which is the second most prevalent parasitic disease after malaria. MicroRNAs (miRNAs) are small non-coding RNAs that play pivotal regulatory roles in many organisms, including the development and sexual maturation of schistosomes. Thus, miRNAs are potential targets for treatment of schistosomiasis. Moreover, miRNAs can serve as multifunctional "nano-tools" for cross-species delivery in order to regulate host-parasite interactions. In this review, the multifunctional roles of miRNAs in the growth and development of schistosomes are discussed. The various regulatory functions of host-derived and worm-derived miRNAs on the progression of schistosomiasis are also thoroughly addressed, especially the promotional and inhibitory effects on schistosome-induced liver fibrosis. Additionally, the potential of miRNAs as biomarkers for the diagnosis and treatment of schistosomiasis is considered.

Schistosoma japonicum translationally controlled tumour protein, which is associated with the development of female worms, as a target for control of schistosomiasis.

Schistosomiasis is a globally important helminthic disease of both humans and animals, and is the second most common parasitic disease after malaria. Although praziquantel is extensively used for treatment of parasitic diseases, drug resistance has been reported. Therefore, new drugs and effective vaccines are needed for continuous control of schistosomiasis. Eggs produced by schistosomes are responsible for the occurrence and spread of schistosomiasis. Revealing the reproductive mechanism of schistosomes will help to control this disease. In this study, the proteomic profiles of single-sex infected female worms and bisexual infected mature female worms of Schistosoma japonicum at 18, 21, 23 and 25 days p.i. were identified with isobaric tags for relative quantitation-coupled liquid chromatography-tandem mass spectrometry. Differentially expressed proteins were subsequently used for bioinformatic analysis. Six highly expressed differentially expressed proteins in mature female worms were selected and long-term interference with small interfering RNA (siRNA) was conducted to determine biological functions. SiRNA against S. japonicum translationally controlled tumour protein (SjTCTP) resulted in the most significant effect on the growth and development of MF worms. Sjtctp mRNA expression gradually increased over time with a high level of expression maintained at 25-42 days p.i., while levels were significantly higher in mature female worms than male and SF worms. The subsequent animal immune protection experiments showed that recombinant SjTCTP (rSjTCTP) reduced the number of adults by 44.7% (P < 0.01), average egg burden per gram of liver by 57.94% (P < 0.01), egg hatching rate by 47.57% (P < 0.01), and oviposition of individual females by 43.16%. rSjTCTP induced higher levels of serum IgG, IL-2, and IL-10 in mice. Collectively, these results show that SjTCTP is vital to reproduction of female worms and, thus, is a candidate antigen for immune protection.

From Inflammation to Fibrosis: Novel Insights into the Roles of High Mobility Group Protein Box 1 in Schistosome-Induced Liver Damage.

Schistosomiasis is a chronic helminthic disease of both humans and animals and the second most prevalent parasitic disease after malaria. Through a complex migration process, schistosome eggs trapped in the liver can lead to the formation of granulomas and subsequent schistosome-induced liver damage, which results in high mortality and morbidity. Although praziquantel can eliminate mature worms and prevent egg deposition, effective drugs to reverse schistosome-induced liver damage are scarce. High mobility group box 1 (HMGB1) is a multifunctional cytokine contributing to liver injury, inflammation, and immune responses in schistosomiasis by binding to cell-surface Toll-like receptors and receptors for advanced glycation end products. HMGB1 is increased in the serum of patients with schistosomiasis and enables hepatic stellate cells to adopt a proliferative myofibroblast-like phenotype, which is crucial to schistosome-induced granuloma formation. Inhibition of HMGB1 was found to generate protective responses against fibrotic diseases in animal models. Clinically, HMGB1 presents a potential target for treatment of the chronic sequelae of schistosomiasis. Here, the pivotal role of HMGB1 in granuloma formation and schistosome-induced liver damage, as well the potential of HMGB1 as a therapeutic target, are discussed.

ClpV1 in avian pathogenic Escherichia coli is a crucial virulence factor contributing to meningitis in a mouse model in vivo.

Meningitis associated with avian pathogenic Escherichia coli (APEC) is an infectious disease of poultry that has gained significant attention because of its potential to infect humans. APEC can utilize two type Ⅵ secretion systems (T6SSs) to efficiently transport toxin effectors into hosts. ClpV1 is one of the core components of the T6SS1. To our knowledge, it has not been clarified how the clpV1 gene contributes to the pathogenicity of meningitis-associated APEC. To investigate the function of the clpV1 gene in the process of Escherichia coli meningitis, a mutant TW-XMΔclpV1 strain was constructed and characterized. In this study, the clpV1 deleted strain displayed a significant decrease in both motility and biofilm formation as well as a reduction in the expression of virulence genes fliC, luxS and ibeA. In vivo studies using mouse and duck models found that the clpV1 deleted groups showed decreased proliferation, fewer lesions and lower expression of inflammatory cytokines in the brain suggesting that clpV1 is involved in the pathogenicity of TWXM. Besides, the decreased quantity of Evans Blue (EB) and the down-regulation of tight junctions (TJs) proteins in the mouse clpV1 deleted group demonstrating a more intact blood-brain barrier (BBB). In conclusion, these results suggest that the clpV1 gene is associated with motility and biofilm formation of TWXM strain and contributes to meningitis by damaging the BBB and brain tissues.

Colibactin in avian pathogenic Escherichia coli contributes to the development of meningitis in a mouse model.

Colibactin is synthesized by a 54-kb genomic island, leads to toxicity in eukaryotic cells, and plays a vital role in many diseases, including neonatal sepsis and meningitis. Avian pathogenic Escherichia coli (APEC) is speculated to be an armory of extraintestinal pathogenic Escherichia coli and can be a potential zoonotic bacterium that threatens human and animal health. In this study, the APEC XM meningitis mouse model was successfully established to investigate the effect of colibactin in in vivo infection. The clbH-deletion mutant strain induced lower γ-H2AX expression, no megalocytosis, and no cell cycle arrest in bEnd.3 cells, which showed that the deletion of clbH decreased the production of colibactin in the APEC XM strain. The deletion of clbH did not affect the APEC XM strain's ability of adhering to and invading bEnd.3 cells. In vitro, the non-colibactin-producing strain displayed significantly lower serum resistance and it also induced a lower level of cytokine mRNA and few disruptions of tight junction proteins in infected bEnd.3 cells. Meningitis did not occur in APEC ΔclbH-infected mice in vivo, who showed fewer clinical symptoms and fewer lesions on radiological and histopathological analyses. Compared with the APEX XM strain, APEC ΔclbH induced lower bacterial colonization in tissues, lower mRNA expression of cytokines in brain tissues, and slight destruction of the brain blood barrier. These results indicate that clbH is a necessary component for the synthesis of genotoxic colibactin, and colibactin is related to the development of meningitis induced by APEC XM.

ClbG in Avian Pathogenic Escherichia coli Contributes to Meningitis Development in a Mouse Model.

Colibactin is a complex secondary metabolite that leads to genotoxicity that interferes with the eukaryotic cell cycle. It plays an important role in many diseases, including neonatal mouse sepsis and meningitis. Avian pathogenic Escherichia coli (APEC) is responsible for several diseases in the poultry industry and may threaten human health due to its potential zoonosis. In this study, we confirmed that clbG was necessary for the APEC XM strain to produce colibactin. The deletion of clbG on APEC XM contributed to lowered γH2AX expression, no megalocytosis, and no cell cycle arrest in vitro. None of the 4-week Institute of Cancer Research mice infected with the APEC XM ΔclbG contracted meningitis or displayed weakened clinical symptoms. Fewer histopathological lesions were observed in the APEC XM ΔclbG group. The bacterial colonization of tissues and the relative expression of cytokines (IL-1ß, IL-6, and TNF-α) in the brains decreased significantly in the APEC XM ΔclbG group compared to those in the APEC XM group. The tight junction proteins (claudin-5, occludin, and ZO-1) were not significantly destroyed in APEC XM ΔclbG group in vivo and in vitro. In conclusion, clbG is necessary for the synthesis of the genotoxin colibactin and affects the development of APEC meningitis in mice.

Transcriptome profiling of avian pathogenic Escherichia coli and the mouse microvascular endothelial cell line bEnd.3 during interaction.

BACKGROUND: Avian pathogenic Escherichia coli (APEC), an important extraintestinal pathogenic E. coli, causes colibacillosis, an acute and mostly systemic disease involving multiple organ lesions such as meningitis. Meningitis-causing APEC can invade the host central nervous system by crossing the blood-brain barrier (BBB), which is a critical step in the development of meningitis. However, the bacteria-host interaction mechanism in this process remains unclear. METHODS: In this study, we examined E. coli and bEnd.3 cells transcriptomes during infection and mock infection to investigate the global transcriptional changes in both organisms using RNA sequencing approach. RESULTS: When APEC infected the bEnd.3 cells, several significant changes in the expression of genes related to cell junctional complexes, extracellular matrix degradation, actin cytoskeleton rearrangement, immune activation and the inflammatory response in bEnd.3 cells were observed as compared to the mock infection group. Thus, the immune activation of bEnd.3 cells indicated that APEC infection activated host defenses. Furthermore, APEC may exploit cell junction degradation to invade the BBB. In addition, amino acid metabolism and energy metabolism related genes were downregulated and the protein export pathway related genes were upregulated in APEC cultured with bEnd.3 cells, compared to that in control. Thus, APEC may encounter starvation and express virulence factors during incubation with bEnd.3 cells. CONCLUSION: This study provides a comprehensive overview of transcriptomic changes that occur during APEC infection of bEnd.3 cells, and offers insights into the bacterial invasion strategies and the subsequent host defense mechanism.

Effects of enzymatically treated Artemisia annua L. on growth performance and some blood parameters of broilers exposed to heat stress.

To evaluate the effects of enzymatically treated Artemisia annua L. (EA) on growth performance and some blood parameters of broilers exposed to heat stress (HS), 320 22-day-old Arbor Acres male broilers were randomly allotted into five groups with eight replicates of eight birds each. Broilers in the control group were housed at 22 ± 1°C and fed the basal diet. Broilers in the HS, HS-EA0.75 , HS-EA1.00 and HS-EA1.25 groups were reared under HS (34 ± 1°C for 8 h/day and 22 ± 1°C for 16 h/day), and fed basal diet with 0, 0.75, 1.00 and 1.25 g/kg EA, respectively. The experiment ended at 42 days. Dietary 1.00 and 1.25 g/kg EA decreased blood pH and elevated body weight gain, feed intake and carcass yield compared to the HS group. Broilers fed EA diets had lower serum concentrations of malondialdehyde and corticosterone and activities of alanine aminotransferase and aspartate aminotransferase, and higher serum total superoxide dismutase activity, tri-iodothyronine concentration and tri-iodothyronine/thyroxine than the HS group. Serum catalase activity in HS-EA1.00 and HS-EA1.25 groups and activity to inhibit hydroxyl in the HS-EA1.00 group were higher than the HS group. In conclusion, dietary 0.75-1.25 g/kg EA addition alleviated HS induced impairments in broilers.