Total Synthesis and Antibacterial Evaluation of Lupinifolin and Its Natural Analogues.

In this study, lupinifolin (1) and its natural analogues, mundulin (2), minimiorin (3), khonklonginol H (4), flemichin D (5), and eriosemaone A (27), were obtained by chemical synthesis for the first time. Key steps involved an electrocyclization to build the linear pyran rings and a Claisen/Cope rearrangement to install the 8-prenyl substituents. All compounds were assessed for their in vitro antimicrobial activities against clinically relevant human pathogens, including one Gram-negative bacterial strain (E. coli ATCC 25922) and four Gram-positive bacterial strains (S. aureus ATCC 29213, E. faecalis ATCC 29212, MRSA21-5, and VRE ATCC 51299). The result indicated that eriosemaone A (27) was the most potent one against Gram-positive bacteria, with minimum inhibitory concentrations in the range of 0.25-0.5 µg/mL. Mechanistic studies indicated that 27 has good membrane-targeting ability to bacterial inner membranes and can bind to phosphatidylglycerol and cardiolipin in bacterial membranes, thereby disrupting the bacterial cell membranes and causing bacterial death.

Total Synthesis of Kuwanons A and B and Discovery of Their Antibacterial Mechanism.

Kuwanons A (1) and B (2) are two natural prenylated flavones isolated from the root bark of Morus alba L. In this study, the first total syntheses of kuwanons A (1) and B (2) were achieved from a common intermediate with overall yields of 6.6% and 11.6%, respectively. Kuwanon B (2) exhibited antibacterial activity against Gram-positive bacteria and concentration-dependent bactericidal activity against Staphylococcus aureus bacteria. Preliminary mechanism of action studies suggested that this compound killed bacteria rapidly by disrupting bacterial membrane integrity.

Total syntheses of pongaflavone and its natural analogues.

The efficient total synthesis of anti-tumor natural product pongaflavone (1) was described starting from commercially available 2,4-dihydroxyacetophenone (9) via seven steps and in 16% overall yield. Its two natural analogues pongachromene (2) and 7,8-(2",2"-dimethylpyrano)-5,3',4'-trihydroxy-3-methoxyflavone (3) were also synthesized following the similar procedure with the yields of 11% and 18%, respectively. Their preliminary anti-tumor activities were evaluated by the inhibition effect on A549 cells. The result showed that this kind of natural products exhibited different levels of anti-tumor activity. Among them, pongachromene (2) displayed the best anti-tumor activity.

Total Syntheses and Anti-inflammatory Evaluations of Pongamosides A-C, Natural Furanoflavonoid Glucosides from Fruit of Pongamia pinnata (L.) Pierre.

The syntheses of three natural furanoflavonoid glucosides, including two flavone glucosides, pongamosides A (1) and B (2), and a flavonol glucoside, pongamoside C (3), were achieved for the first time in 9-15 steps from commercially available materials in overall yields ranging from 2.9% to 29%. The synthetic sequence featured a NaH-promoted BK-VK rearrangement and acid-catalyzed intramolecular cyclization to furnish the furanoflavonoid aglycone. Meanwhile, phase-transfer-catalyzed glycosylation and Schmidt's trichloroacetimidate procedure were employed to establish the pivotal O-glycosidic linkage. The anti-inflammatory activities of compounds 1-3, as well as their aglycones 5a, 5b, and 23, were determined against NO production in the LPS-stimulated RAW264.7 cells. The results indicated that the O-glycosylation may reduce the anti-inflammatory activity of furanoflavonoid in vitro.

Polystyrene nanoplastics exacerbated lipopolysaccharide-induced necroptosis and inflammation via the ROS/MAPK pathway in mice spleen.

Plastics are novel environmental pollutants with potential threats to the ecosystem. At least 5.25 trillion plastic particles in the environment, of which nanoplastics are <100 nm in diameter. Polystyrene nanoplastics (PS-NPs) exposure damaged the spleen's immune function. Lipopolysaccharide (LPS) induced other toxicants to damage cells and organs, triggering inflammation. However, the mechanism of PS-NPs aggravated LPS-induced spleen injury remains unclear. In this study, the PS-NPs or/and LPS mice exposure model was replicated by intraperitoneal injection of PS-NPs or/and LPS, and PS-NPs or/and LPS were exposed to RAW264.7 cells. The histopathological and ultrastructural changes of the mice spleen were observed by H&E staining and transmission electron microscope. Western Blot, qRT-PCR, and fluorescent probes staining were used to detect reactive oxygen species (ROS), oxidative stress indicators, inflammatory factors, and necroptosis-related indicators in mice spleen and RAW264.7 cells. The results showed that PS-NPs or LPS induced oxidative stress, activated the MAPK pathway, and eventually caused necroptosis and inflammation in mice spleen and RAW264.7 cells. Compared with the single treatment group, the changes in PS-NPs + LPS group were more obvious. Furthermore, ROS inhibitor N-Acetyl-L-cysteine (NAC) significantly inhibited the activation of the mitogen-activated protein kinase (MAPK) signaling pathway caused by co-treatment of PS-NPs and LPS, reducing necroptosis and inflammation. The results demonstrated that PS-NPs promoted LPS-induced spleen necroptosis and inflammation in mice through the ROS/MAPK pathway. This study increases the data on the damage of PS-NPs to the organism and expands the research ideas and clues.

First total syntheses of kanjone and its natural analogues.

Kanjone (1), a bioactive furanoflavone and a potent biomolecule, was first isolated from Pongamia pinnata (L.). Herein, we have developed two approaches to synthesize kanjone as well as its natural analogues 6-methoxyisopongaglabol (2) and 6,3'-dimethoxy-[2″,3″:7,8]furanoflavone (3) starting from khellin and 3-hydroxy-4-methoxy-benzaldehyde, respectively.

Total Syntheses and Anti-inflammatory Activities of Syringin and Its Natural Analogues.

Syringin (1), a natural bioactive glucoside isolated from the root of Acanthopanax senticosus (Rupr. Maxim.) Harms, possesses significant anti-inflammatory activity. In this study, we have accomplished the total syntheses of syringin (1), along with its natural analogues 2-12, from a common starting material, syringaldehyde (13), in 4-8 steps with an overall yields of 11.8-61.3%. The anti-inflammatory activities of these compounds were determined against NO production in the LPS-stimulated RAW264.7 cells. Among them, compounds 1-5, 7, and 9 exhibited different levels of anti-inflammatory activity.

Oleanolic acid inhibits the migration and invasion of hepatocellular carcinoma cells by promoting microRNA-122 expression.

MicroRNAs are emerging as important endogenous regulators of gene function and they are playing an important role in the occurrence and development of cancer. They are also regarded as robust biomarkers of cancer diagnosis and prognosis. Hepatocellular carcinoma (HCC) is a common and complex human malignancy with high mortality and morbidity in the world. MicroRNA-122 (miR-122) is a liver-specific microRNA and is closely associated with HCC metastasis, which makes miR-122 a promising target for drug design and development. In this study, we performed a cell-based screening method for discovering miR-122 activators and found that oleanolic acid (OA), a natural pentacyclic triterpene, specifically increased miR-122 expression in a concentration-dependent manner. Two HCC cell lines (HepG2 and Sk-hep-1 cells) were used to evaluate the effect of OA on cell migration and invasion abilities. The results indicated that OA attenuated the migration and invasion abilities of HCC cells by upregulating miR-122 expression. In addition, OA increased the expression of E-cadherin and decreased the expression of ß-catenin, N-cadherin and vimentin. After knocking down miR-122 with miR-122 inhibitor, we found that the effect of OA on these epithelial-to-mesenchymal transition (EMT) related molecules was significantly weakened, indicating OA exhibited anti-EMT effect by increasing the expression of miR-122. These finding may help to better understand the molecular mechanism of OA's anti-metastasis activity.

6-Hydroxy-3-O-methyl-kaempferol 6-O-glucopyranoside potentiates the anti-proliferative effect of interferon α/ß by promoting activation of the JAK/STAT signaling by inhibiting SOCS3 in hepatocellular carcinoma cells.

Suppressor of cytokine signaling 3 (SOCS3) is a key negative regulator of type I interferon (IFN α/ß) signaling. Inhibition of SOCS3 by small molecules may be a new strategy to enhance the efficacy of type I IFN and reduce its side effects. We established a cell-based screening assay using human hepatoma HepG2 cells stably transfected with a plasmid wherein the luciferase reporter activity was propelled by interferon α-stimulated response element (ISRE), which is a motif specifically recognized by type I IFN-induced activation of Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway. After screening our chemical library, 6-hydroxy-3-O-methyl-kaempferol 6-O-glucopyranoside (K6G) was identified to be a potent activator of type I IFN with EC50 value of 3.33±0.04µM. K6G enhanced the phosphorylation of JAK1, Tyk2, and STAT1/2 but decreased the phosphorylation of STAT3. K6G also promoted endogenous IFN-α-regulated genes expression. More interestingly, K6G significantly decreased the expression of SOCS3 without affecting the expression of SOCS1. Furthermore, K6G enhanced the anti-proliferative effect of IFN-α on hepatocellular carcinoma (HCC) cells. These results suggested that K6G potentiated the inhibitory effect of IFN-α on HCC cell proliferation through activation of the JAK/STAT signaling pathway by inhibiting SOCS3 expression. K6G warrants further investigation as a novel therapeutic method to enhance the efficacy of IFN-α/ß.

Differential Expression of Adenosine P1 Receptor ADORA1 and ADORA2A Associated with Glioma Development and Tumor-Associated Epilepsy.

Level of adenosine, an endogenous astrocyte-based neuromodulator, is primarily regulated by adenosine P1 receptors. This study assessed expression of adenosine P1 receptors, ADORA1 (adenosine A1 receptor) and ADORA2A (adenosine A2a receptor) and their association with glioma development and epilepsy in glioma patients. Expression of ADORA1/ADORA2A was assessed immunohistochemically in 65 surgically removed glioma tissue and 21 peri-tumor tissues and 8 cases of normal brain tissues obtained from hematoma patients with cerebral trauma. Immunofluorescence, Western blot, and qRT-PCR were also used to verify immunohistochemical data. Adenosine P1 receptor ADORA1 and ADORA2A proteins were localized in the cell membrane and cytoplasm and ADORA1/ADORA2A immunoreactivity was significantly stronger in glioma and peri-tumor tissues that contained infiltrating tumor cells than in normal brain tissues (p < 0.05). The World Health Organization (WHO) grade III gliomas expressed even higher level of ADORA1 and ADORA2A. Western blot and qRT-PCR confirmed immunohistochemical data. Moreover, higher levels of ADORA1 and ADORA2A expression occurred in high-grade gliomas, in which incidence of epilepsy were lower (p < 0.05). In contrast, a lower level of ADORA1/ADORA2A expression was found in peri-tumor tissues with tumor cell presence from patients with epilepsy compared to patients without epilepsy (p < 0.05). The data from the current study indicates that dysregulation in ADORA1/ADORA2A expression was associated with glioma development, whereas low level of ADORA1/ADORA2A expression could increase susceptibility of tumor-associated epilepsy.

Ser9-phosphorylated GSK3ß induced by 14-3-3ζ actively antagonizes cell apoptosis in a NF-κB dependent manner.

The activity of glycogen synthase kinase beta (GSK3ß) is mainly regulated by its Ser9 phosphorylation. It has been believed for a long time that Ser9 phosphorylation regulates the functions of GSK3ß through inhibition of its kinase activity. In this study, we have confirmed the interaction of Ser9-phosphorylated GSK3ß with 14-3-3ζ by using GST pull-down assays. We show that 14-3-3ζ enhances Ser9 phosphorylation of GSK3ß by PKC. Surprisingly, using a NF-κB luciferase reporter system, we find that Ser9-phosphorylation of GSK3ß promoted by 14-3-3ζ is critical for the activation of NF-κB pathway, which may thwart the pro-apoptotic activity of GSK3ß. Inhibition of either NF-κB or GSK3ß significantly abolishes the anti-apoptotic effect of 14-3-3ζ and Ser9-phosphorylated GSK3ß, suggesting that Ser9-phosphorylated GSK3ß actively antagonizes cell apoptosis in a NF-κB dependent manner.

L-arginine alleviates heat stress-induced mammary gland injury through modulating CASTOR1-mTORC1 axis mediated mitochondrial homeostasis.

As global warming intensifies, extreme heat is becoming increasingly frequent. These extreme heatwaves have decreased the milk production of dairy animals such as cows and goats and have caused significant damage to the entire dairy industry. It is known that heat stress (HS) can induce the apoptosis and autophagy of mammary epithelial cells (MECs), leading to a decrease in lactating MECs. L-arginine can effectively attenuate HS-induced decreases in milk yield, but the exact mechanisms are not fully understood. In this study, we found that HS upregulated the arginine sensor CASTOR1 in mouse MECs. Arginine activated mTORC1 activity through CASTOR1 and promoted mitochondrial biogenesis through the mTORC1/PGC-1α/NRF1 pathway. Moreover, arginine inhibited mitophagy through the CASTOR1/PINK1/Parkin pathway. Mitochondrial homeostasis ensures ATP synthesis and a stable cellular redox state for MECs under HS, further alleviating HS-induced damage and improving the lactation performance of MECs. In conclusion, these findings reveal the molecular mechanisms by which L-arginine relieves HS-induced mammary gland injury, and suggest that the intake of arginine-based feeds or feed additives is a promising method to increase the milk yield of dairy animals in extreme heat conditions.

A Transcriptomic and Metabolomic Study on the Biosynthesis of Iridoids in Phlomoides rotata from the Qinghai-Tibet Plateau.

Phlomoides rotata is a traditional Chinese herbal medicine that grows in the Qinghai-Tibet Plateau region at a 3100-5000 m altitude. Iridoid compounds are the main active compounds of the P. rotata used as medical ingredients and display anti-inflammatory, analgesic, and hepatoprotective properties. To better understand the biological mechanisms of iridoid compounds in this species, we performed a comprehensive analysis of the transcriptome and metabolome of P. rotata leaves from four different regions (3540-4270 m). Global metabolome profiling detected 575 metabolites, and 455 differentially accumulated metabolites (DAMs) were detected in P. rotata leaves from the four regions. Eight major DAMs related to iridoid metabolism in P. rotata leaves were investigated: shanzhiside methyl ester, 8-epideoxyloganic acid, barlerin, shanzhiside, geniposide, agnuside, feretoside, and catalpin. In addition, five soil physical and chemical indicators in P. rotata rhizosphere soils were analyzed. Four significant positive correlations were observed between alkaline nitrogen and geniposide, exchangeable calcium and geniposide, available potassium and shanzhiside, and available phosphorus and shanzhiside methyl ester. The transcriptome data showed 12 P. rotata cDNA libraries with 74.46 Gb of clean data, which formed 29,833 unigenes. Moreover, 78.91% of the unigenes were annotated using the eight public databases. Forty-one candidate genes representing 23 enzymes involved in the biosynthesis of iridoid compounds were identified in P. rotata leaves. Moreover, the DXS1, IDI1, 8-HGO1, and G10H2 genes associated with iridoid biosynthesis were specifically expressed in P. rotata. The integration of transcriptome and metabolome analyses highlights the crucial role of soil physical and chemical indicators and major gene expression related to iridoid metabolism pathways in P. rotata from different areas. Our findings provide a theoretical foundation for exploring the molecular mechanisms underlying iridoid compound accumulation in P. rotata.

Dietary selenomethionine reduced oxidative stress by resisting METTL3-mediated m6A methylation level of Nrf2 to ameliorate LPS-induced liver necroptosis in laying hens.

Selenomethionine (SeMet) as the main form of daily dietary selenium, occupies essential roles in providing antioxidant and anti-inflammatory properties, which alleviates inflammatory liver damage. N6-methyladenosine (m6A) is one of the most prevalent and abundant internal transcriptional modifications that regulate gene expression. To investigate the protective mechanism of SeMet on liver injury and the regulatory effect of m6A methylation modification, we established the model by supplementing dietary SeMet, and LPS as stimulus in laying hens. LMH cells were intervened with SeMet (0.075 µM) and/or LPS (60 µg/mL). Subsequently, histopathology and ultrastructure of liver were observed. Western Blot, qRT-PCR, colorimetry, MeRIP-qPCR, fluorescent probe staining and AO/EB were used to detect total m6A methylation level, m6A methylation level of Nrf2, ROS, inflammatory and necroptosis factors. Studies showed that SeMet suppressed LPS-induced upregulation of total m6A methylation levels and METTL3 expression. Interestingly, SeMet reduced the m6A methylation level of Nrf2, activated antioxidant pathways and alleviated oxidative stress. LMH cells were transfected with 50 µm siMETTL3. SeMet/SiMETTL3 reversed the LPS-induced reduction in Nrf2 mRNA stability, slowed down its degradation rate. Moreover, LPS induced oxidative stress, led to necroptosis and activated NF-κB to promote the expression of inflammatory factors. SeMet/SiMETTL3 alleviated LPS-induced necroptosis and inflammation. Altogether, SeMet enhanced antioxidant and anti-inflammatory capacity by reducing METTL3-mediated m6A methylation levels of Nrf2, ultimately alleviating liver damage. Our findings provided new insights and therapeutic target for the practical application of dietary SeMet in the treatment and prevention of liver inflammation, and supplied a reference for comparative medicine.

Selenium deficiency exacerbated Bisphenol A-induced intestinal toxicity in chickens: Apoptosis and cell cycle arrest mediated by ROS/P53.

Bisphenol A (BPA) is a phenolic organic synthetic compound that is used as the raw material of polycarbonate plastics, and its safety issues have recently attracted wide attention. Selenium (Se) deficiency has gradually developed into a global disease affecting intestinal function via oxidative stress and apoptosis. However, the toxic effects and potential mechanisms of BPA exposure and Se deficiency in the chicken intestines have not been studied. In this study, BPA exposure and/or Se deficiency models were established in vivo and in vitro to investigate the effects of Se deficiency and BPA on chicken jejunum. The results showed that BPA exposure and/or Se deficiency increased jejunum oxidative stress and DNA damage, activated P53 pathway, led to mitochondrial dysfunction, and induced apoptosis and cell cycle arrest. Using protein-protein molecular docking, we found a strong binding ability between P53 and peroxisome proliferator-activated receptor γ coactivator-1, thereby regulating mitochondrial dysfunctional apoptosis. In addition, we used N-acetyl-L-cysteine and pifithrin-α for in vitro intervention and found that N-acetyl-L-cysteine and pifithrin-α intervention reversed the aforementioned adverse effects. This study clarified the potential mechanism by which Se deficiency exacerbates BPA induced intestinal injury in chickens through reactive oxygen species/P53, which provides a new idea for the study of environmental combined toxicity of Se deficiency, and insights into animal intestinal health from a new perspective.

Selenium Deficiency Induces Inflammatory Response and Decreased Antimicrobial Peptide Expression in Chicken Jejunum Through Oxidative Stress.

Selenium deficiency can affect the level of selenoprotein in organs and tissues and cause inflammation. However, the mechanism of selenium deficiency on jejunal injury in chickens remains unclear. In this study, we established a selenium deficiency model in chickens by feeding a low selenium diet and observed ultrastructural and pathological changes in the jejunum. The expression levels of 25 selenoproteins, the levels of oxidative stress, tight junction (TJ) proteins, and antimicrobial peptides (AMP), as well as the expression levels of factors related to inflammatory signaling pathways, were examined in the intestine and analyzed using principal component analysis (PCA). The results of PCA and quantitative real-time PCR (qRT-PCR) showed that selenium deficiency mainly affected the expression of antioxidant selenoproteins in chicken jejunum, especially glutathione peroxidases, thioredoxin reductase, and iodothyronine deiodinase, thus weakening the antioxidant function in the intestine and inducing oxidative stress. We also found disruption of intestinal TJ structures, a significant reduction in TJ protein expression, and downregulation of antimicrobial peptide levels, suggesting that selenium deficiency led to damage of the intestinal barrier. In addition, a significant increase in inflammatory cell infiltration and expression of inflammatory factors was observed in the jejunum, indicating that selenium deficiency induces inflammatory injury. In conclusion, selenium deficiency downregulates antioxidant selenoproteins levels, induces oxidative stress, decreases intestinal AMP levels, and leads to inflammatory injury and disruption of the intestinal barrier in the jejunum. These results shed new light on the molecular mechanisms of intestinal damage caused by selenium deficiency.

Mapping of the AgWp1 gene for the white petiole in celery (Apium graveolens L.).

Celery (Apium graveolens L.) is one of the most popular leafy vegetables worldwide. The main edible parts of celery are the leaf blade and especially the petiole, which typically has a white, green and red color. To date, there are very few reports about the inheritance and gene cloning of celery petiole color. In this study, bulked segregant analysis-sequencing (BSA-Seq) and fine mapping were conducted to delimit the white petiole (wp1) loci into a 668.5-kb region on Chr04. In this region, AgWp1 is a homolog of a DAG protein in Antirrhinum majus and a MORF9 protein in Arabidopsis, and both proteins are involved in chloroplast development. Sequencing alignment shows that there is a 27-bp insertion in the 3'-utr region in AgWp1 in the white petiole. Gene expression analysis indicated that the expression level of AgWp1 in the green petiole was much higher than that in the white petiole. Further cosegregation revealed that the 27-bp insertion was completely cosegregated with the petiole color in 45 observed celery varieties. Therefore, AgWp1 was considered to be the candidate gene controlling the white petiole in celery. Our results could not only improve the efficiency and accuracy of celery breeding but also help in understanding the mechanism of chlorophyll synthesis and chloroplast development in celery.

PRMT1 reverts the immune escape of necroptotic colon cancer through RIP3 methylation.

Necroptosis plays a double-edged sword role in necroptotic cancer cell death and tumor immune escape. How cancer orchestrates necroptosis with immune escape and tumor progression remains largely unclear. We found that RIP3, the central activator of necroptosis, was methylated by PRMT1 methyltransferase at the amino acid of RIP3 R486 in human and the conserved amino acid R479 in mouse. The methylation of RIP3 by PRMT1 inhibited the interaction of RIP3 with RIP1 to suppress RIP1-RIP3 necrosome complex, thereby blocking RIP3 phosphorylation and necroptosis activation. Moreover, the methylation-deficiency RIP3 mutant promoted necroptosis, immune escape and colon cancer progression due to increasing tumor infiltrated myeloid-derived immune suppressor cells (MDSC), while PRMT1 reverted the immune escape of RIP3 necroptotic colon cancer. Importantly, we generated a RIP3 R486 di-methylation specific antibody (RIP3ADMA). Clinical patient samples analysis revealed that the protein levels of PRMT1 and RIP3ADMA were positively correlated in cancer tissues and both of them predicted the longer patient survival. Our study provides insights into the molecular mechanism of PRMT1-mediated RIP3 methylation in the regulation of necroptosis and colon cancer immunity, as well as reveals PRMT1 and RIP3ADMA as the valuable prognosis markers of colon cancer.

Polystyrene nanoparticle exposure supports ROS-NLRP3 axis-dependent DNA-NET to promote liver inflammation.

The widespread use of plastics and the rapid development of nanotechnology bring convenience to our lives while also increasing the environmental burden and increasing the risk of exposure of organisms to nanoparticles (NPs). While recent studies have revealed an association between nanoparticles and liver injury, the intrinsic mechanism of NP exposure-induced liver damage remains to be explored. Here, we found that polystyrene nanoparticle (PSNP) exposure resulted in a significant increase in local neutrophil infiltration and neutrophil extracellular trap (NET) formation in the liver. Analysis of a coculture system of PBNs and AML12 cells revealed that PSNP-induced NET formation positively correlates with the reactive oxygen species (ROS)-NLRP3 axis. Inhibition of ROS and genetic and pharmacological inhibition of NLRP3 in AML12 can both alleviate PSNP-induced NET formation. In turn, exposure of mice to deoxyribonuclease I (DNase Ⅰ)-coated PSNPs disassembled NET in vivo, neutrophil infiltration in the liver was reduced, the ROS-NLRP3 axis was inhibited, and the expression of cytokines was markedly decreased. Collectively, our work reveals a mechanism of NET formation in PSNP exposure-induced liver inflammation and highlights the possible role of DNase Ⅰ as a key enzyme in degrading NET and alleviating liver inflammation.

Regulating of LncRNA2264/miR-20b-5p/IL17RD axis on hydrogen sulfide exposure-induced inflammation in broiler thymus by activating MYD88/NF-κB pathway.

Hydrogen sulfide (H2S) is an environmental pollutant. Chronic exposure to H2S can damage the immune system of birds, but the detailed mechanisms of H2S-induced thymus toxicity have not been determined. Competitive endogenous RNA (ceRNA) mechanism participates in many pathophysiological processes by regulating gene expression, including environmental pollutant-induced injury. Therefore, we investigate the specific mechanisms of ceRNA in the process of H2S-induced thymic immune damage in broiler chickens. In the current study, 120 one-day-old male Ross 308 broilers were randomly divided into two groups (n = 60 chickens/group), raising in the control chamber (0.5 ± 0.5 ppm) or H2S-exposed chamber (4.0 ± 0.5 ppm at 0-3 weeks of age and 20.0 ± 0.5 ppm at 4-6 weeks of age groups) to replicate the H2S-exposed broilers. NaHS (3 mM or 6 mM) was used to treat chicken macrophages (HD11) to establish an in vitro. Histopathology and ultrastructural changes of thymus were assessed by hematoxylin and eosin (H&E) staining and transmission electron microscopy (TEM). Gene expression profiles were analyzed by using transcriptomics. The underlying mechanisms of thymic injury were further revealed by dual luciferase reporter gene assay, qRT-PCR and Western blotting. Research results showed that H2S exposure induced an inflammatory response in thymus, with the expression of LncRNA2264 was significantly down-regulated. LncRNA2264 could competitively bind to miR-20b-5p and caused downregulation of the IL17RD. H2S could activate inflammatory factors through the LncRNA2264/miR-20b-5p/IL17RD axis. In summary, this study suggested that LncRNA2264 acted as a miR-20b-5p molecular sponge to regulate the expression of IL17RD involved in H2S exposure-induced thymic inflammation, which has positive implications for guiding the prevention and control of H2S gas poisoning in livestock housing and ensuring animal welfare.