1.In situ Analytical Techniques for Membrane Protein Interactions
Zi-Yuan KANG ; Tong YU ; Chao LI ; Xue-Hua ZHANG ; Jun-Hui GUO ; Qi-Chang LI ; Jing-Xing GUO ; Hao XIE
Progress in Biochemistry and Biophysics 2025;52(5):1206-1218
Membrane proteins are integral components of cellular membranes, accounting for approximately 30% of the mammalian proteome and serving as targets for 60% of FDA-approved drugs. They are critical to both physiological functions and disease mechanisms. Their functional protein-protein interactions form the basis for many physiological processes, such as signal transduction, material transport, and cell communication. Membrane protein interactions are characterized by membrane environment dependence, spatial asymmetry, weak interaction strength, high dynamics, and a variety of interaction sites. Therefore, in situ analysis is essential for revealing the structural basis and kinetics of these proteins. This paper introduces currently available in situ analytical techniques for studying membrane protein interactions and evaluates the characteristics of each. These techniques are divided into two categories: label-based techniques (e.g., co-immunoprecipitation, proximity ligation assay, bimolecular fluorescence complementation, resonance energy transfer, and proximity labeling) and label-free techniques (e.g., cryo-electron tomography, in situ cross-linking mass spectrometry, Raman spectroscopy, electron paramagnetic resonance, nuclear magnetic resonance, and structure prediction tools). Each technique is critically assessed in terms of its historical development, strengths, and limitations. Based on the authors’ relevant research, the paper further discusses the key issues and trends in the application of these techniques, providing valuable references for the field of membrane protein research. Label-based techniques rely on molecular tags or antibodies to detect proximity or interactions, offering high specificity and adaptability for dynamic studies. For instance, proximity ligation assay combines the specificity of antibodies with the sensitivity of PCR amplification, while proximity labeling enables spatial mapping of interactomes. Conversely, label-free techniques, such as cryo-electron tomography, provide near-native structural insights, and Raman spectroscopy directly probes molecular interactions without perturbing the membrane environment. Despite advancements, these methods face several universal challenges: (1) indirect detection, relying on proximity or tagged proxies rather than direct interaction measurement; (2) limited capacity for continuous dynamic monitoring in live cells; and (3) potential artificial influences introduced by labeling or sample preparation, which may alter native conformations. Emerging trends emphasize the multimodal integration of complementary techniques to overcome individual limitations. For example, combining in situ cross-linking mass spectrometry with proximity labeling enhances both spatial resolution and interaction coverage, enabling high-throughput subcellular interactome mapping. Similarly, coupling fluorescence resonance energy transfer with nuclear magnetic resonance and artificial intelligence (AI) simulations integrates dynamic structural data, atomic-level details, and predictive modeling for holistic insights. Advances in AI, exemplified by AlphaFold’s ability to predict interaction interfaces, further augment experimental data, accelerating structure-function analyses. Future developments in cryo-electron microscopy, super-resolution imaging, and machine learning are poised to refine spatiotemporal resolution and scalability. In conclusion, in situ analysis of membrane protein interactions remains indispensable for deciphering their roles in health and disease. While current technologies have significantly advanced our understanding, persistent gaps highlight the need for innovative, integrative approaches. By synergizing experimental and computational tools, researchers can achieve multiscale, real-time, and perturbation-free analyses, ultimately unraveling the dynamic complexity of membrane protein networks and driving therapeutic discovery.
2.Conserved translational control in cardiac hypertrophy revealed by ribosome profiling.
Bao-Sen WANG ; Jian LYU ; Hong-Chao ZHAN ; Yu FANG ; Qiu-Xiao GUO ; Jun-Mei WANG ; Jia-Jie LI ; An-Qi XU ; Xiao MA ; Ning-Ning GUO ; Hong LI ; Zhi-Hua WANG
Acta Physiologica Sinica 2025;77(5):757-774
A primary hallmark of pathological cardiac hypertrophy is excess protein synthesis due to enhanced translational activity. However, regulatory mechanisms at the translational level under cardiac stress remain poorly understood. Here we examined the translational regulations in a mouse cardiac hypertrophy model induced by transaortic constriction (TAC) and explored the conservative networks versus the translatome pattern in human dilated cardiomyopathy (DCM). The results showed that the heart weight to body weight ratio was significantly elevated, and the ejection fraction and fractional shortening significantly decreased 8 weeks after TAC. Puromycin incorporation assay showed that TAC significantly increased protein synthesis rate in the left ventricle. RNA-seq revealed 1,632 differentially expressed genes showing functional enrichment in pathways including extracellular matrix remodeling, metabolic processes, and signaling cascades associated with pathological cardiomyocyte growth. When combined with ribosome profiling analysis, we revealed that translation efficiency (TE) of 1,495 genes was enhanced, while the TE of 933 genes was inhibited following TAC. In DCM patients, 1,354 genes were upregulated versus 1,213 genes were downregulated at the translation level. Although the majority of the genes were not shared between mouse and human, we identified 93 genes, including Nos3, Kcnj8, Adcy4, Itpr1, Fasn, Scd1, etc., with highly conserved translational regulations. These genes were remarkably associated with myocardial function, signal transduction, and energy metabolism, particularly related to cGMP-PKG signaling and fatty acid metabolism. Motif analysis revealed enriched regulatory elements in the 5' untranslated regions (5'UTRs) of transcripts with differential TE, which exhibited strong cross-species sequence conservation. Our study revealed novel regulatory mechanisms at the translational level in cardiac hypertrophy and identified conserved translation-sensitive targets with potential applications to treat cardiac hypertrophy and heart failure in the clinic.
Animals
;
Humans
;
Cardiomegaly/physiopathology*
;
Ribosomes/physiology*
;
Protein Biosynthesis/physiology*
;
Mice
;
Cardiomyopathy, Dilated/genetics*
;
Ribosome Profiling
3.UPLC-Q-TOF-MS combined with network pharmacology reveals effect and mechanism of Gentianella turkestanorum total extract in ameliorating non-alcoholic steatohepatitis.
Wu DAI ; Dong-Xuan ZHENG ; Ruo-Yu GENG ; Li-Mei WEN ; Bo-Wei JU ; Qiang HOU ; Ya-Li GUO ; Xiang GAO ; Jun-Ping HU ; Jian-Hua YANG
China Journal of Chinese Materia Medica 2025;50(7):1938-1948
This study aims to reveal the effect and mechanism of Gentianella turkestanorum total extract(GTI) in ameliorating non-alcoholic steatohepatitis(NASH). UPLC-Q-TOF-MS was employed to identify the chemical components in GTI. SwissTarget-Prediction, GeneCards, OMIM, and TTD were utilized to screen the targets of GTI components and NASH. The common targets shared by GTI components and NASH were filtered through the STRING database and Cytoscape 3.9.0 to identify core targets, followed by GO and KEGG enrichment analysis. AutoDock was used for molecular docking of key components with core targets. A mouse model of NASH was established with a methionine-choline-deficient high-fat diet. A 4-week drug intervention was conducted, during which mouse weight was monitored, and the liver-to-brain ratio was measured at the end. Hematoxylin-eosin staining, Sirius red staining, and oil red O staining were employed to observe the pathological changes in the liver tissue. The levels of various biomarkers, including aspartate aminotransferase(AST), alanine aminotransferase(ALT), hydroxyproline(HYP), total cholesterol(TC), triglycerides(TG), low-density lipoprotein cholesterol(LDL-C), high-density lipoprotein cholesterol(HDL-C), malondialdehyde(MDA), superoxide dismutase(SOD), and glutathione(GSH), in the serum and liver tissue were determined. RT-qPCR was conducted to measure the mRNA levels of interleukin 1β(IL-1β), interleukin 6(IL-6), tumor necrosis factor α(TNF-α), collagen type I α1 chain(COL1A1), and α-smooth muscle actin(α-SMA). Western blotting was conducted to determine the protein levels of IL-1β, IL-6, TNF-α, and potential drug targets identified through network pharmacology. UPLC-Q-TOF/MS identified 581 chemical components of GTI, and 534 targets of GTI and 1 157 targets of NASH were screened out. The topological analysis of the common targets shared by GTI and NASH identified core targets such as IL-1β, IL-6, protein kinase B(AKT), TNF, and peroxisome proliferator activated receptor gamma(PPARG). GO and KEGG analyses indicated that the ameliorating effect of GTI on NASH was related to inflammatory responses and the phosphoinositide 3-kinase(PI3K)/AKT pathway. The staining results demonstrated that GTI ameliorated hepatocyte vacuolation, swelling, ballooning, and lipid accumulation in NASH mice. Compared with the model group, high doses of GTI reduced the AST, ALT, HYP, TC, and TG levels(P<0.01) while increasing the HDL-C, SOD, and GSH levels(P<0.01). RT-qPCR results showed that GTI down-regulated the mRNA levels of IL-1β, IL-6, TNF-α, COL1A1, and α-SMA(P<0.01). Western blot results indicated that GTI down-regulated the protein levels of IL-1β, IL-6, TNF-α, phosphorylated PI3K(p-PI3K), phosphorylated AKT(p-AKT), phosphorylated inhibitor of nuclear factor kappa B alpha(p-IκBα), and nuclear factor kappa B(NF-κB)(P<0.01). In summary, GTI ameliorates inflammation, dyslipidemia, and oxidative stress associated with NASH by regulating the PI3K/AKT/NF-κB signaling pathway.
Animals
;
Non-alcoholic Fatty Liver Disease/genetics*
;
Mice
;
Network Pharmacology
;
Male
;
Drugs, Chinese Herbal/administration & dosage*
;
Chromatography, High Pressure Liquid
;
Liver/metabolism*
;
Mice, Inbred C57BL
;
Humans
;
Mass Spectrometry
;
Tumor Necrosis Factor-alpha/metabolism*
;
Disease Models, Animal
;
Molecular Docking Simulation
4.Randomized, double-blind, parallel-controlled, multicenter, equivalence clinical trial of Jiuwei Xifeng Granules(Os Draconis replaced by Ostreae Concha) for treating tic disorder in children.
Qiu-Han CAI ; Cheng-Liang ZHONG ; Si-Yuan HU ; Xin-Min LI ; Zhi-Chun XU ; Hui CHEN ; Ying HUA ; Jun-Hong WANG ; Ji-Hong TANG ; Bing-Xiang MA ; Xiu-Xia WANG ; Ai-Zhen WANG ; Meng-Qing WANG ; Wei ZHANG ; Chun WANG ; Yi-Qun TENG ; Yi-Hui SHAN ; Sheng-Xuan GUO
China Journal of Chinese Materia Medica 2025;50(6):1699-1705
Jiuwei Xifeng Granules have become a Chinese patent medicine in the market. Because the formula contains Os Draconis, a top-level protected fossil of ancient organisms, the formula was to be improved by replacing Os Draconis with Ostreae Concha. To evaluate whether the improved formula has the same effectiveness and safety as the original formula, a randomized, double-blind, parallel-controlled, equivalence clinical trial was conducted. This study enrolled 288 tic disorder(TD) of children and assigned them into two groups in 1∶1. The treatment group and control group took the modified formula and original formula, respectively. The treatment lasted for 6 weeks, and follow-up visits were conducted at weeks 2, 4, and 6. The primary efficacy endpoint was the difference in Yale global tic severity scale(YGTSS)-total tic severity(TTS) score from baseline after 6 weeks of treatment. The results showed that after 6 weeks of treatment, the declines in YGTSS-TSS score showed no statistically significant difference between the two groups. The difference in YGTSS-TSS score(treatment group-control group) and the 95%CI of the full analysis set(FAS) were-0.17[-1.42, 1.08] and those of per-protocol set(PPS) were 0.29[-0.97, 1.56], which were within the equivalence boundary [-3, 3]. The equivalence test was therefore concluded. The two groups showed no significant differences in the secondary efficacy endpoints of effective rate for TD, total score and factor scores of YGTSS, clinical global impressions-severity(CGI-S) score, traditional Chinese medicine(TCM) response rate, or symptom disappearance rate, and thus a complete evidence chain with the primary outcome was formed. A total of 6 adverse reactions were reported, including 4(2.82%) cases in the treatment group and 2(1.41%) cases in the control group, which showed no statistically significant difference between the two groups. No serious suspected unexpected adverse reactions were reported, and no laboratory test results indicated serious clinically significant abnormalities. The results support the replacement of Os Draconis by Ostreae Concha in the original formula, and the efficacy and safety of the modified formula are consistent with those of the original formula.
Adolescent
;
Child
;
Child, Preschool
;
Female
;
Humans
;
Male
;
Double-Blind Method
;
Drugs, Chinese Herbal/therapeutic use*
;
Tic Disorders/drug therapy*
;
Treatment Outcome
5.Analysis of impact of host plants on quality of Taxilli Herba based on widely targeted metabolomics.
Dong-Lan ZHOU ; Zi-Shu CHAI ; Mei RU ; Fei-Ying HUANG ; Xie-Jun ZHANG ; Min GUO ; Yong-Hua LI
China Journal of Chinese Materia Medica 2025;50(12):3281-3290
This study aims to explore the impact of host plants on the quality of Taxilli Herba and provide a theoretical basis for the quality control of Taxilli Herba. The components of Taxilli Herba from three different host plants(Morus alba, Salix babylonica, and Cinnamomum cassia) and its 3 hosts(mulberry branch, willow branch, and cinnamon branch) were detected by widely targeted metabolomics based on ultra-high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS). Principal component analysis(PCA), orthogonal partial least squares discriminant analysis(OPLS-DA), and Venn diagram were employed for analysis. A total of 717 metabolites were detected in Taxilli Herba from the three host plants and the branches of these host plants by UPLC-MS/MS. The results of PCA and OPLS-DA of Taxilli Herba from the three different host plants showed an obvious separation trend due to the different effects of host plants. The Venn diagram showed that there were 32, 8, and 26 characteristic metabolites in samples of Taxilli Herba from M. alba host, S. babylonica host, and C. cassia host, respectively. It was found by comparing the characteristic metabolites of Taxilli Herba and its hosts that each host transmits its characteristic components to Taxilli Herba, so that the Taxilli Herba contains the characteristic components of the host. The Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway analysis showed that the differential metabolites of Taxilli Herba from the three hosts were mainly enriched in flavonoid biosynthesis, arginine and proline metabolism, and glycolysis/gluconeogenesis pathways. Furthermore, the differential metabolites enriching pathways of Taxilli Herba from the three hosts were different depending on the host. In a word, host plants have a significant impact on the metabolites of Taxilli Herba, and it may be an important factor for the quality of Taxilli Herba.
Metabolomics/methods*
;
Drugs, Chinese Herbal/chemistry*
;
Chromatography, High Pressure Liquid
;
Tandem Mass Spectrometry
;
Quality Control
;
Salix/chemistry*
;
Cinnamomum aromaticum/metabolism*
;
Principal Component Analysis
6.Tetrahydropalmatine acts on α7nAChR to regulate inflammation and polarization of BV2 microglia.
Yan-Jun WANG ; Guo-Liang DAI ; Pei-Yao CHEN ; Hua-Xi HANG ; Xin-Fang BIAN ; Yu-Jie CHEN ; Wen-Zheng JU
China Journal of Chinese Materia Medica 2025;50(11):3117-3126
Based on the α7 nicotinic acetylcholine receptor(α7nAChR), this study examined how tetrahydropalmatine(THP) affected BV2 microglia exposed to lipopolysaccharide(LPS), aiming to clarify the possible mechanism underlying the anti-depression effect of THP from the perspectives of preventing inflammation and regulating polarization. First, after molecular docking and determination of the content of Corydalis saxicola Bunting total alkaloids, THP was initially identified as a possible anti-depression component. The BV2 microglia model of inflammation was established with LPS. BV2 microglia were allocated into a normal group, a model group, low-and high-dose(20 and 40 μmol·L~(-1), respectively) THP groups, and a THP(20 μmol·L~(-1))+α7nAChR-specific antagonist MLA(1 μmol·L~(-1)) group. The CCK-8 assay was used to screen the safe concentration of THP. A light microscope was used to examine the morphology of the cells. Western blot and immunofluorescence were used to determine the expression of α7nAChR. qRT-PCR was performed to determine the mRNA levels of inducible nitric oxide synthase(iNOS), cluster of differentiation 86(CD86), suppressor of cytokine signaling 3(SOCS3), arginase-1(Arg-1), cluster of differentiation 206(CD206), tumor necrosis factor(TNF)-α, interleukin(IL)-6, and IL-1β. Enzyme-linked immunosorbent assay(ELISA) was employed to measure the levels of TNF-α, IL-6, and IL-1β in the cell supernatant. The experimental results showed that THP at concentrations of 40 μmol·L~(-1) and below had no effect on BV2 microglia. THP improved the morphology of BV2 microglia, significantly up-regulated the protein level of α7nAChR, significantly down-regulated the mRNA levels of iNOS, CD86, SOCS3, TNF-α, IL-6, and IL-1β, significantly up-regulated the mRNA levels of Arg-1 and CD206, and dramatically lowered the levels of TNF-α, IL-6, and IL-1β in the cell supernatant. However, the antagonist MLA abolished the above-mentioned ameliorative effects of THP on LPS-treated BV2 microglia. As demonstrated by the aforementioned findings, THP protected LPS-treated BV2 microglia by regulating the M1/M2 polarization and preventing inflammation, which might be connected to the regulation of α7nAChR on BV2 microglia.
Berberine Alkaloids/chemistry*
;
alpha7 Nicotinic Acetylcholine Receptor/chemistry*
;
Microglia/metabolism*
;
Mice
;
Animals
;
Cell Line
;
Corydalis/chemistry*
;
Humans
;
Molecular Docking Simulation
;
Inflammation/drug therapy*
;
Nitric Oxide Synthase Type II/immunology*
;
Tumor Necrosis Factor-alpha/immunology*
7.Clinical effects of single Kirschner wire assisted reduction in children with Gartland type Ⅲ supracondylar humerus fractures.
Yong HE ; Wei-Ping LI ; Zhi-Long CHEN ; Guo-Peng JIANG ; Shi-Hai CHEN ; Jun ZHAO ; Hua-Ming WANG ; Chen ZHANG
China Journal of Orthopaedics and Traumatology 2025;38(10):1071-1075
OBJECTIVE:
To investigate the clinical efficacy and safety of single Kirschner wire assisted poking and closed reduction in the treatment of Gartland type Ⅲ supracondylar humeral fractures in children.
METHODS:
A retrospective analysis was performed on patients diagnosed with Gravland type Ⅲ supracondylar humeral fractures between January 2022 and June 2023. A total of 46 patients were treated with closed reduction assisted by Kirschner wires and percutaneous Kirschner wire internal fixation.There were 25 males and 21 females. The age ranged from 5 to 10 years old, with an average of (5.8±1.8) years old. The left side was involved in 28 patients and the right side in 18 patients. Record the operative duration for patients, the number of fluoroscopic exposures, fracture healing time, postoperative carrying angle, Baumann angle, elbow joint function score at three months post-operation, and any associated complications.
RESULTS:
All 46 patients were followed up for a period of 12 to 16 weeks, with an average of (13.74±1.44 )weeks. The operation duration was (30.7±5.1) minutes, the fluoroscopy count was (10.2±2.7) times, the postoperative carrying angle of the elbow joint was (8.7±2.2) degrees, and the Baumann angle was (71.5±2.9) degrees. All fractures achieved successful union in all patients, with a mean healing time of (25.5±1.7) days.At the final follow-up, elbow joint function was assessed using the Flynn criteria, with 43 patients rated as excellent and 3 patients rated as good. No complications were observed, including cubitus varus, nerve injury, or local infection.
CONCLUSION
The use of a single Kirschner wire assisted prying reduction for treating Gartland type Ⅲ supracondylar humeral fractures in children demonstrates excellent clinical efficacy and safety.
Humans
;
Male
;
Female
;
Child
;
Bone Wires
;
Child, Preschool
;
Humeral Fractures/physiopathology*
;
Retrospective Studies
;
Fracture Fixation, Internal/instrumentation*
;
Treatment Outcome
;
Fracture Healing
8.Application of genome tagging technology in elucidating the function of sperm-specific protein 411 (Ssp411).
Xue-Hai ZHOU ; Min-Min HUA ; Jia-Nan TANG ; Bang-Guo WU ; Xue-Mei WANG ; Chang-Gen SHI ; Yang YANG ; Jun WU ; Bin WU ; Bao-Li ZHANG ; Yi-Si SUN ; Tian-Cheng ZHANG ; Hui-Juan SHI
Asian Journal of Andrology 2025;27(1):120-128
The genome tagging project (GTP) plays a pivotal role in addressing a critical gap in the understanding of protein functions. Within this framework, we successfully generated a human influenza hemagglutinin-tagged sperm-specific protein 411 (HA-tagged Ssp411) mouse model. This model is instrumental in probing the expression and function of Ssp411. Our research revealed that Ssp411 is expressed in the round spermatids, elongating spermatids, elongated spermatids, and epididymal spermatozoa. The comprehensive examination of the distribution of Ssp411 in these germ cells offers new perspectives on its involvement in spermiogenesis. Nevertheless, rigorous further inquiry is imperative to elucidate the precise mechanistic underpinnings of these functions. Ssp411 is not detectable in metaphase II (MII) oocytes, zygotes, or 2-cell stage embryos, highlighting its intricate role in early embryonic development. These findings not only advance our understanding of the role of Ssp411 in reproductive physiology but also significantly contribute to the overarching goals of the GTP, fostering groundbreaking advancements in the fields of spermiogenesis and reproductive biology.
Animals
;
Female
;
Humans
;
Male
;
Mice
;
Spermatids/metabolism*
;
Spermatogenesis/physiology*
;
Spermatozoa/metabolism*
;
Thioredoxins/genetics*
9.Explanation and interpretation of blood transfusion provisions for children with hematological diseases in the national health standard "Guideline for pediatric transfusion".
Ming-Yi ZHAO ; Rong HUANG ; Rong GUI ; Qing-Nan HE ; Ming-Yan HEI ; Xiao-Fan ZHU ; Jun LU ; Xiao-Jun XU ; Tian-Ming YUAN ; Rong ZHANG ; Xu WANG ; Jin-Ping LIU ; Jing WANG ; Zhi-Li SHAO ; Yong-Jian GUO ; Xin-Yin WU ; Jia-Rui CHEN ; Qi-Rong CHEN ; Jia GUO ; Ming-Hua YANG
Chinese Journal of Contemporary Pediatrics 2025;27(1):18-25
To guide clinical blood transfusion practices for pediatric patients, the National Health Commission has issued the health standard "Guideline for pediatric transfusion" (WS/T 795-2022). Blood transfusion is one of the most commonly used supportive treatments for children with hematological diseases. This guideline provides guidance and recommendations for blood transfusions in children with aplastic anemia, thalassemia, autoimmune hemolytic anemia, glucose-6-phosphate dehydrogenase deficiency, acute leukemia, myelodysplastic syndromes, immune thrombocytopenic purpura, and thrombotic thrombocytopenic purpura. This article presents the evidence and interpretation of the blood transfusion provisions for children with hematological diseases in the "Guideline for pediatric transfusion", aiming to assist in the understanding and implementing the blood transfusion section of this guideline.
Humans
;
Child
;
Hematologic Diseases/therapy*
;
Blood Transfusion/standards*
;
Practice Guidelines as Topic
10.Explanation and interpretation of the compilation of blood transfusion provisions for children undergoing hematopoietic stem cell transplantation in the national health standard "Guideline for pediatric transfusion".
Rong HUANG ; Qing-Nan HE ; Ming-Yan HEI ; Xiao-Fan ZHU ; Jun LU ; Xiao-Jun XU ; Tian-Ming YUAN ; Rong ZHANG ; Xu WANG ; Jin-Ping LIU ; Jing WANG ; Zhi-Li SHAO ; Ming-Yi ZHAO ; Yong-Jian GUO ; Xin-Yin WU ; Jia-Rui CHEN ; Qi-Rong CHEN ; Jia GUO ; Rong GUI ; Ming-Hua YANG
Chinese Journal of Contemporary Pediatrics 2025;27(2):139-143
To guide clinical blood transfusion practices for pediatric patients, the National Health Commission has issued the health standard "Guideline for pediatric transfusion" (WS/T 795-2022). Blood transfusion for children undergoing hematopoietic stem cell transplantation is highly complex and challenging. This guideline provides recommendations on transfusion thresholds and the selection of blood components for these children. This article presents the evidence and interpretation of the transfusion provisions for children undergoing hematopoietic stem cell transplantation, with the aim of enhancing the understanding and implementation of the "Guideline for pediatric transfusion".
Humans
;
Hematopoietic Stem Cell Transplantation
;
Child
;
Blood Transfusion/standards*
;
Practice Guidelines as Topic

Result Analysis
Print
Save
E-mail