The initiation of adaptive immune responses relies on the precise recognition and interpretation of antigenic information. In this process, the specific binding of T cell receptors (TCRs) to peptide-major histocompatibility complex (pMHC) molecules represents one of the key molecular events in the initiation of adaptive immune responses. Accordingly, the structural features of TCR-pMHC complexes provide a fundamental basis for dissecting antigen recognition mechanisms and support rational vaccine design, therapeutic target discovery in TCR-based immunotherapy, and TCR identification and optimization. However, experimental determination of TCR-pMHC structures remains costly, time-consuming, and limited in coverage, making computational approaches essential for rapidly obtaining reliable structural information. Computational methods for predicting the structures of TCR-pMHC complexes have advanced rapidly in recent years, driven by progress in deep learning-based modeling frameworks and the increasing availability of structural and sequence resources. Despite these developments, most existing tools do not adequately distinguish the key structural and biophysical differences between MHC class I (MHC-I) and MHC class II (MHC-II) complexes during model construction. As a consequence, their predictive performance differs substantially between class I and class II complexes. In general, structural predictions for class I complexes outperform those for class II complexes. This discrepancy may be related to several fundamental differences between the two systems, including the architecture of the peptide-binding groove, the distribution of peptide lengths, and the properties of peptide flanking residues (PFRs). Compared with MHC-I molecules, MHC-II molecules usually bind longer antigenic peptides, which typically range from 13 to 25 amino acids in length. PFRs at both termini of these peptides participate in regulating the overall conformation of TCR-pMHC class II complexes and exert a pronounced effect on the geometric and physicochemical characteristics of the TCR-pMHC binding interface. Furthermore, within the TCR recognition interface, the complementarity-determining regions (CDRs) consist of segments that differ markedly in conformational behavior. They commonly include regions that are relatively rigid and structurally stable, together with highly flexible segments exhibiting substantial conformational plasticity. These rigidity-flexibility features constitute an essential structural basis enabling TCRs to recognize diverse peptide-MHC ligands and to accommodate conformational heterogeneity at the interface. However, many current modeling tools, in an effort to enforce global conformational stability or reduce structural noise, tend to over-constrain intrinsically flexible regions. Such oversimplification may lead to inappropriate rigidification of flexible CDR loops, resulting in local structural distortions, compromised interface geometry, or even complete modeling failure for specific complexes. Against this background, the review approaches the field from the perspective of computational differences between MHC-I and MHC-II complexes. We first systematically organize and summarize available resources related to TCRs and pMHCs, including structural datasets, sequence databases, prediction tools, and benchmarking studies. We then focus on five representative tools capable of predicting both class I and class II complexes—AlphaFold2, AlphaFold3, TCRmodel2, tFold-TCR, and TCR-pHLA_ModellerS. After excluding structures present in the training sets of these tools, we constructed a benchmark dataset comprising 25 class I and 10 class II TCR-pMHC complexes in the bound state and conducted a systematic evaluation using this dataset. We first employ widely used general evaluation metrics, including All-Atom Root Mean Square Deviation (All-Atom RMSD), Backbone RMSD, Template Modeling score (TM-score), and DockQ, to assess the global conformational accuracy and interface modeling quality of class I and class II complexes. For class II complexes, we propose for the first time a peptide flanking residue deviation index, including the PFRs-Deviation Index (PFRs-DI), N-PFR-Deviation Index (N-PFR-DI), and C-PFR-Deviation Index (C-PFR-DI), to quantitatively characterize conformational deviations in PFRs. In addition, we propose the CDR conformational consistency index (CCC) designed to qualitatively evaluate the ability of prediction tools to capture TCR CDR conformational flexibility. These metrics collectively assess a tool’s ability to model both overall conformation and critical functional regions, thereby addressing the limitations of existing evaluation criteria that overemphasize global structure while inadequately capturing modeling quality in key functional areas. This establishes a unified analytical framework for MHC-I and MHC-II complexes to guide data resource selection, modeling strategy formulation, and evaluation system development. The framework further advances computational modeling and provides crucial support for multi-scale analysis of TCR-pMHC recognition mechanisms and their biological functions.

The initiation of adaptive immune responses relies on the precise recognition and interpretation of antigenic information. In this process, the specific binding of T cell receptors (TCRs) to peptide-major histocompatibility complex (pMHC) molecules represents one of the key molecular events in the initiation of adaptive immune responses. Accordingly, the structural features of TCR-pMHC complexes provide a fundamental basis for dissecting antigen recognition mechanisms and support rational vaccine design, therapeutic target discovery in TCR-based immunotherapy, and TCR identification and optimization. However, experimental determination of TCR-pMHC structures remains costly, time-consuming, and limited in coverage, making computational approaches essential for rapidly obtaining reliable structural information. Computational methods for predicting the structures of TCR-pMHC complexes have advanced rapidly in recent years, driven by progress in deep learning-based modeling frameworks and the increasing availability of structural and sequence resources. Despite these developments, most existing tools do not adequately distinguish the key structural and biophysical differences between MHC class I (MHC-I) and MHC class II (MHC-II) complexes during model construction. As a consequence, their predictive performance differs substantially between class I and class II complexes. In general, structural predictions for class I complexes outperform those for class II complexes. This discrepancy may be related to several fundamental differences between the two systems, including the architecture of the peptide-binding groove, the distribution of peptide lengths, and the properties of peptide flanking residues (PFRs). Compared with MHC-I molecules, MHC-II molecules usually bind longer antigenic peptides, which typically range from 13 to 25 amino acids in length. PFRs at both termini of these peptides participate in regulating the overall conformation of TCR-pMHC class II complexes and exert a pronounced effect on the geometric and physicochemical characteristics of the TCR-pMHC binding interface. Furthermore, within the TCR recognition interface, the complementarity-determining regions (CDRs) consist of segments that differ markedly in conformational behavior. They commonly include regions that are relatively rigid and structurally stable, together with highly flexible segments exhibiting substantial conformational plasticity. These rigidity-flexibility features constitute an essential structural basis enabling TCRs to recognize diverse peptide-MHC ligands and to accommodate conformational heterogeneity at the interface. However, many current modeling tools, in an effort to enforce global conformational stability or reduce structural noise, tend to over-constrain intrinsically flexible regions. Such oversimplification may lead to inappropriate rigidification of flexible CDR loops, resulting in local structural distortions, compromised interface geometry, or even complete modeling failure for specific complexes. Against this background, the review approaches the field from the perspective of computational differences between MHC-I and MHC-II complexes. We first systematically organize and summarize available resources related to TCRs and pMHCs, including structural datasets, sequence databases, prediction tools, and benchmarking studies. We then focus on five representative tools capable of predicting both class I and class II complexes—AlphaFold2, AlphaFold3, TCRmodel2, tFold-TCR, and TCR-pHLA_ModellerS. After excluding structures present in the training sets of these tools, we constructed a benchmark dataset comprising 25 class I and 10 class II TCR-pMHC complexes in the bound state and conducted a systematic evaluation using this dataset. We first employ widely used general evaluation metrics, including All-Atom Root Mean Square Deviation (All-Atom RMSD), Backbone RMSD, Template Modeling score (TM-score), and DockQ, to assess the global conformational accuracy and interface modeling quality of class I and class II complexes. For class II complexes, we propose for the first time a peptide flanking residue deviation index, including the PFRs-Deviation Index (PFRs-DI), N-PFR-Deviation Index (N-PFR-DI), and C-PFR-Deviation Index (C-PFR-DI), to quantitatively characterize conformational deviations in PFRs. In addition, we propose the CDR conformational consistency index (CCC) designed to qualitatively evaluate the ability of prediction tools to capture TCR CDR conformational flexibility. These metrics collectively assess a tool’s ability to model both overall conformation and critical functional regions, thereby addressing the limitations of existing evaluation criteria that overemphasize global structure while inadequately capturing modeling quality in key functional areas. This establishes a unified analytical framework for MHC-I and MHC-II complexes to guide data resource selection, modeling strategy formulation, and evaluation system development. The framework further advances computational modeling and provides crucial support for multi-scale analysis of TCR-pMHC recognition mechanisms and their biological functions.

Background/Aims: Liver transplantation (LT) following total hepatectomy is a life-saving treatment for hepatocellular carcinoma (HCC). The HCC recurrence after LT hinders the effectiveness of the procedure. The objective of this study is to develop a pre-operative risk stratification model based on a liquid biopsy. Methods: We conducted a comprehensive multi-omics study of 260 HCC patients from three centers, including clinical data, low-coverage whole-genome sequencing of cell-free DNA (cfDNA) from plasma, as well as whole-exome, single-nucleus RNA, and spatial transcriptomics from matched tumor and non-tumor tissues. Results: We identified cfDNA-derived copy number alteration (CNA) signatures associated with post-transplant recurrence. By integrating cfDNA-derived CNA profiles with single-cell transcriptomic data, we traced recurrence-associated cfDNA to a distinct subpopulation of malignant cells within the primary tumor. These cells were embedded in a pro-metastatic microenvironment of specialized endothelial subtypes and cancer-associated fibroblasts. Notably, most recurrence-associated lesions were detectable in cfDNA prior to liver transplantation (LT). Building on these insights, we developed the ZJU Criteria based on CNA fragments and tumor markers, a pre-LT risk prediction tool that integrates conventional clinical factors with cfDNA-derived CNA signatures, and validated it using internal and independent external cohorts. Conclusion Our findings suggest that post-transplant recurrence commonly originates from advanced subclones that emerge late during tumor evolution. The ZJU Criteria provides an accurate, non-invasive strategy that significantly improves pre-LT risk stratification and clinical decision-making for patients with HCC.

Echinococcosis is categorized into alveolar echinococcosis and cystic echinococcosis, a potentially fatal zoonotic disease that seriously damages the host. MicroRNA is a type of endogenous small non-coding RNA that binds specifically to the target gene mRNA sequence to promote mRNA degradation, or combines with other non-coding RNA to regulate or inhibit translation. Echinococcus-derived microRNA participates in various biological processes in the Echinococcus lifecycle and in the interaction and pathogenesis between Echinococcus and host through extracellular vesicle transport. This article reviews the research progress of parasite-derived microRNA in regulating the growth and development of echinococcosis and cross-species regulation of hosts, providing a reference for diagnosing and treating echinococcosis.

ObjectiveTo observe the effect and therapeutic effect of Kaixuan Jiedu core prescription （KXJD） on skin homing of Th17 cells in the mouse model of imiquimod （IMQ） combined with restraint stress-induced psoriasis-like skin damage， and to explore its potential mechanism from the perspective of neuro-immune axis. MethodsThirty male C57BL/6J mice were randomly allocated into five groups （n=6）： Control， model （IMQ）， restraint stress model （IMQ+RS）， KXJD， and methotrexate （MTX）. The mouse model of psoriasis-like skin damage was established by 5% IMQ combined with restraint stress. At the same time of modeling， each treatment group was treated with corresponding doses of drugs， and the control， IMQ， and IMQ+RS groups were treated with the same amount of normal saline by gavage once a day for 5 days. Hematoxylin-eosin （HE） staining was used to observe the pathological changes in the skin tissue and Baker scoring was performed. Serum levels of interleukin-1β （IL-1β） and angiopoietin-2 （Ang-2） were measured by enzyme-linked immunosorbent assay （ELISA）. The levels of matrix metalloproteinase-9 （MMP-9）， tissue inhibitor of metalloproteinase-1 （TIMP-1）， C-C motif chemokine ligand 20 （CCL20）， and C-C motif chemokine receptor 6 （CCR6） in the skin tissue were determined. Immunohistochemistry （IHC） was employed to determine the protein expression of cutaneous lymphocyte-associated antigen （CLA）， integrin α_E （CD103）， cytokeratin 10 （CK10）， and nuclear factor-kappa B （NF-κB） in the skin. Immunofluorescence double staining （DIF） was adopted to detect the expression and co-localization of vascular endothelial cadherin （VE-cadherin） and platelet-endothelial cell adhesion molecule （CD31）， CCR6， CD103， substance P （SP）， calcitonin gene-related peptide （CGRP）， and protein gene product 9.5 （PGP9.5） in the skin tissue. Real-time PCR was employed to quantify the mRNA levels of IL-10， IL-17A， and IL-23. ResultsCompared with the control group， the IMQ group and IMQ+RS group showed significant inflammatory cell infiltration， abnormal proliferation of epidermal cells， keratinization and other pathological changes in the skin tissue， and a significant increase in Baker score， elevated levels of IL-1β and Ang-2 in the serum and MMP-9， CCL20 and CCR6 in the skin lesions， upregulated expression of CLA， CD103， CK10， NF-κB， IL-17A mRNA， and IL-23 mRNA in the skin lesions， and downregulated expression of TIMP-1 and IL-10 mRNA. In addition， the fluorescence intensities of VE-cadherin and CD31 co-localization， CCR6 and CD103 co-localization， SP and PGP9.5 co-localization， and CGRP and PGP9.5 co-localization were increased （P<0.05）. Compared with the IMQ group， the above indicators in the IMQ+RS group were further aggravated. Compared with the IMQ group， the above indicators in the IMQ+RS group were further aggravated. Compared with the IMQ+RS group， KXJD and MTX significantly alleviated the pathological damage of skin lesions， significantly decreased the Baker score， lowered the levels of IL-1β and Ang-2 in the serum and MMP-9， CCL20 and CCR6 in skin lesions， downregulated the expression of CLA， CD103， CK10， NF-κB， IL-17A mRNA and IL-23 mRNA in skin lesions， and upregulated the expression of TIMP-1 and IL-10 mRNA. Furthermore， KXJD and MTX reduced the fluorescence intensities of VE-cadherin and CD31 co-localization， CCR6 and CD103 co-localization， CGRP and PGP9.5 co-localization， and SP and PGP9.5 co-localization （P<0.05）. ConclusionKXJD can significantly ameliorate the psoriasis-like skin damage induced by IMQ combined with restraint stress in mice by regulating the neural-immune axis and inhibiting the skin homing of Th17 cells.

ObjectiveTo establish the mouse models of psoriasis-like lesions induced by continuous cold exposure or intermittent cold exposure combined with imiquimod （IMQ）， and to evaluate the interventional effects of Kaixuan Jiedu core prescription （KXJD） on the two models. MethodsMale C57BL/6J mice were selected and classified into two experimental batches. The first batch of 36 mice was randomized into a room temperature group， a continuous cold exposure （10 ℃/24 h） group， and an intermittent cold exposure （10 ℃/6 h） group. Each group was further divided into a normal subgroup and a model subgroup （topical application of IMQ to induce skin lesions）， with 6 mice in each subgroup， for modeling and evaluation. The second batch of 54 mice， with 6 in each group， were subjected to the same temperature grouping with an additional KXJD （30.42 g·kg^-1， continuous gavage for 5 days） group. Comprehensive evaluation of model characteristics and KXJD efficacy was conducted through Psoriasis Area and Severity Index （PASI） scoring， skin temperature measurement by infrared thermography， histopathological observation by hematoxylin-eosin （HE） staining， detection of vascular endothelial growth factor （VEGF） and platelet endothelial cell adhesion molecule 1 （CD31） by immunohistochemistry， detection of Claudin-1 and Occludin by immunofluorescence assay， determination of serum levels of tumor necrosis factor-α （TNF-α） and interleukin （IL）-10 by enzyme-linked immunosorbent assay （ELISA）， and quantification of mRNA levels of IL-17A， IL-23， IL-6， and chemokine ligand 20 （CCL20） in skin lesions by quantitative Real-time polymerase chain reaction （Real-time PCR）. ResultsModel mice in all temperature groups exhibited typical psoriasis-like skin lesions. Compared with the normal groups， the model groups showed increased PASI scores， decreased skin temperatures （P<0.05）， obvious epidermal thickening， parakeratosis， and dermal inflammatory cell infiltration， as well as elevated mRNA levels of IL-17A， IL-23， IL-6， and CCL20 （P<0.05）. Cold exposure further aggravated psoriasis. The total PASI score of the intermittent cold exposure model group was higher than that of the room temperature model group （P<0.05）. The serum IL-10 did not show a compensatory elevation， and the blood vessels presented a characteristic of elevated CD31 expression （P<0.05） without a synchronous increase in VEGF. The continuous cold exposure model group exhibited more significant dermal capillary tortuosity and dilation， with the highest mRNA levels of IL-17A， IL-23， IL-6， and CCL20 among all groups. Compared with the respective model groups， KXJD intervention alleviated skin lesions， reduced epidermal thickness and inflammatory cell infiltration， and increased skin temperature， with the temperature increase being particularly significant in the intermittent cold exposure+KXJD group （P<0.05）. Furthermore， KXJD down-regulated the expression of VEGF and CD31， restored the expression of Claudin-1 and Occludin， decreased the mRNA levels of IL-17A and IL-23 （P<0.05）， and reduced the serum TNF-α level. ConclusionThis study successfully established compound psoriasis-like mouse models induced by cold exposure combined with IMQ. It confirms that cold aggravates the severity of psoriasis by exacerbating the closure of Xuanfu （sweat pores）， microcirculation disorders， and immune imbalance. Moreover， different cold exposure patterns have distinct mechanism differences. Continuous cold exposure focuses on enhancing the inflammatory response via the IL-23/IL-17 axis and angiogenesis， simulating chronic aggravation under a long-term cold environment. Intermittent cold exposure tends to impair immune regulation and induce microvascular endothelial stress， corresponding to acute exacerbations caused by sudden temperature drops. KXJD can effectively alleviate psoriasis-like skin lesions under cold conditions by unblocking Xuanfu， regulating vasomotor function， and correcting abnormal immune-inflammatory responses.

ObjectiveTo investigate the ameliorative effects of Kaixuan Jiedu core prescription （KXJD） on skin lesions in psoriasis-like mouse models under cold environment exposure， and to analyze its influences on transient receptor potential （TRP） channels and related neuroimmune regulatory factors. MethodsThirty-six C57BL/6J mice were randomized into 6 groups， with 6 mice in each group. Two feeding conditions were set： Normal temperature and cold ［simulating a cold environment at （10±0.5） ℃， for 6 h daily］. Mice were induced to develop psoriasis-like lesions by applying imiquimod externally. The model mice were allocated into model groups and KXJD （30.42 g·kg^-1， continuous gavage for 5 days） groups. Normal mice were used as the control group. Specifically， mice were allocated into normal temperature， normal temperature model， normal temperature+KXJD， cold exposure control， cold exposure model， and cold exposure+KXJD groups. The pathological changes in skin lesions were observed by hematoxylin-eosin （HE） staining. The expression of cluster of differentiation （CD） 3⁺ T lymphocytes， CD11c⁺ dendritic cells （DCs）， phosphorylated extracellular signal-regulated kinase （p-ERK）， and substance P （SP） were detected by immunofluorescence assay. The protein level of transient receptor potential cation channel subfamily M member 8 （TRPM8） in the skin tissue was determined by Western blot. The expression of TRPM8， transient receptor potential cation channel subfamily V member 1 （TRPV1）， transient receptor potential cation channel subfamily A member 1 （TRPA1）， and transient receptor potential cation channel subfamily V member 2 （TRPV2） at the protein and mRNA levels was determined by immunohistochemistry and Real-time PCR， respectively. The levels of calcitonin gene-related peptide （CGRP） and neuropeptide Y （NPY） in the serum were analyzed by enzyme-linked immunosorbent assay （ELISA）. The enrichment analysis of differentially expressed genes （DEGs） and TRP pathway network construction were conducted based on the GEO database. The co-expression of TRPM8 and CGRP in the skin lesions was verified by immunofluorescence double labeling. ResultsBoth the normal temperature and cold exposure model groups showed typical psoriasis-like skin lesions. Compared with the normal temperature and cold exposure control groups， the model groups had excessive epidermal keratinization， thickened spinous layer， and inflammatory infiltration in the dermis， with increased pathological scores （P<0.05）， increased infiltration of CD3⁺ and CD11c⁺ cells and expression of p-ERK and SP， upregulated mRNA levels of TRPM8， TRPA1， and TRPV2， downregulated mRNA level of TRPV1 （P<0.05）， and reduced content of CGRP and increased content of NPY in the serum. Compared with the normal temperature and cold exposure model groups， KXJD reduced the pathological manifestations and pathological scores of psoriasis-like skin lesions （P<0.05）， and inhibited the infiltration of CD3⁺ and CD11c⁺ cells and the expression of p-ERK and SP. Gene enrichment analysis suggested that the DEGs of psoriasis were significantly enriched in the interleukin （IL）-17 signaling pathway and TRP channel inflammatory regulation. Compared with the normal temperature and cold exposure model groups， KXJD reversed the abnormal mRNA levels of genes related to the TRP channel subfamilies （P<0.05）， increased the CGRP level， and decreased the NPY level. Immunofluorescence double labeling further confirmed that compared with the model groups， KXJD down-regulated the co-expression of TRPM8 and CGRP in the skin lesions. ConclusionKXJD may ameliorate psoriasis-like skin lesions by downregulating the overexpressed cold-sensitive receptor TRPM8 in skin lesions and correcting the disorder of neuropeptide （such as SP and CGRP） release mediated by it， thereby inhibiting the IL-23/helper T cell 17 （Th17） core inflammatory pathway， suppressing the infiltration of inflammatory cells and the activation of the ERK signaling pathway， and regulating the Xuanfu （sweat pore）-TRPM8-neuroimmune response axis.

ObjectiveTo investigate the ameliorative effects and mechanisms of Kaixuan Jiedu core prescription （KXJD） on neuroimmunological inflammation in imiquimod （IMQ）-induced psoriasis-like mice. MethodsA total of 24 C57BL/6J mice were randomly divided into four groups （n=6）： Normal， model， KXJD， and tropomyosin receptor kinase A （TrkA） inhibitor GW441756 groups. The mice in the model， KXJD， and GW441756 groups were topically treated with 5% IMQ cream （62.5 mg·d^-1） on the back to induce psoriasis-like inflammation. The KXJD group received KXJD by gavage （30.42 g·kg^-1）， the GW441756 group received intraperitoneal injection of GW441756 （10 mg·kg^-1）， and the normal and model groups received an equal volume of normal saline by gavage， with continuous intervention for 5 days. The severity of skin lesions was evaluated using the psoriasis area and severity index （PASI）. Hematoxylin-eosin （HE） staining was used to measure epidermal thickness and observe pathological changes in the lesioned skin. Immunohistochemistry was employed to detect the expression of proliferating cell nuclear antigen （Ki67） and interleukin-17A （IL-17A） in the lesioned skin. Enzyme-linked immunosorbent assay （ELISA） was used to quantify the levels of interleukin-23 （IL-23） and calcitonin gene-related peptide （CGRP） in the lesioned tissues. Western blot was used to detect the expression of TrkA and phosphorylated TrkA （p-TrkA）. Immunofluorescence assay was performed to detect the expression of TrkA receptor， protein gene product 9.5 （PGP9.5）， cluster of differentiation 11c （CD11c）， and CGRP in the lesions. Flow cytometry was used to detect the activation of splenic dendritic cells （DCs）. ResultsCompared with the normal group， the model group exhibited typical psoriasis-like inflammation， characterized by erythema， infiltration and scaling， with histopathological findings of epidermal hyperkeratosis and acanthosis. The model group showed significantly increased expression of Ki67， IL-17A， IL-23 and p-TrkA （P<0.05， P<0.01）， increased fluorescence intensity of CD11c， and significantly decreased CGRP expression （P<0.05）. The splenic DC activation was significantly enhanced， as indicated by the increased mean fluorescence intensity （MFI） of CD86 （P<0.05）. Compared with the model group， both the KXJD and GW441756 groups showed amelioration of the psoriasis-like skin inflammation， with significantly down-regulated expression of IL-17A， IL-23 and p-TrkA （P<0.05， P<0.01）， significantly up-regulated expression of CGRP （P<0.01）， reduced CD11c⁺ DC infiltration， and restored splenic DC activation balance （down-regulated CD86 MFI and up-regulated CD80 and CD40 MFI）. Furthermore， the inhibitory effect of KXJD on Ki67 was significantly superior to that of the GW441756 group （P<0.01）. ConclusionKXJD may alleviate IMQ-induced psoriasis-like inflammation in mice by targeting and inhibiting TrkA receptor phosphorylation， regulating CGRP expression in the lesions， and ameliorating aberrant activation of dendritic cells， while also significantly inhibiting keratinocyte proliferation.

ObjectiveTo investigate the effects and molecular mechanisms of Kaixuan Jiedu core prescription （KXJD） on neuroinflammation and immuno-inflammation in the mouse model of imiquimod （IMQ）-induced psoriasis-like skin lesions by regulating the nerve growth factor （NGF）-tropomyosin receptor kinase A （TrkA）/transient receptor potential vanilloid 1 （TRPV1）-protease-activated receptor-2 （PAR-2） signaling pathway. MethodsA psoriasis-like skin lesion model was established in male C57BL/6J mice with IMQ. A total of 24 mice were randomized into four groups （n=6 per group）： Blank control， model， methotrexate （MTX， 1 mg·kg^-1）， and KXJD （30.42 g·kg^-1）. Immunohistochemistry was employed to detect the expression of cluster of differentiation 3 （CD3）， EGF-like module-containing mucin-like hormone receptor-like 1 （F4/80）， lymphocyte antigen 6 complex locus G （Ly-6G）， substance P （SP）， calcitonin gene-related peptide （CGRP）， NGF， phosphorylated TrkA （p-TrkA）， phosphorylated TRPV1 （p-TRPV1）， and PAR-2 in skin lesions. Serum levels of interleukin-17A （IL-17A） and interleukin-23 （IL-23） were measured by enzyme-linked immunosorbent assay （ELISA）. Immunofluorescence assay and Western blot were employed to determine the expression of phosphorylated p38 mitogen-activated protein kinase （p-p38 MAPK） and phosphorylated nuclear factor-κB p65 （p-NF-κB p65）. Reverse transcription quantitative polymerase chain reaction （Real-time PCR） was used to measure the mRNA levels of interleukin-1β （IL-1β）， tumor necrosis factor （TNF）， interleukin-6 （IL-6）， and C-X-C motif chemokine ligand 1 （CXCL1） in skin lesions. Correlation analysis was performed. ResultsCompared with the blank control group， the model group showed increased positive areas of CD3⁺， F4/80⁺， and Ly-6G⁺ in skin lesions （P<0.05）， elevated serum levels of IL-17A and IL-23 （P<0.05）， increased positive areas of SP and CGRP in skin lesions （P<0.05）， increased positive areas of NGF， p-TrkA， p-TRPV1， and PAR-2 （P<0.05）， elevated ratios of p-p38 MAPK/p38 MAPK and p-NF-κB p65/NF-κB p65 （P<0.05）， and upregulated mRNA levels of IL-1β， TNF， IL-6， and CXCL1 （P<0.05）. Compared with those in the model group， all the above indicators were reversed in the KXJD group （P<0.05）. MTX only downregulated the expression of p-TRPV1 and PAR-2 （P<0.05）， with no significant effects on the expression of NGF， p-TrkA， or CGRP. ConclusionKXJD inhibits the NGF-TrkA/TRPV1-PAR-2 signaling pathway to reduce neuropeptide release and simultaneously downregulates the p38 MAPK/NF-κB signaling pathway and the expression of downstream pro-inflammatory factors to ameliorate psoriasis-like neuroinflammation and immuno-inflammation. The therapeutic effect of KXJD on psoriasis-like inflammation is closely associated with the inhibition of the NGF-TrkA/TRPV1-PAR-2 signaling pathway. This study provides experimental evidence for the modern interpretation of the Xuanfu theory.

ObjectiveTo identify the active constituents of Kaixuan Jiedu core prescription （KXJD） and investigate its effective components and therapeutic targets in the treatment of common psoriasis. MethodsUltra-performance liquid chromatography-high resolution mass spectrometry （UPLC-Q-TOF MS） was used to identify and analyze the chemical components of KXJD and its blood-entering chemical components. The chemical components of the single decoction were further identified to clarify the source of the chemical components in KXJD. Then， all identified blood-entering compounds were screened for effective active ingredients through the Swiss ADME database. The active ingredient targets of KXJD were searched on the Swiss Target Prediction platform. The targets of common psoriasis were searched in OMIM， GEO， GeneCards， and DISGNET databases to obtain drug-disease intersection targets. The protein-protein interaction network of intersection targets was constructed using STRING， and then the core blood-entering component-intersection target network of KXJD was constructed. The core target proteins in the network were selected for molecular docking with the core components of KXJD. Small molecules and proteins were pretreated， and appropriate docking sites were selected. AutoDock Vina software was used for continuous local search and repeated iterations to find molecular docking conformations. PyMOL software and LigPlot+ software were used for analysis and visualization. Subsequently， the verification was carried out through animal experiments. SPF-grade male C57 mice were randomly divided into a blank group， a model group， a positive drug methotrexate group， and a KXJD group. In the model group， the methotrexate group， and the KXJD group， imiquimod was applied to the backs of the mice for modeling. The blank group and the model group were administered normal saline by gavage， while the methotrexate group and the KXJD group were respectively administered 1 mg·kg^-1 suspension and 30.42 g·kg^-1 decoction of traditional Chinese medicine by gavage. Five days after administration， the mice were sacrificed， and samples were collected. Hematoxylin-eosin （HE） staining was used to observe the skin tissue samples of mice， and the effect of KXJD on the pathological manifestations of psoriasis mice was analyzed. The expression areas of tumor necrosis factor-α （TNF-α）， cyclooxygenase 2 （PTGS2）， interleukin （IL）-1β， and IL-6 in the skin tissue of mice were detected by immunohistochemistry （IHC）. The mRNA expressions of TNF-α， IL-1β， IL-6， and PTGS2 in the skin tissue of mice were detected by real-time fluorescent quantitative polymerase chain reaction （Real-time PCR）. ResultsIn this study， 208 compounds in KXJD were identified by UPLC-Q-TOF MS， and 44 compounds were detected in serum， including 28 prototype components and 16 metabolites. 12 blood-entering active components were screened， and 1 153 active component targets and 1 076 psoriasis-related targets were identified. Eighty-five targets in the intersection set were drug-disease common targets. PPI network analysis showed that TNF-α， IL-1β， IL-6， PTGS2， and ALB were the key target proteins. The results of molecular docking showed that the binding ability of （+）-hexylphenylglycolic acid to key target proteins such as PTGS2 was stable， and PTGS2 showed high stability with a variety of core compounds. Compared with those in the blank group， the stratum corneum and epidermis in the model group mice were significantly thickened， and the pathological Baker score of the mice's skin in the model group was significantly higher than that of the blank group （P<0.01）. The expression areas of PTGS2， TNF-α， IL-1β， and IL-6 proteins in the skin tissue of the model group mice were significantly increased （P<0.01）， and the expression levels of PTGS2， TNF-α， IL-1β， and IL-6 mRNA in the skin tissue of the model group mice were significantly elevated （P<0.01）. Compared with the model group， the pathological Baker scores of the methotrexate group and the KXJD group were both decreased （P<0.01）， and the expression areas in the skin tissue of the methotrexate group and the KXJD group were significantly reduced （P<0.05， P<0.01）. The expression levels of PTGS2， TNF-α， IL-1β， and IL-6 mRNA in the skin tissue of the methotrexate group and the KXJD group were significantly decreased （P<0.01）. ConclusionKXJD can effectively improve the skin lesions of psoriasis model mice and reduce the expression of TNF-α， IL-1β， IL-6， and PTGS2 in the skin tissue of psoriasis model mice. PTGS2 has a stable binding ability with a variety of compounds in the decoction， which may be a key target for the treatment of psoriasis. The compound （+）-hexylphenylglycolic acid may play a key role.