Characteristics analysis of hepatitis B core-related antigen in children with hepatitis B e antigen-positive chronic viral hepatitis B infection.

BACKGROUND: The objective of antiviral therapy for chronic viral hepatitis B infection (CHB) is to achieve a functional cure. An important viral marker in the serum of patients with CHB is the serum hepatitis B core-related antigen (HBcrAg). However, there is limited research on HBcrAg in juvenile patients with CHB. In this study, we aimed to investigate the correlation between serum HBcrAg and other hepatitis B virus (HBV) markers in children with CHB and its predictive significance for prognosis during antiviral therapy. METHODS: A single-center retrospective study was conducted involving 79 children with CHB, aged between 0 and 16 years. All the children were treated with interferon [or combined nucleos(t)ide analogs] for 48 weeks. HBcrAg, hepatitis B surface antigen (HBsAg), and HBV DNA were measured before treatment, and at 12 and 48 weeks after treatment. The enrolled children were classified into the seroclearance group and the nonseroclearance group based on the therapeutic outcome. RESULTS: HBsAg seroclearance was observed in 28 out of 79 patients and hepatitis B e antigen seroconversion without HBsAg seroclearance was observed in 14 out of 79 patients following the conclusion of the treatment, with baseline HBcrAg titer levels showing no statistical significance in both the seroclearance and nonseroclearance groups (P = 0.277). HBsAg and HBV DNA were positively correlated with HBcrAg in children with CHB (R2 = 0.3289, 0.4388). The area under the receiver operating characteristic curve of the decrease in HBcrAg at 12 weeks of treatment as a predictor of seroclearance at 48 weeks of treatment, exhibited a value of 0.77. CONCLUSION: A decrease in serum HBcrAg levels in children with hepatitis B serves as a prognostic indicator.

A Novel Quality Control Strategy for the Preparation of High-Quality Recombinant Allergens in Escherichia coli: A Case Study of Der f 2.

INTRODUCTION: Recombinant allergens produced by Escherichia coli (E. coli) system play an important role in the component-resolved diagnostics of allergy and vaccine development. However, incorrect folding of recombinant allergens may affect their application. Therefore, it is very important to monitor the correct folding of recombinant allergens. Currently, there is still a lack of a quality control strategy to solve this problem. In this study, a mite allergen, Der f 2, was taken as an example to establish a novel quality control strategy, which was based on chromatography to isolate the allergen, and on enzyme-linked immunosorbent assay to verify the IgE reactivity of the isolated allergen. METHODS: The nucleotide sequence encoding Der f 2 was codon-optimized and cloned into pET-28a (+) plasmid. Best conditions for the expression of Der f 2 in E. coli were sought. The inclusion body of Der f 2 was denatured and purified by nickel affinity chromatography. Refolding processes were compared using glutathione redox system. The fully and partially folded proteins were separated by anion exchange chromatography, and the IgE reactivity of the isolated proteins was verified by indirect enzyme-linked immunosorbent assay. RESULTS: An optimized 387 bp segment of the Der f 2 coding gene was successfully expressed in E. coli. Best induction conditions included preinduction bacterial density with absorbance value at 600 nm was 0.6, 1 mM isopropyl beta-d-thiogalactopyranoside at 28°C for 4 h. The Der f 2 protein after refolding was separated by chromatography and two fractions were obtained. The first fraction was identified as monomer protein and the second as aggregate by size-exclusion chromatography. Indirect enzyme-linked immunosorbent assay also confirmed that the first fraction showed higher IgE reactivity. CONCLUSION: In this study, a novel quality control strategy based on chromatographic separation and IgE reactivity monitoring was established in the case of mite Der f 2, which systematically evaluated the effectiveness of multiple preparation methods for the first time. It is faster and more convenient when compared with the existing methods such as size-exclusion chromatography. This strategy laid a foundation for the stable application of recombinant allergens produced by E. coli in component-resolved diagnostics and the development of molecular vaccines in the future.

Activation of PPAR-α attenuates myocardial ischemia/reperfusion injury by inhibiting ferroptosis and mitochondrial injury via upregulating 14-3-3η.

This study aimed to explore the effects of peroxisome proliferator-activated receptor α (PPAR-α), a known inhibitor of ferroptosis, in Myocardial ischemia/reperfusion injury (MIRI) and its related mechanisms. In vivo and in vitro MIRI models were established. Our results showed that activation of PPAR-α decreased the size of the myocardial infarct, maintained cardiac function, and decreased the serum contents of creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), and Fe2+ in ischemia/reperfusion (I/R)-treated mice. Additionally, the results of H&E staining, DHE staining, TUNEL staining, and transmission electron microscopy demonstrated that activation of PPAR-α inhibited MIRI-induced heart tissue and mitochondrial damage. It was also found that activation of PPAR-α attenuated MIRI-induced ferroptosis as shown by a reduction in malondialdehyde, total iron, and reactive oxygen species (ROS). In vitro experiments showed that intracellular contents of malondialdehyde, total iron, LDH, reactive oxygen species (ROS), lipid ROS, oxidized glutathione disulphide (GSSG), and Fe2+ were reduced by the activation of PPAR-α in H9c2 cells treated with anoxia/reoxygenation (A/R), while the cell viability and GSH were increased after PPAR-α activation. Additionally, changes in protein levels of the ferroptosis marker further confirmed the beneficial effects of PPAR-α activation on MIRI-induced ferroptosis. Moreover, the results of immunofluorescence and dual-luciferase reporter assay revealed that PPAR-α achieved its activity via binding to the 14-3-3η promoter, promoting its expression level. Moreover, the cardioprotective effects of PPAR-α could be canceled by pAd/14-3-3η-shRNA or Compound C11 (14-3-3η inhibitor). In conclusion, our results indicated that ferroptosis plays a key role in aggravating MIRI, and PPAR-α/14-3-3η pathway-mediated ferroptosis and mitochondrial injury might be an effective therapeutic target against MIRI.

Identification and Characterization of Pectate Lyase as a Novel Allergen in Artemisia sieversiana Pollen.

INTRODUCTION: Artemisia species are widely spread in north hemisphere. Artemisia sieversiana pollen is one of the common pollen allergens in the north of China. At present, seven allergens were identified and had been listed officially from A. sieversiana pollen, but the remaining allergens are still insufficiently studied, which need to be found. METHODS: Pectate lyase was purified from the extracts of A. sieversiana pollen by anion exchange, size exclusion, and HPLC-hydrophobic interaction chromatography. The gene of A. sieversiana pectate lyase (Art si pectate lyase) was cloned and expressed in Escherichia coli. The enzyme activity and circular dichroism (CD) spectrum of natural and recombinant proteins were analyzed. The allergenicity of Art si pectate lyase was characterized by enzyme-linked immunosorbent assay (ELISA), Western blot, inhibition ELISA, and basophil activation test. The allergen's physicochemical properties, three-dimensional structure, sequence profiles with homologous allergens and phylogenetic tree were analyzed by in silico methods. RESULTS: Natural Art si pectate lyase (nArt si pectate lyase) was purified from A. sieversiana pollen extracts by three chromatographic strategies. The cDNA sequence of Art si pectate lyase had a 1191-bp open reading frame encoding 396 amino acids. Both natural and recombinant pectate lyase (rArt si pectate lyase) exhibited similar CD spectrum, and nArt si pectate lyase had higher enzymatic activity. Moreover, the specific immunoglobulin E (IgE) binding rate against nArt si pectate lyase and rArt si pectate lyase was determined as 40% (6/15) in patients' serum with Artemisia species pollen allergy by ELISA. The nArt si pectate lyase and rArt si pectate lyase could inhibit 76.11% and 47.26% of IgE binding activities to the pollen extracts, respectively. Art si pectate lyase was also confirmed to activate patients' basophils. Its structure contains a predominant motif of classic parallel helical core, consisting of three parallel ß-sheets, and two highly conserved features (vWiDH, RxPxxR) which may contribute to pectate lyase activity. Moreover, Art si pectate lyase shared the highest sequence identity of 73.0% with Art v 6 among currently recognized pectate lyase allergen, both were clustered into the same branch in the phylogenetic tree. CONCLUSION: In this study, pectate lyase was identified and comprehensively characterized as a novel allergen in A. sieversiana pollen. The findings enriched the allergen information for this pollen and promoted the development of component-resolved diagnosis and molecular therapy of A. sieversiana pollen allergy.

Advancing treatment strategies for posterior malleolar malunion: The ankle dislocation method.

BACKGROUND: This study aimed to assess the radiological and clinical outcomes of treatment using the ankle dislocation method for posterior malleolar malunion. METHOD: Thirty-one patients with posterior malleolar malunion who underwent treatment using the ankle dislocation method from May 2015 to October 2021 were retrospectively analyzed. Key outcome measures were radiographic parameters (articular step-off, tibiofibular clear space, fibular length, tibial lateral surface angle, and ankle osteoarthritis), clinical scores (American Orthopaedic Foot and Ankle Society ankle-hindfoot scale and Visual Analogue Scale), and patient satisfaction rate. RESULT: Preoperative computed tomography revealed that Bartoní cek types 3 and 4 accounted for 64.5 % (n = 20) of total cases. Most posterior malleolar malunions were accompanied by depressed intercalary fragments (61.2 % [n = 19]). At the final follow-up, radiographic parameters and clinical scores showed significant improvements postoperatively (P < 0.05), with a high patient satisfaction rate of 77.4 %. Subgroup analysis revealed that the posterior malleolar fracture morphology significantly affected postoperative pain, particularly in more complex fractures (P < 0.001). CONCLUSION: The ankle dislocation method effectively exposes the distal tibial articular surface and facilitates the anatomical restoration of joint congruity under direct vision. This approach substantially improves the clinical and imaging outcomes in patients with complex posterior malleolar malunion. LEVELS OF EVIDENCE: Level IV, retrospective case series.

Exploring the molecular biology of ischemic cardiomyopathy based on ferroptosis­related genes.

Ischemic cardiomyopathy (ICM) is a serious cardiac disease with a very high mortality rate worldwide, which causes myocardial ischemia and hypoxia as the main damage. Further understanding of the underlying pathological processes of cardiomyocyte injury is key to the development of cardioprotective strategies. Ferroptosis is an iron-dependent form of regulated cell death characterized by the accumulation of lipid hydroperoxides to lethal levels, resulting in oxidative damage to the cell membrane. The current understanding of the role and regulation of ferroptosis in ICM is still limited, especially in the absence of evidence from large-scale transcriptomic data. Through comprehensive bioinformatics analysis of human ICM transcriptome data obtained from the Gene Expression Omnibus database, the present study identified differentially expressed ferroptosis-related genes (DEFRGs) in ICM. Subsequently, their potential biological mechanisms and cross-talk were analyzed, and hub genes were identified by constructing protein-protein interaction networks. Ferroptosis features such as reactive oxygen species generation, changes in ferroptosis marker proteins, iron ion aggregation and lipid oxidation, were identified in the H9c2 anoxic reoxygenation injury model. Finally, the diagnostic ability of Gap junction alpha-1 (GJA1), Solute carrier family 40 member 1 (SLC40A1), Alpha-synuclein (SNCA) were identified through receiver operating characteristic curves and the expression of DEFRGs was verified in an in vitro model. Furthermore, potential drugs (retinoic acid) that could regulate ICM ferroptosis were predicted based on key DEFRGs. The present article presents new insights into the role of ferroptosis in ICM, investigating the regulatory role of ferroptosis in the pathological process of ICM and advocating for ferroptosis as a potential novel therapeutic target for ICM based on evidence from the ICM transcriptome.

Construction by artificial intelligence and immunovalidation of hypoallergenic mite allergen Der f 36 vaccine.

Background: The house dust mite (HDM) is widely recognized as the most prevalent allergen in allergic diseases. Allergen-specific immunotherapy (AIT) has been successfully implemented in clinical treatment for HDM. Hypoallergenic B-cell epitope-based vaccine designed by artificial intelligence (AI) represents a significant progression of recombinant hypoallergenic allergen derivatives. Method: The three-dimensional protein structure of Der f 36 was constructed using Alphafold2. AI-based tools were employed to predict B-cell epitopes, which were subsequently verified through IgE-reaction testing. Hypoallergenic Der f 36 was then synthesized, expressed, and purified. The reduced allergenicity was assessed by enzyme-linked immunosorbent assay (ELISA), immunoblotting, and basophil activation test. T-cell response to hypoallergenic Der f 36 and Der f 36 was evaluated based on cytokine expression in the peripheral blood mononuclear cells (PBMCs) of patients. The immunogenicity was evaluated and compared through rabbit immunization with hypoallergenic Der f 36 and Der f 36, respectively. The inhibitory effect of the blocking IgG antibody on the specific IgE-binding activity and basophil activation of Der f 36 allergen was also examined. Results: The final selected non-allergic B-cell epitopes were 25-48, 57-67, 107-112, 142-151, and 176-184. Hypoallergenic Der f 36 showed significant reduction in IgE-binding activity. The competitive inhibition of IgE-binding to Der f 36 was investigated using the hypoallergenic Der f 36, and only 20% inhibition could be achieved, which is greatly reduced when compared with inhibition by Der f 36 (98%). The hypoallergenic Der f 36 exhibited a low basophil-stimulating ratio similar to that of the negative control, and it could induce an increasing level of IFN-γ but not Th2 cytokines IL-5 and IL-13 in PBMCs. The vaccine-specific rabbit blocking IgG antibodies could inhibit the patients' IgE binding and basophil stimulation activity of Derf 36. Conclusion: This study represents the first application of an AI strategy to facilitate the development of a B-cell epitope-based hypoallergenic Der f 36 vaccine, which may become a promising immunotherapy for HDM-allergic patients due to its reduced allergenicity and its high immunogenicity in inducing blocking of IgG.

Artificial intelligence-driven design of the assembled major cat allergen Fel d 1 to improve its spatial folding and IgE-reactivity.

BACKGROUND: Cat-derived allergens are considered as one of the most common causes of allergic diseases worldwide. Fel d 1 is a major cat allergen and plays an important role in immunoglobulin E (IgE)-reaction diagnosis. However, the two separate chains of Fel d 1 exhibited lower IgE-reactivity than its complete molecule of an assembled form, which makes it difficult to efficiently prepare and limits the application of Fel d 1 in molecular diagnosis of cat allergy. METHODS: We first applied artificial intelligence (AI) based tool AlphaFold2 to build the 3-dimensional structures of Fel d 1 with different connection modes between two chains, which were evaluated by ERRAT program and were expressed in Escherichia coli. We then calculated the expression ratios of soluble form/inclusion bodies form of optimized Fel d 1. The Circular Dichroism (CD), High Performance Liquid Chromatography-Size Exclusion Chromatography (HPLC-SEC) and reducing/non-reducing SDS-PAGE were performed to characterize the folding status and dimerization of the optimized fusion Fel d 1. The improvement of specific-IgE reactivity to optimized fusion Fel d 1 was investigated by enzyme linked immunosorbent assay (ELISA). RESULTS: Among several linkers, 2 × GGGGS got the highest scores, with an overall quality factor of 100. The error value of the residues around the junction of 2 × GGGGS was lower than others. It exhibited highest proportion of soluble protein than other Fel d 1 constructs with ERRAT (GGGGS, KK as well as direct fusion Fel d 1). The results of CD and HPLC-SEC showed the consistent folding and dimerization of two fused subunits between the optimized fusion Fel d 1 and previously well-defined direct fusion Fel d 1. The overall IgE-binding absorbance of optimized fusion Fel d 1 tested by ELISA was improved compared with that of the direct fusion Fel d 1. CONCLUSION: We firstly provided an AI-design strategy to optimize the Fel d 1, which could spontaneously fold into its native-like structure without additional refolding process or eukaryotic folding factors. The improved IgE-binding activity and simplified preparation method could greatly facilitate it to be a robust allergen material for molecular diagnosis of cat allergy.

[Clinical comparative study of efficacy of Er:YAG laser for debonding different veneers].

PURPOSE: To compare the debonding time of IPS e.max CAD lithium disilicate glass-ceramic veneers in different thickness and transparency using Er:YAG laser, and evaluate the effect of Er:YAG laser on the surface topography of the veneers and the underlying tooth. METHODS: A total of twelve maxillary first premolar teeth were collected and prepared, then veneers were made by computer aided design and computer aided manufacture(CAD/CAM) system. The veneers were divided into four groups according to different thicknesses and transparency: e.max HT with 0.5 mm and 1.0 mm thickness, e.max LT with 0.5 mm and 1.0 mm thickness. Three veneers of each group were cemented to prepared premolar with resin cement and then stored in normal saline solution at room temperature for 7 days. All veneers were debonded with Er:YAG laser and the debonding time of all-ceramic veneers of all groups was recorded. Scanning electron microscopy(SEM) observation was performed to detect the surface topography of the veneers and the underlying tooth. SPSS 19.0 software package was used for statistical analysis. RESULTS: The debonding time of 1.0 mm-thick groups were longer than 0.5 mm-thick groups. When the veneer thickness was 0.5 mm, the average debonding time of e.max LT group was longer than e.max HT. Consistent with the finding of 0.5 mm, the longer debonding time was found in the e.max LT group of 1.0mm. No cracks and crater structure were found in SEM observation of veneers after Er:YAG laser irradiation. Teeth surface was covered with bonding cement with no signs of ablation or damage of the enamel. CONCLUSIONS: Er:YAG laser can completely debond lithium disilicate glass-ceramic veneers, and the debonding time depends on the transparency and thickness of the veneers. The lower translucent porcelain veneers (e.max LT) and thicker ones (1.0 mm-thick) had a longer debonding time. Moreover, Er:YAG laser does not damage the morphology and topography of the veneer and the teeth surface.