Molecular evolution of Phytocyanin gene and analysis of expression at different coloring periods in apple (Malus domestica).

BACKGROUND: PC (phytocyanin) is a class of copper-containing electron transfer proteins closely related to plant photosynthesis, abiotic stress responses growth and development in plants, and regulation of the expression of some flavonoids and phenylpropanoids, etc., however, compared with other plants, the PC gene family has not been systematically characterized in apple. RESULTS: A total of 59 MdPC gene members unevenly distributed across 12 chromosomes were identified at the genome-wide level. The proteins of the MdPC family were classified into four subfamilies based on differences in copper binding sites and glycosylation sites: Apple Early nodulin-like proteins (MdENODLs), Apple Uclacyanin-like proteins (MdUCLs), Apple Stellacyanin-like proteins (MdSCLs), and Apple Plantacyanin-like proteins (MdPLCLs). Some MdPC members with similar gene structures and conserved motifs belong to the same group or subfamily. The internal collinearity analysis revealed 14 collinearity gene pairs among members of the apple MdPC gene. Interspecific collinearity analysis showed that apple had 31 and 35 homologous gene pairs with strawberry and grape, respectively. Selection pressure analysis indicated that the MdPC gene was under purifying selection. Prediction of protein interactions showed that MdPC family members interacted strongly with the Nad3 protein. GO annotation results indicated that the MdPC gene also regulated the biosynthesis of phenylpropanoids. Chip data analysis showed that (MdSCL3, MdSCL7 and MdENODL27) were highly expressed in mature fruits and peels. Many cis-regulatory elements related to light response, phytohormones, abiotic stresses and flavonoid biosynthetic genes regulation were identified 2000 bp upstream of the promoter of the MdPC gene, and qRT-PCR results showed that gene members in Group IV (MdSCL1/3, MdENODL27) were up-regulated at all five stages of apple coloring, but the highest expression was observed at the DAF13 (day after fruit bag removal) stage. The gene members in Group II (MdUCL9, MdPLCL3) showed down-regulated or lower expression in the first four stages of apple coloring but up-regulated and highest expression in the DAF 21 stage. CONCLUSION: Herein, one objective of these findings is to provide valuable information for understanding the structure, molecular evolution, and expression pattern of the MdPC gene, another major objective in this study was designed to lay the groundwork for further research on the molecular mechanism of PC gene regulation of apple fruit coloration.

The asymmetric expression of plasma membrane H+-ATPase family genes in response to pulvinus-driven leaf phototropism movement in Vitis vinifera.

Phototropism movement is crucial for plants to adapt to various environmental changes. Plant P-type H+-ATPase (HA) plays diverse roles in signal transduction during cell expansion, regulation of cellular osmotic potential and stomatal opening, and circadian movement. Despite numerous studies on the genome-wide analysis of Vitis vinifera, no research has been done on the P-type H+-ATPase family genes, especially concerning pulvinus-driven leaf movement. In this study, 55 VvHAs were identified and classified into nine distinct subgroups (1 to 9). Gene members within the same subgroups exhibit similar features in motif, intron/exon, and protein tertiary structures. Furthermore, four pairs of genes were derived by segmental duplication in grapes. Cis-acting element analysis identified numerous light/circadian-related elements in the promoters of VvHAs. qRT-PCR analysis showed that several genes of subgroup 7 were highly expressed in leaves and pulvinus during leaf movement, especially VvHA14, VvHA15, VvHA16, VvHA19, VvHA51, VvHA52, and VvHA54. Additionally, we also found that the VvHAs genes were asymmetrically expressed on both sides of the extensor and flexor cell of the motor organ, the pulvinus. The expression of VvHAs family genes in extensor cells was significantly higher than that in flexor cells. Overall, this study serves as a foundation for further investigations into the functions of VvHAs and contributes to the complex mechanisms underlying grapevine pulvinus growth and development.

Integrating genetic analysis of germplasm wealth for enhanced selection and improvement in olive (Olea europaea L.): insights from leaves.

KEY MESSAGE: High-throughput next-generation sequencing of 161 olive germplas. 33 samples were selected as core olive germplasm and Fingerprints were constructed. After GWAS analysis of olive leaf shape, 14 candidate genes were localized. Olive (Olea europaea L.) has been introduced to China since the 1960s. After a prolonged period of variation and domestication, there is a lack of comprehensive research on its genetics. The olive oil directly extracted from Olea europaea L. is recognized as 'liquid gold', nevertheless, people constantly overlook the valuable wealth of olive leaves. High-throughput next-generation sequencing was performed on 161 olive germplasm to analyze the kinship, genetic structure and diversity of olives, and the core germplasm of olives were selected and fingerprints were constructed. Meanwhile, Genome-wide association analysis (GWAS) was performed to locate the gene for regulating olive leaf shape. Herein, the results parsed that most of the Chinese olive germplasm was more closely related to the Italian germplasm. A wealth of hybridized germplasm possessed high genetic diversity and had the potential to be used as superior parental material for olive germplasm. A total of 33 samples were selected and characterized as core germplasm of olive and Fingerprints were also constructed. A total of 14 candidate genes were localized after GWAS analysis of four olive leaf shape phenotypes, including leaf shape, leaf curvature shape, leaf tip and leaf base shape. Collectively, this study revealed the genetic basis of olives in China and also succeeded in constructing the core germplasm that stands for the genetic diversity of olives, which can contribute to the scientific and effective collection and preservation of olive germplasm resources, and provide a scientific basis for the in-depth excavation and utilization of genes regulating olive leaf shape.

Shading Treatment Reduces Grape Sugar Content by Suppressing Photosynthesis-Antenna Protein Pathway Gene Expression in Grape Berries.

To explore the impact of shade treatment on grape berries, 'Marselan' grape berries were bagged under different light transmission rates (100% (CK), 75% (A), 50% (B), 25% (C), 0% (D)). It was observed that this treatment delayed the ripening of the grape berries. The individual weight of the grape berries, as well as the content of fructose, glucose, soluble sugars, and organic acids in the berries, was measured at 90, 100, and 125 days after flowering (DAF90, DAF100, DAF125). The results revealed that shading treatment reduced the sugar content in grape berries; the levels of fructose and glucose were higher in the CK treatment compared to the other treatments, and they increased with the duration of the shading treatment. Conversely, the sucrose content exhibited the opposite trend. Additionally, as the weight of the grape berries increased, the content of soluble solids and soluble sugars in the berries also increased, while the titratable acidity decreased. Furthermore, 16 differentially expressed genes (DEGs) were identified in the photosynthesis-antenna protein pathway from the transcriptome sequencing data. Correlation analysis revealed that the expression levels of genes VIT_08s0007g02190 (Lhcb4) and VIT_15s0024g00040 (Lhca3) were positively correlated with sugar content in the berries at DAF100, but negatively correlated at DAF125. qRT-PCR results confirmed the correlation analysis. This indicates that shading grape clusters inhibits the expression of genes in the photosynthesis-antenna protein pathway in the grape berries, leading to a decrease in sugar content. This finding contributes to a deeper understanding of the impact mechanisms of grape cluster shading on berry quality, providing important scientific grounds for improving grape berry quality.

Mechanism of the Pulvinus-Driven Leaf Movement: An Overview.

Leaf movement is a manifestation of plant response to the changing internal and external environment, aiming to optimize plant growth and development. Leaf movement is usually driven by a specialized motor organ, the pulvinus, and this movement is associated with different changes in volume and expansion on the two sides of the pulvinus. Blue light, auxin, GA, H+-ATPase, K+, Cl-, Ca2+, actin, and aquaporin collectively influence the changes in water flux in the tissue of the extensor and flexor of the pulvinus to establish a turgor pressure difference, thereby controlling leaf movement. However, how these factors regulate the multicellular motility of the pulvinus tissues in a species remains obscure. In addition, model plants such as Medicago truncatula, Mimosa pudica, and Samanea saman have been used to study pulvinus-driven leaf movement, showing a similarity in their pulvinus movement mechanisms. In this review, we summarize past research findings from the three model plants, and using Medicago truncatula as an example, suggest that genes regulating pulvinus movement are also involved in regulating plant growth and development. We also propose a model in which the variation of ion flux and water flux are critical steps to pulvinus movement and highlight questions for future research.

[A unicenter real-world study of the correlation factors for complete clinical response in idiopathic inflammatory myopathies].

OBJECTIVE: To investigate the correlation factors of complete clinical response in idiopathic inflammatory myopathies (IIMs) patients receiving conventional treatment. METHODS: Patients diagnosed with IIMs hospitalized in Peking University People's Hospital from January 2000 to June 2023 were included. The correlation factors of complete clinical response to conventional treatment were identified by analyzing the clinical characteristics, laboratory features, peripheral blood lymphocytes, immunological indicators, and therapeutic drugs. RESULTS: Among the 635 patients included, 518 patients finished the follow-up, with an average time of 36.8 months. The total complete clinical response rate of IIMs was 50.0% (259/518). The complete clinical response rate of dermatomyositis (DM), anti-synthetase syndrome (ASS) and immune-mediated necrotizing myopathy (IMNM) were 53.5%, 48.9% and 39.0%, respectively. Fever (P=0.002) and rapid progressive interstitial lung disease (RP-ILD) (P=0.014) were observed much more frequently in non-complete clinical response group than in complete clinical response group. The aspartate transaminase (AST), lactate dehydrogenase (LDH), D-dimer, erythrocyte sedimentation rate (ESR), C-reaction protein (CRP) and serum ferritin were significantly higher in non-complete clinical response group as compared with complete clinical response group. As for the treatment, the percentage of glucocorticoid received and intravenous immunoglobin (IVIG) were significantly higher in non-complete clinical response group than in complete clinical response group. Risk factor analysis showed that IMNM subtype (P=0.007), interstitial lung disease (ILD) (P=0.001), eleva-ted AST (P=0.012), elevated serum ferritin (P=0.016) and decreased count of CD4+T cells in peripheral blood (P=0.004) might be the risk factors for IIMs non-complete clinical response. CONCLUSION: The total complete clinical response rate of IIMs is low, especially for IMNM subtype. More effective intervention should be administered to patients with ILD, elevated AST, elevated serum ferritin or decreased count of CD4+T cells at disease onset.

[Low disease activity and remission status of systemic lupus erythematosus in a real-world study].

OBJECTIVE: To investigate the rates of low disease activity and clinical remission in patients with systemic lupus erythematosus (SLE) in a real-world setting, and to analyze the related factors of low disease activity and clinical remission. METHODS: One thousand patients with SLE were enrolled from 11 teaching hospitals. Demographic, clinical and laboratory data, as well as treatment regimes were collec-ted by self-completed questionnaire. The rates of low disease activity and remission were calculated based on the lupus low disease activity state (LLDAS) and definitions of remission in SLE (DORIS). Charac-teristics of patients with LLDAS and DORIS were analyzed. Multivariate Logistic regression analysis was used to evaluate the related factors of LLDAS and DORIS remission. RESULTS: 20.7% of patients met the criteria of LLDAS, while 10.4% of patients achieved remission defined by DORIS. Patients who met LLDAS or DORIS remission had significantly higher proportion of patients with high income and longer disease duration, compared with non-remission group. Moreover, the rates of anemia, creatinine elevation, increased erythrocyte sedimentation rate (ESR) and hypoalbuminemia was significantly lower in the LLDAS or DORIS group than in the non-remission group. Patients who received hydroxychloroquine for more than 12 months or immunosuppressant therapy for no less than 6 months earned higher rates of LLDAS and DORIS remission. The results of Logistic regression analysis showed that increased ESR, positive anti-dsDNA antibodies, low level of complement (C3 and C4), proteinuria, low household income were negatively related with LLDAS and DORIS remission. However, hydroxychloroquine usage for longer than 12 months were positively related with LLDAS and DORIS remission. CONCLUSION: LLDAS and DORIS remission of SLE patients remain to be improved. Treatment-to-target strategy and standar-dized application of hydroxychloroquine and immunosuppressants in SLE are recommended.

Dynamics of T follicular helper cells in patients with rheumatic diseases and subsequent antibody responses in a three-dose immunization regimen of CoronaVac.

Given increased acceptance of the CoronaVac, there is an unmet need to assess the safety and immunogenic changes of CoronaVac in patients with rheumatic diseases (RD). Here we comprehensively analysed humoral and cellular responses in patient with RD after a three-dose immunization regimen of CoronaVac. RD patients with stable condition and/or low disease activity (n = 40) or healthy controls (n = 40) were assigned in a 1:1 ratio to receive CoronaVac (Sinovac). The prevalence of anti-receptor binding domain (RBD) antibodies and neutralizing antibodies was similar between healthy control (HC) and RD patients after the second and the third vaccination. However, the titers of anti-RBD IgG and neutralizing antibodies were significantly lower in RD patients compared to HCs (p < 0.05), which was associated with an impaired T follicular helper (Tfh) cell response. Among RD patients, those who generated an antibody response displayed a significantly higher Tfh cells compared to those who failed after the first and the second vaccination (p < 0.05). Interestingly, subjects with a negative serological response displayed a similar Tfh memory response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-derived peptides as their anti-RBD IgG positive counterpart, and all (4/4) of the non-responders in HCs, and 62.5% (5/8) of the non-responders in patients with RD displayed a positive serological response following the third dose. No serious adverse events were observed. In conclusion, our findings support SARS-CoV-2 vaccination in patients with RD with stable and/or low disease activity. The impaired ability in generating vaccine-specific antibodies in patients with RD was associated with a reduction in Tfh cells induction. The window of vaccination times still needs to be explored in future studies. Clinical trial registration: This trial was registered with ChiCTR2100049138.

Low-dose IL-2 therapy invigorates CD8+ T cells for viral control in systemic lupus erythematosus.

Autoimmune diseases are often treated by glucocorticoids and immunosuppressive drugs that could increase the risk for infection, which in turn deteriorate disease and cause mortality. Low-dose IL-2 (Ld-IL2) therapy emerges as a new treatment for a wide range of autoimmune diseases. To examine its influence on infection, we retrospectively studied 665 patients with systemic lupus erythematosus (SLE) including about one third receiving Ld-IL2 therapy, where Ld-IL2 therapy was found beneficial in reducing the incidence of infections. In line with this clinical observation, IL-2 treatment accelerated viral clearance in mice infected with influenza A virus or lymphocytic choriomeningitis virus (LCMV). Noticeably, despite enhancing anti-viral immunity in LCMV infection, IL-2 treatment exacerbated CD8+ T cell-mediated immunopathology. In summary, Ld-IL2 therapy reduced the risk of infections in SLE patients and enhanced the control of viral infection, but caution should be taken to avoid potential CD8+ T cell-mediated immunopathology.

Identification and Expression Analysis of the SKP1-Like Gene Family under Phytohormone and Abiotic Stresses in Apple (Malus domestica).

Ubiquitination participates in plant hormone signaling and stress response to adversity. SKP1-Like, a core component of the SCF (Skp1-Cullin-F-box) complex, is the final step in catalyzing the ubiquitin-mediated protein degradation pathway. However, the SKP1-Like gene family has not been well characterized in response to apple abiotic stresses and hormonal treatments. This study revealed that 17 MdSKP1-Like gene family members with the conserved domain of SKP1 were identified in apples and were unevenly distributed on eight chromosomes. The MdSKP1-Like genes located on chromosomes 1, 10, and 15 were highly homologous. The MdSKP1-like genes were divided into three subfamilies according to the evolutionary affinities of monocotyledons and dicotyledons. MdSKP1-like members of the same group or subfamily show some similarity in gene structure and conserved motifs. The predicted results of protein interactions showed that members of the MdSKP1-like family have strong interactions with members of the F-Box family of proteins. A selection pressure analysis showed that MdSKP1-Like genes were in purifying selection. A chip data analysis showed that MdSKP1-like14 and MdSKP1-like15 were higher in flowers, whereas MdSKP1-like3 was higher in fruits. The upstream cis-elements of MdSKP1-Like genes contained a variety of elements related to light regulation, drought, low temperature, and many hormone response elements, etc. Meanwhile, qRT-PCR also confirmed that the MdSKP1-Like gene is indeed involved in the response of the apple to hormonal and abiotic stress treatments. This research provides evidence for regulating MdSKP1-Like gene expression in response to hormonal and abiotic stresses to improve apple stress resistance.

[Significance of anti-Jo-1 antibody's clinical stratification in idiopathic inflammatory myopathy and disease spectrum].

OBJECTIVE: To investigate the significance of anti-histidyl tRNA synthetase (Jo-1) antibody in idiopathic inflammatory myopathies (IIM) and its diseases spectrum. METHODS: We enrolled all the patients who were tested positive for anti-Jo-1 antibody by immunoblotting in Peking University People's Hospital between 2016 and 2022. And the patients diagnosed with anti-synthetase antibody syndrome (ASS) with negative serum anti-Jo-1 antibody were enrolled as controls. We analyzed the basic information, clinical characteristics, and various inflammatory and immunological indicators of the patients at the onset of illness. RESULTS: A total of 165 patients with positive anti-Jo-1 antibody were enrolled in this study. Among them, 80.5% were diagnosed with connective tissue disease. And 57.6% (95/165) were diagnosed with IIM, including ASS (84/165, 50.9%), immune-mediated necrotizing myopathy (7/165, 4.2%) and dermatomyositis (4/165, 2.4%). There were 23.0% (38/165) diagnosed with other connective tissue disease, mainly including rheumatoid arthritis (11/165, 6.7%), undifferentiated connective tissue disease (5/165, 3.0%), interstitial pneumonia with autoimmune features (5/165, 3.0%), undifferentiated arthritis (4/165, 2.4%), Sjögren's syndrome (3/165, 1.8%), systemic lupus erythematosus (3/165, 1.8%), systemic vasculitis (3/165, 1.8%), and so on. Other cases included 3 (1.8%) malignant tumor patients, 4 (2.4%) infectious cases and so on. The diagnoses were not clear in 9.1% (15 /165) of the cohort. In the analysis of ASS subgroups, the group with positive serum anti-Jo-1 antibody had a younger age of onset than those with negative serum anti-Jo-1 antibody (49.9 years vs. 55.0 years, P=0.026). Clinical manifestations of arthritis (60.7% vs. 33.3%, P=0.002) and myalgia (47.1% vs. 22.2%, P=0.004) were more common in the ASS patients with positive anti-Jo-1 antibody. With the increase of anti-Jo-1 antibody titer, the incidence of the manifestations of arthritis, mechanic hands, Gottron sign and Raynaud phenomenon increased, and the proportion of abnormal creatine kinase and α-hydroxybutyric dehydrogenase index increased in the ASS patients. The incidence of myalgia and myasthenia were significantly more common in this cohort when anti-Jo-1 antibody-positive ASS patients were positive for one and more myositis specific antibodies/myositis associated autoantibodies (P < 0.05). CONCLUSION: The disease spectrum in patients with positive serum anti-Jo-1 antibody includes a variety of diseases, mainly ASS. And anti-Jo-1 antibody can also be found in many connective tissue diseases, malignant tumor, infection and so on.

Efficacy and safety of low-dose IL-2 in the treatment of systemic lupus erythematosus: a randomised, double-blind, placebo-controlled trial.

OBJECTIVES: Open-labelled clinical trials suggested that low-dose IL-2 might be effective in treatment of systemic lupus erythematosus (SLE). A double-blind and placebo-controlled trial is required to formally evaluate the safety and efficacy of low-dose IL-2 therapy. METHODS: A randomised, double-blind and placebo-controlled clinical trial was designed to treat 60 patients with active SLE. These patients received either IL-2 (n=30) or placebo (n=30) with standard treatment for 12 weeks, and were followed up for additional 12 weeks. IL-2 at a dose of 1 million IU or placebo was administered subcutaneously every other day for 2 weeks and followed by a 2-week break as one treatment cycle. The primary endpoint was the SLE Responder Index-4 (SRI-4) at week 12. The secondary endpoints were other clinical responses, safety and dynamics of immune cell subsets. RESULTS: At week 12, the SRI-4 response rates were 55.17% and 30.00% for IL-2 and placebo, respectively (p=0.052). At week 24, the SRI-4 response rate of IL-2 group was 65.52%, compared with 36.67% of the placebo group (p=0.027). The primary endpoint was not met at week 12. Low-dose IL-2 treatment resulted in 53.85% (7/13) complete remission in patients with lupus nephritis, compared with 16.67% (2/12) in the placebo group (p=0.036). No serious infection was observed in the IL-2 group, but two in placebo group. Besides expansion of regulatory T cells, low-dose IL-2 may also sustain cellular immunity with enhanced natural killer cells. CONCLUSIONS: Low-dose IL-2 might be effective and tolerated in treatment of SLE. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Registries (NCT02465580 and NCT02932137).

Expression analysis of the apple HSP70 gene family in abiotic stress and phytohormones and expression validation of candidate MdHSP70 genes.

Heat shock protein 70 (HSP70) is one kind of molecular chaperones which are widely found in organisms, and its members are highly conserved among each other, with important roles in plant growth and development. In this study, 56 HSP70 genes were identified from the apple genome database. Analysis of gene duplication events showed that tandem and segmental duplication events play an important role in promoting the amplification of the MdHSP70 gene family. Collinearity analysis showed that HSP70 family members of apple were more closely related to HSP70 family members of Arabidopsis, tomato and soybean. The promoter region of the apple HSP70 genes contains a large number of cis-acting elements in response to hormones and stress. Tissue-specific expression analysis showed that some of the genes were associated with various stages of the apple growth process. Codon preference analysis showed small differences between codon bases 1 and 3 in the apple HSP70 genome, and the codon base composition had a small effect on codon usage preference. The multiple expression patterns of the MdHSP70 gene suggested that MdHSP70 gene members play important roles in growth and development and in response to hormonal and abiotic stresses. The yeast two-hybrid (Y2H) demonstrated that MdHSP70-53 interacts with MdDVH24_032563. The qRT-PCR analysis showed that most MdHSP70 members' hormonal and abiotic stresses (MdHSP70-6, MdHSP70-26 and MdHSP70-45) appeared to be highly expressed. To further elucidate the function of MdHSP70 (6, 26, 45), we introduced them into tobacco to confirm subcellular locations and noted that these genes are located in the cytoplasm and cell membrane. This study serves as a theoretical basis for further studies of the MdHSP70 gene and helps to further investigate the functional characterization of MdHSP70 gene.

Characteristics of patients with initial diagnosis of systemic lupus erythematosus in emergency department and their outcomes: a retrospective single-center study.

STUDY OBJECTIVE: This study aims to investigate the characteristics of patients with an initial diagnosis of systemic lupus erythematosus (SLE) in an emergency department (ED) and their outcomes. METHODS: A total of 147 SLE patients (119 females and 28 males, mean age 26 ± 19 years) who visited the ED of the Peking University People's Hospital between January 2017 and June 2022 were enrolled in the study. Data on demographic information, clinical characteristics, comorbidities, therapy, and outcomes were collected. RESULTS: Most patients visit ED because of symptoms related to SLE (74.8%, 110/147). The remaining 37 patients (25.2%) visited ED due to infection (43.2%, 16/37), gastrointestinal bleeding (10.8%, 4/37), coronary heart or cerebrovascular disease (18.9%, 7/37), macrophage activation syndrome or thrombotic microangiopathy (18.9%, 7/37), leukemia (5.4%, 2/37), and hepatic encephalopathy (2.7%, 1/37). Of the patients, 54.4% (80/147) were first diagnosed with SLE at the time of their ED visit. Thrombocytopenia events occurred significantly more frequently in this group of patients (OR 3.664, 95% CI 1.586-8.464, p = 0.002). Pulse steroid therapy was administered to 32.5% (26/80) of the patients with an initial diagnosis of SLE, and 26.3% (21/80) of these patients also received IVIG therapy during their ED visit. SLEDAI scores were significantly decreased after 6 months of therapy. The rate of mortality was 6.8% (10/147) in the 6-month follow-up period, and all the ten deaths happened in patients with disease-established SLE. The main causes of death were infections (two patients) and SLE flare (four patients). CONCLUSION: Understanding disease patterns can contribute to physicians providing accurate diagnosis and efficient care for SLE patients in ED. Key Points • Systemic lupus erythematosus, a complex autoimmune disorder, can have either a chronic or a relapsing and remitting disease course. The disease can involve acute events or severe comorbidities, and frequent visits to the emergency department (ED) are inevitable. • It is essential to better understand which comorbidities can lead to emergency department visits. Accurate clinical diagnosis and appropriate interventions from ED physicians can have a strong impact on the prognosis of the disease. • Hematologic compromise attributed to SLE flare is the most common reason for ED visits. Owing to aggressive treatments, the clinical outcomes in patients with initial diagnosis of SLE have improved notably. • Our study highlights that early recognition and appropriate management of SLE-related conditions and other comorbidity in ED are crucial.

Finely ordered intracellular domain harbors an allosteric site to modulate physiopathological function of P2X3 receptors.

P2X receptors, a subfamily of ligand-gated ion channels activated by extracellular ATP, are implicated in various physiopathological processes, including inflammation, pain perception, and immune and respiratory regulations. Structural determinations using crystallography and cryo-EM have revealed that the extracellular three-dimensional architectures of different P2X subtypes across various species are remarkably identical, greatly advancing our understanding of P2X activation mechanisms. However, structural studies yield paradoxical architectures of the intracellular domain (ICD) of different subtypes (e.g., P2X3 and P2X7) at the apo state, and the role of the ICD in P2X functional regulation remains unclear. Here, we propose that the P2X3 receptor's ICD has an apo state conformation similar to the open state but with a less tense architecture, containing allosteric sites that influence P2X3's physiological and pathological roles. Using covalent occupancy, engineered disulfide bonds and voltage-clamp fluorometry, we suggested that the ICD can undergo coordinated motions with the transmembrane domain of P2X3, thereby facilitating channel activation. Additionally, we identified a novel P2X3 enhancer, PSFL77, and uncovered its potential allosteric site located in the 1α3ß domain of the ICD. PSFL77 modulated pain perception in P2rx3+/+, but not in P2rx3-/-, mice, indicating that the 1α3ß, a "tunable" region implicated in the regulation of P2X3 functions. Thus, when P2X3 is in its apo state, its ICD architecture is fairly ordered rather than an unstructured outward folding, enabling allosteric modulation of the signaling of P2X3 receptors.

Heparin-mediated fluorescence anisotropy assay of antithrombin based on polyethyleneimine capped Mn-doped ZnS quantum dots.

We presented a homogeneous heparin-mediated fluorescence anisotropy (FA) assay of antithrombin (AT) based on long-lived luminescent polyethyleneimine capped Mn-doped ZnS (PEI-Mn-ZnS) QDs. The PEI-Mn-ZnS QDs with long lifetime luminescence at 585 nm displayed a very low background of FA value, which was very helpful for FA assaying of large molecules. The medium heparin was crucial for AT determination, and different heparin amounts resulted in different linear range of detection and sensitivity. For example, the limit of detection (LOD) of 0.9 nM AT with a detection linear range from 8.6 nM to 21.5 nM was found when the heparin concentration was 75 µM. The proposed method also exhibited high selectivity over the coexisting or related proteins such as human serum albumin and thrombin.

Oil structuring from porous starch to powdered oil: Role of multi-scale structure in the oil adsorption and distribution.

Oil structuring from porous starch is a potential alternative for the industrial production of powdered oil, but their relationship between starch multi-scale structure and oil adsorption characteristics was not clear. This study compared the role of multi-scale structure of porous starch (PS) prepared by normal and waxy maize starch in the oil adsorption. Waxy maize porous starch exhibited higher oil adsorption capacity (32.43 %-98.71 %) and more oil distributed on the surface of granules than normal maize porous starch, resulting from the more pores, larger specific surface area (1.01-1.53 m2/g), and pore size (8.45-9.32 nm). The enzymolysis time of native starch dominated oil distribution, leading to different granule adhesion and aggregation state. Pearson correlation analysis further showed oil adsorption capacity was negatively correlated with particle size, but positively correlated with enzymolysis rate and specific surface area of PS. The formation of powdered oil was mainly through the physical adsorption, including surface adsorption and pore adsorption. These findings could provide a promising route for the preparation of powdered oil with controlled multi-scale structure of PS.

Aberrant Immune Features after Recovery from COVID-19 in Patients with Systemic Lupus Erythematosus and Other Autoimmune Diseases.

Considering the large number of individuals who have already been infected and may have reinfection, the post-infection effects of COVID-19 are of great importance for clinical practice and predicting disease trends. However, our understanding of the potential long-term effects, particularly on immunity, after recovering from COVID-19 remains limited. The aim of this study was to investigate the abnormal immunological factors that contribute to the prolonged immunological effects of COVID-19. Two groups of patients were enrolled in the study, including 11 individuals with various autoimmune diseases (AIDs) and 16 patients diagnosed with systemic lupus erythematosus (SLE). Detailed clinical symptoms were closely monitored, and peripheral mononuclear cells were analyzed using flow cytometry. The clinical status was evaluated using the SLE Disease Activity Index (SLEDAI) and the Clinical Global Impressions (CGI) index. The proportions of follicular T helper cells (Tfh) exhibited significant increases in both cohorts (AID: p = 0.03; SLE: p = 0.0008). Conversely, the percentages of Foxp3+ and CD4+ regulatory T cells (Treg) were reduced in patients following COVID-19 infection (AID: p = 0.009, 0.05, resp.; SLE: p = 0.02, 0.0009, resp.). The percentages of Th2 and Th17 cells were significantly increased in SLE patients (p < 0.05). Exacerbated conditions were observed in SLE patients two months after infection (SLEDAI, p < 0.05). Our findings show that COVID-19 infection increases Tfh cells and decreases Treg cells in patients of AIDs, worsening pathogenetic immune status in post-recovery populations.

Enhanced stability and controlled release of menthol using a ß-cyclodextrin metal-organic framework.

Menthol inclusion complexes (ICs) have addressed a range of opportunities in food applications due to their volatile resistance. However, previous protocols used for their synthesis give low yields and high industrial application costs. In the present investigation, metal-organic frameworks based on ß-cyclodextrin (ß-CD-MOF) have been prepared for the molecular encapsulation of menthol. Menthol/ß-CD-MOF-IC was synthesized under the optimized parameters, after which release behavior was studied. In this optimized manner, a higher menthol capacity was obtained in which the menthol content and encapsulation efficiency were 27.1 and 30.6%, respectively. Compared with menthol/ß-CD-IC, menthol/ß-CD-MOF-IC is resistant to high temperature, but sensitive to moisture. In a simulated oral release experiment, the rate of menthol release from different samples followed the order of: pure menthol > ß-CD > ß-CD-MOF, which can be attributed to two mechanisms: non-specific binding and site preference. We propose that ß-CD-MOF can be used as a promising delivery system for aroma compounds.

A Rare Case of Neurosarcoidosis Overlapped with Sjogren's Syndrome.

The coexisting of sarcoidosis and Sjögren's syndrome (SS) has long been neglected since sarcoidosis is considered as an exclusion criterion for SS. We described a 55-year-old woman, who was diagnosed with coexisting neurosarcoidosis and Sjögren's syndrome for 16 years. She presented with erythema nodosum, progressive sensory and motor impairment of the extremities, dry mouth, and dry eyes. High-resolution computed tomography (HRCT) of the chest showed symmetrical pulmonary micronodules, interstitial changes, and enlarged mediastinal lymph nodes. Spine magnetic resonance imaging (MRI) showed syringomyelia and thickening of the T3-9 spinal cord. She was with positive ANA and anti-SSA antibodies, impaired function of the lacrimal, salivary gland and renal tubules. Biopsy of skin and lung nodules revealed non-caseous granuloma. Salivary gland biopsy showed focal lymphocyte infiltration. Classification criteria for sarcoidosis and Sjogren's syndrome were fulfilled in this patient based on clinical and laboratory features. This case extends our understanding of overlapped Sjogren's syndrome with sarcoidosis and provides a referential value for clinical diagnosis.