Prediction of intravenous immunoglobulin retreatment in children with Kawasaki disease using models combining lymphocyte subset and cytokine profile in an East Asian cohort.

Objectives: For children with Kawasaki disease (KD) at high risk of developing coronary artery lesions and requiring retreatment with intravenous immunoglobulin (IVIG), the availability of accurate prediction models remains limited because of inconsistent variables and unsatisfactory prediction results. We aimed to construct models to predict patient's probability of IVIG retreatment combining children's individual inflammatory characteristics. Methods: Clinical manifestations and laboratory examinations of 266 children with KD were retrospectively analysed to build a development cohort data set (DC) and a validation cohort data set (VC). In the DC, binary logistic regression analyses were performed using R language. Nomograms and receiver operating curves were plotted. The concordance index (C index), net reclassification index, integrated discrimination improvement index and confusion matrix were applied to evaluate and validate the models. Results: Models_5V and _9V were established. Both contained variables including the percentages of CD8+ T cells, CD4+ T cells, CD3+ T cells, levels of interleukin (IL)-2R and CRP. Model_9V additionally included variables for IL-6, TNF-α, NT-proBNP and sex, with a C index of 0.86 (95% CI 0.79-0.92). When model_9V was compared with model_5V, the NRI and IDI were 0.15 (95% CI 0.01-0.30, P < 0.01) and 0.07 (95% CI 0.02-0.12, P < 0.01). In the VC, the sensitivity, specificity and precision of model_9V were 1, 0.875 and 0.667, while those of model_5V were 0.833, 0.875 and 0.625. Conclusion: Model_9V combined cytokine profiles and lymphocyte subsets with clinical characteristics and was superior to model_5V achieving satisfactory predictive power and providing a novel strategy early to identify patients who needed IVIG retreatment.

HBV DNA polymerase upregulates the transcription of PD-L1 and suppresses T cell activity in hepatocellular carcinoma.

BACKGROUND: In HBV-associated HCC, T cells often exhibit a state of functional exhaustion, which prevents the immune response from rejecting the tumor and allows HCC to progress. Moreover, polymerase-specific T cells exhibit more severe T-cell exhaustion compared to core-specific T cells. However, whether HBV DNA polymerase drives HBV-specific CD8+ T cell exhaustion in HBV-related HCC remains unclear. METHODS: We constructed a Huh7 cell line stably expressing HA-HBV-DNA-Pol and applied co-culture systems to clarify its effect on immune cell function. We also examined how HBV-DNA-Pol modulated PD-L1 expression in HCC cells. In addition, HBV-DNA-Pol transgenic mice were used to elucidate the underlying mechanism of HBV-DNA-Pol/PD-L1 axis-induced T cell exhaustion. RESULTS: Biochemical analysis showed that Huh7 cells overexpressing HBV-DNA-Pol inhibited the proliferation, activation, and cytokine secretion of Jurkat cells and that this effect was dependent on their direct contact. A similar inhibitory effect was observed in an HCC mouse model. PD-L1 was brought to our attention during screening. Our results showed that the overexpression of HBV-DNA-Pol upregulated PD-L1 mRNA and protein expression. PD-L1 antibody blockade reversed the inhibitory effect of Huh7 cells overexpressing HBV-DNA-Pol on Jurkat cells. Mechanistically, HBV-DNA-Pol interacts with PARP1, thereby inhibiting the nuclear translocation of PARP1 and further upregulating PD-L1 expression. CONCLUSIONS: Our findings suggest that HBV-DNA-Pol can act as a regulator of PD-L1 in HCC, thereby directing anti-cancer immune evasion, which further provides a new idea for the clinical treatment of liver cancer.

The Potential Role of Genic-SSRs in Driving Ecological Adaptation Diversity in Caragana Plants.

Caragana, a xerophytic shrub genus widely distributed in northern China, exhibits distinctive geographical substitution patterns and ecological adaptation diversity. This study employed transcriptome sequencing technology to investigate 12 Caragana species, aiming to explore genic-SSR variations in the Caragana transcriptome and identify their role as a driving force for environmental adaptation within the genus. A total of 3666 polymorphic genic-SSRs were identified across different species. The impact of these variations on the expression of related genes was analyzed, revealing a significant linear correlation (p < 0.05) between the length variation of 264 polymorphic genic-SSRs and the expression of associated genes. Additionally, 2424 polymorphic genic-SSRs were located in differentially expressed genes among Caragana species. Through weighted gene co-expression network analysis, the expressions of these genes were correlated with 19 climatic factors and 16 plant functional traits in various habitats. This approach facilitated the identification of biological processes associated with habitat adaptations in the studied Caragana species. Fifty-five core genes related to functional traits and climatic factors were identified, including various transcription factors such as MYB, TCP, ARF, and structural proteins like HSP90, elongation factor TS, and HECT. The roles of these genes in the ecological adaptation diversity of Caragana were discussed. Our study identified specific genomic components and genes in Caragana plants responsive to heterogeneous habitats. The results contribute to advancements in the molecular understanding of their ecological adaptation, lay a foundation for the conservation and development of Caragana germplasm resources, and provide a scientific basis for plant adaptation to global climate change.

HBV DNA polymerase regulates tumor cell glycogen to enhance the malignancy of HCC cells.

BACKGROUND: The essential function of HBV DNA polymerase (HBV-DNA-Pol) is to initiate viral replication by reverse transcription; however, the role of HBV-DNA-Pol in HBV-associated HCC has not been clarified. Glycogen phosphorylase L (PYGL) is a critical regulator of glycogenolysis and is involved in tumorigenesis, including HCC. However, it is unknown whether HBV-DNA-Pol regulates PYGL to contribute to HCC tumorigenesis. METHODS: Bioinformatic analysis, real-time quantitative PCR, western blotting, and oncology functional assays were performed to determine the contribution of HBV-DNA-Pol and PYGL to HCC development and glycolysis. The mechanisms of co-immunoprecipitation and ubiquitination were employed to ascertain how HBV-DNA-Pol upregulated PYGL. RESULTS: Overexpression of HBV-DNA-Pol enhanced HCC progression in vitro and in vivo. Mechanistically, HBV-DNA-Pol interacted with PYGL and increased PYGL protein levels by inhibiting PYGL ubiquitination, which was mediated by the E3 ligase TRIM21. HBV-DNA-Pol competitively impaired the binding of PYGL to TRIM21 due to its stronger binding affinity to TRIM21, suppressing the ubiquitination of PYGL. Moreover, HBV-DNA-Pol promoted glycogen decomposition by upregulating PYGL, which led to an increased flow of glucose into glycolysis, thereby promoting HCC development. CONCLUSIONS: Our study reveals a novel mechanism by which HBV-DNA-Pol promotes HCC by controlling glycogen metabolism in HCC, establishing a direct link between HBV-DNA-Pol and the Warburg effect, thereby providing novel targets for HCC treatment and drug development.

Percutaneous Endoscopic Lumbar Discectomy for Calcified Lumbar Disc Herniation: A Retrospective Cohort Study, Systematic Review and Meta-Analysis.

BACKGROUND: Calcified lumbar disc herniation (CLDH) is a subtype characterized by calcification, leading to increased surgical complexity. Percutaneous endoscopic lumbar discectomy (PELD) is a minimally invasive technique, but its effectiveness and complications in CLDH patients remain to be fully evaluated. OBJECTIVE: To assess the effectiveness and complications of PELD in treating CLDH patients. STUDY DESIGN: A retrospective cohort study combined with a systematic review and meta-analysis. SETTING: Department of Pain Medicine, an affiliated hospital of a university. METHODS: Data from patients who underwent PELD in our department between March 2020 and May 2021 were collected. Forty CLDH patients were included in the study group, and equally matched cases with uncalcified lumbar disc herniation (UCLDH) served as controls. A systematic search was conducted on October 5, 2022, using EMBASE, PubMed, Cochrane Library, the China Biology Medicine disk, the China National Knowledge Infrastructure, and the Wanfang databases, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A random-effects model was used to calculate pooled results. RESULTS: Eighty patients were included in the retrospective cohort, and 41 studies were included in the meta-analysis. Both the retrospective cohort and meta-analysis consistently showed a significant decrease in visual analog scale (VAS) and Oswestry Disability Index (ODI) scores in the CLDH group after the operation. In the retrospective cohort, the excellent or good rate according to the MacNab classification was 85%, with no reported complications. The meta-analysis revealed a pooled excellent or good rate of 91.8% and a low complication rate of 2.9%. Combining the findings from our retrospective cohort and meta-analysis, we observed that the CLDH group had longer operation times and slightly higher postoperative ODI scores compared to the UCLDH group. LIMITATIONS: Small sample size and lack of long-term follow-up in the retrospective cohort, as well as limited inclusion of comparative studies in the meta-analysis. CONCLUSION: PELD is an effective and safe treatment option for CLDH patients. In comparison to UCLDH patients, CLDH patients may experience longer operation times and slightly slower functional recovery than those with UCLDH.

T-cell lymphopenia is associated with an increased infecting risk in children after cardiopulmonary bypass.

BACKGROUND: children who undergo CPB operations are at an elevated risk of infection due to immunosuppression. This study aims to investigate the association between lymphopenia following CPB and early postoperative infection in children. METHODS: A retrospective analysis including 41 children under 2 years old underwent CPB. Among them, 9 subjects had an early postoperative infection, and 32 subjects were period-matched without infection. Inflammatory cytokines, serum CRP and PCT values were measured in plasma, additionally, circulating total leucocyte and lymphocyte subpopulations were counted. RESULTS: Infected subjects exhibited significantly higher levels of inflammatory cytokines, including IL-6, IL-8, IL-10, IL-1ß and TNF-α, than non-infected subjects after CPB. Additionally, lower absolute number of lymphocyte and their subpopulations CD3+ T cells, CD4+ T-helper cells and CD8+cytotoxic T-cells, were observed in infected subjects. The impairment of T-cells Immune was found to be associated with higher levels of inflammatory cytokines IL-10. The ROC demonstrated that the absolute number of CD3+ T-cells <1934/ul, CD4+ T helper cells <1203/ul and CD8+cytotoxic T-cells <327/ul were associated with early postoperative infection. CONCLUSION: Higher levels of inflammatory cytokines resulted in T-cells lymphopenia after CPB, which significantly increasing the risk of postoperative infection in infants and young children. IMPACT: Infection complications after cardiopulmonary bypass (CPB) in pediatric CHD patients are serious issues, identifing the infection from after CPB remains a challenging. CPB can release numerous inflammatory cytokines associated with T cells lymphopenia, which increases the risk of postoperative infection after surgery. Monitoring T cells lymphopenia maybe more beneficial to predict early postoperative infection than C-reactive protein and procalcitonin.

PKCζ phosphorylates VASP to mediate chemotaxis in breast cancer cells.

Breast carcinoma (BC) is one of the most common malignant cancers in females, and metastasis remains the leading cause of death in these patients. Chemotaxis plays an important role in cancer cell metastasis and the mechanism of breast cancer chemotaxis has become a central issue in contemporary research. PKCζ, a member of the atypical PKC family, has been reported to be an essential component of the EGF-stimulated chemotactic signaling pathway. However, the molecular mechanism through which PKCζ regulates chemotaxis remains unclear. Here, we used a proteomic approach to identify PKCζ-interacting proteins in breast cancer cells and identified VASP as a potential binding partner. Intriguingly, stimulation with EGF enhanced this interaction and induced the translocalization of PKCζ and VASP to the cell membrane. Further experiments showed that PKCζ catalyzes the phosphorylation of VASP at Ser157, which is critical for the biological function of VASP in regulating chemotaxis and actin polymerization in breast cancer cells. Furthermore, in PKCζ knockdown BC cells, the enrichment of VASP at the leading edge was reduced, and its interaction with profilin1 was attenuated, thereby reducing the chemotaxis and overall motility of breast cancer cells after EGF treatment. In functional assays, PKCζ promoted chemotaxis and motility of BC cells through VASP. Our findings demonstrate that PKCζ, a new kinase of VASP, plays an important role in promoting breast cancer metastasis and provides a theoretical basis for expanding new approaches to tumor biotherapy.

A nomogram to predict 28-day mortality in neonates with sepsis: a retrospective study based on the MIMIC-III database.

Background: Sepsis is the second-leading cause of death in neonates. We established a predictive nomogram to identify critically ill neonates early and reduce the time to treatment. Methods: It is a retrospective case-control study based on the MIMIC-III database. The study population comprised 924 neonates diagnosed with sepsis. Results: Neonates with sepsis included in the MIMIC-III database were enrolled, including 880 surviving neonates and 44 neonates who died. In the derivation dataset, stepwise regression and the Lasso algorithm were employed to select predictive variables, and the neonatal sequential organ failure assessment score (nSOFA) was calculated simultaneously. Bootstrap resampling was utilized to perform internal validation. The results indicated that the Lasso algorithm displayed superior discrimination, sensitivity, and specificity relative to stepwise regression and nSOFA scores. After 500 bootstrap resampling tests, the area under the receiver operating characteristic curve (AUC) of the Lasso algorithm was 0.912 (95% CI: 0.870-0.977). The nomogram based on the Lasso algorithm outperformed stepwise regression and nSOFA scores in terms of calibration and the clinical net benefit. This nomogram can assist in prognosticating neonatal severe sepsis and aid in guiding clinical practice while concurrently improving patient outcomes. Conclusions: The established nomogram revealed that jaundice, corticosteroid use, weight, serum calcium, inotropes and base excess are all important predictors of 28-day mortality in neonates with sepsis. This nomogram can facilitate the early identification of neonates with severe sepsis. However, it still requires further modification and external validation to make it widely available.

Prognosis and outcome of intrauterine treatment of fetuses with critical congenital heart disease.

BACKGROUND: Intrauterine valvuloplasty is an innovative therapy, which promotes ventricular growth and function in some congenital heart diseases (CHDs). The technique remains challenging and can only be performed in a few centers. This study aimed to assess the feasibility and mid-term outcomes of fetal cardiac intervention (FCI) in fetuses with critical CHD in an experienced tertiary center. METHODS: Five fetal aortic valvuloplasty (FAV) or fetal pulmonary valvuloplasty (FPV) procedures were performed in our fetal heart center between August 2018 and May 2022. Technical success was defined as crossing the aortic or pulmonary valve and balloon inflation, followed by evidence of increased blood flow across the valve and/or new regurgitation. Follow-up clinical records and echocardiography were obtained during the prenatal and postnatal periods. RESULTS: Five fetuses received FAV or FPV, including critical aortic stenosis (n = 2) and pulmonary atresia with intact ventricular septum (n = 3). The mean maternal age was 33.0 ± 2.6 years. The median gestational age (GA) at diagnosis was 24 weeks (range, 22-26 weeks). The median GA at intervention was 29 weeks (range, 28-32 weeks). All five cases underwent successful or partially successful procedures. One patient had pulmonary valve perforation without balloon dilation. No procedure-related deaths or significant complications occurred. However, one neonatal death occurred due to heart and renal failure. The median follow-up period was 29.5 months (range, 8.0-48.0 months). The four surviving patients had achieved biventricular circulation, exhibited improved valve, and ventricular development at the last follow-up visit. CONCLUSION: Intrauterine FCI could be performed safely with good prognosis in critical CHD.

Synergistic effect-triggered fluorescence quenching enables rapid and sensitive detection of alkaline phosphatase.

The development of biosensors mediated by synergistic quenching effect is of great significance for rapid and accurate clinical diagnosis. Hence, we prepared a cyan-emitting fluorescent Si dots for alkaline phosphatase (ALP) detection through the synergistic quenching effect of inner filter effect (IFE) and photo-induced electron transfer (PET). Si dots were prepared by microwave-assisted method, which displayed high quantum yield (28.7%), as well as good physiochemical properties, such as photo-stability, pH stability, and chemical stability. As the hydrolysate of 4-nitrophenyl phosphate disodium salt hexahydrate catalyzed by ALP, both IFE and PET of 4-nitrophenyl to Si dots were used for the turn-off mode detection of ALP. The linear relationships were established between the change of fluorescence intensity and ALP concentration in the range of 0.05 U L-1 to 5.0 U L-1, and 5.0 U L-1 to 80.0 U L-1, respectively. The detection limit was 0.01 U L-1. The synergistic quenching effect caused the turn-off mode detection to be more sensitive, and it can also be used for the accurate detection of ALP in human serum, thereby showing great anti-interference ability in complex environments.

Characteristics and outcomes of fetal ventricular aneurysm and diverticulum: combining the use of a new technique, fetal HQ.

Objectives: Congenital ventricular aneurysms or diverticulum (VA/VD) are rare cardiac anomalies with lack prenatal evaluation data. The present study aimed to provide the prenatal characteristics and outcomes from a tertiary center and the use of new techniques to evaluate the shape and contractility of these fetuses. Methods: Ten fetuses were diagnosed with VA or VD, and 30 control fetuses were enrolled. Fetal echocardiography was performed to make the diagnosis. The prenatal echo characteristics and follow-up data were carefully reviewed. The shape and contractility measurements of the four-chamber view (4CV) and both ventricles were measured and computed using fetal fetal heart quantification (HQ). Results: A total of 10 fetuses were enrolled, including 4 cases of left ventricular diverticulum, 5 cases of left ventricular aneurysm, and 1 case of right ventricular aneurysm (RVA). Four cases chose to terminate the pregnancy. The RVA was associated with a perimembranous ventricular septal defect. Two cases had fetal arrhythmia, and one case had pericardial effusion. After birth, one case underwent surgical resection at five years old. The 4CV global sphericity index (SI) of free-wall located ventricular outpouching (VO) was significantly lower than the apical ones and the control group (p < 0.01). Four of five apical left VOs had significant higher (>95th centile) SI in base segments, and three of four left VOs in the free-wall had significant lower (< 5th centile) SI in the majority of 24 segments. Compared to the control group, the left ventricle (LV) global longitudinal strain, ejection fraction, and fractional area change were significantly decreased (p < 0.01), while the LV cardiac output of the cases was in the normal range. The transverse fraction shortening of the affected segments of ventricles was significantly lower than the other ventricle segments (p < 0.01). Conclusions: Fetal HQ is a promising technique to evaluate the shape and contractility of congenital ventricular aneurysm and diverticulum.

Predictive value of fetal echocardiographic parameters in surgical strategy for Tetralogy of Fallot.

OBJECTIVES: This study aimed to evaluate whether fetal echocardiographic parameters were predictive of the postnatal surgical treatment required for fetuses with Tetralogy of Fallot (TOF). METHODS: The fetal echocardiographic and postnatal clinical data of all cases of prenatal TOF at Xinhua Hospital from 2016 to 2020 were reviewed. Patients were categorized based on the operation type, and cardiac parameters were compared between groups. RESULTS: Of the 37 fetuses assessed, the development of the pulmonary valve annulus (PVA) was significantly poorer in the transannular patch group. Patients with a prenatal PVA z-score (Schneider's method) ≥ -2.645, a PVA z-score (Lee's method) ≥ -2.805, a PVA/aortic valve annulus diameter ratio ≥ .697, and a pulmonary annulus index ≥ .823 were more likely to undergo pulmonary valve-sparing surgery. There was a strong correlation between prenatal and postnatal PVA z-scores. The PVA growth potential was greater in the pulmonary valve-sparing surgery group. CONCLUSIONS: PVA-related parameters evaluated by fetal echocardiography can predict the type of surgical intervention required and are valuable in improving prenatal counseling in fetal cases of TOF.

Precipitation and temperature regulate species diversity, plant coverage and aboveground biomass through opposing mechanisms in large-scale grasslands.

Introduction: Although the relationships between species diversity and aboveground biomass (AGB) are highly debated in grassland ecosystems, it is not well understood how climatic factors influence AGB directly and indirectly via plant coverage and species diversity in large-scale grasslands along a topographic gradient. In doing so, we hypothesized that climatic factors would regulate plant coverage, species diversity and AGB due to maintaining plant metabolic and ecological processes, but the relationship of plant coverage with AGB would be stronger than species diversity due to covering physical niche space. Methods: To test the proposed hypothesis, we collected data for calculations of species richness, evenness, plant coverage and AGB across 123 grassland sites (i.e., the mean of 3 plots in each site) dominated by Leymus chinensis in northern China. We used a structural equation model for linking the direct and indirect effects of topographic slope, mean annual precipitation and temperature on AGB via plant coverage, species richness, and evenness through multiple complex pathways. Results: We found that plant coverage increased AGB, but species evenness declined AGB better than species richness. Topographic slope influenced AGB directly but not indirectly via plant coverage and species diversity, whereas temperature and precipitation increased with increasing topographic slope. Regarding opposing mechanisms, on the one hand, precipitation increased AGB directly and indirectly via plant coverage as compared to species richness and evenness. On the other hand, temperature declined AGB indirectly via plant coverage but increased via species evenness as compared to species richness, whereas the direct effect was negligible. Discussion: Our results show that niche complementarity and selection effects are jointly regulating AGB, but these processes are dependent on climatic factors. Plant coverage promoted the coexistence of species but depended greatly on precipitation and temperature. Our results highlight that precipitation and temperature are two key climatic drivers of species richness, evenness, plant coverage and AGB through complex direct and indirect pathways. Our study suggests that grasslands are sensitive to climate change, i.e., a decline in water availability and an increase in atmospheric heat. We argue that temperature and precipitation should be considered in grassland management for higher productivity in the context of both plant coverage and species diversity which underpin animals and human well-being.

Novel compound heterozygous CCDC40 mutations in a familial case of primary ciliary dyskinesia.

Primary ciliary dyskinesia (PCD) is a rare genetic disorder characterized by motile ciliary dysfunction and impaired ultrastructure. Despite numerous studies, the genetic basis for about 30% of PCD cases remains to be elucidated. Here, we present the identification and functional analysis of two novel mutations in the gene encoding coiled-coil domain-containing protein 40 (CCDC40), which are found in a familial case of PCD. These novel CCDC40 mutations, NM_017950.4: c.2236-2delA and c.2042_2046delTCACA, NP_060420.2: p.(Ile681fs), were identified by whole-exome sequencing (WES). Sanger sequencing was then performed to confirm the WES results and determine the CCDC40 gene sequences of the proband's parents. The c.2042_2046delTCACA mutation disrupts the reading frame of the protein and is therefore predicted to produce a non-functional protein. Using a minigene assay with the pcDNA3.1(+) plasmid, we further investigated the potential pathogenic effects of the c.2236-2delA mutation and found that this mutation leads to formation of a truncated protein via splicing disruption. Thus, in summary, we identified two mutations of the CCDC40 gene that can be considered pathogenic compound heterozygous mutations in a case of familial PCD, thereby expanding the known mutational spectrum of the CCDC40 gene in this disease.

Congenital aortocaval fistula combined with patent ductus arteriosus in an infant: a case report.

Congenital aortocaval fistula (ACF) is a rare cardiac malformation. While it can occur in combination with patent ductus arteriosus (PDA), this has not been reported. In this case, a 1-year-old infant had a heart murmur found in a routine physical examination, and PDA was revealed by transthoracic echocardiography and abdominal ACF was detected by three-dimensional coronary artery computed tomography. Percutaneous interventional therapy, used for ACF and PDA, was performed to occlude the malformation. The patient presented good health without any discomfort at a 1-year follow-up. The percutaneous closure of ACF and PDA with an Amplatzer vascular device can be considered an appropriate option.

Stability and asynchrony of local communities but less so diversity increase regional stability of Inner Mongolian grassland.

Extending knowledge on ecosystem stability to larger spatial scales is urgently needed because present local-scale studies are generally ineffective in guiding management and conservation decisions of an entire region with diverse plant communities. We investigated stability of plant productivity across spatial scales and hierarchical levels of organization and analyzed impacts of dominant species, species diversity, and climatic factors using a multisite survey of Inner Mongolian grassland. We found that regional stability across distant local communities was related to stability and asynchrony of local communities. Using only dominant instead of all-species dynamics explained regional stability almost equally well. The diversity of all or only dominant species had comparatively weak effects on stability and synchrony, whereas a lower mean and higher variation of precipitation destabilized regional and local communities by reducing population stability and synchronizing species dynamics. We demonstrate that, for semi-arid temperate grassland with highly uneven species abundances, the stability of regional communities is increased by stability and asynchrony of local communities and these are more affected by climate rather than species diversity. Reduced amounts and increased variation of precipitation in the future may compromise the sustainable provision of ecosystem services to human well-being in this region.

Expression and characterization of heparinase II with MBP tag from a novel strain, Raoultella NX-TZ-3-15.

The enzymes are biological macromolecules that biocatalyze certain biochemical reactions without undergoing any modification or degradation at the end of the reaction. In this work, we constructed a recombinant novel Raoultella sp. NX-TZ-3-15 strain that produces heparinase with a maltose binding tag to enhance its production and activity. Additionally, MBP-heparinase was purified and its enzymatic capabilities are investigated to determine its industrial application. Moreover, the recombinant plasmid encoding the MBP-heparinase fusion protein was effectively generated and purified to a high purity. According to SDS-PAGE analysis, the MBP-heparinase has a molecular weight of around 70 kDa and the majority of it being soluble with a maximum activity of 5386 U/L. It has also been noted that the three ions of Ca2 + , Co2 + , and Mg2 + can have an effect on heparinase activities, with Mg2 + being the most noticeable, increasing by about 85%, while Cu2 + , Fe2 + , Zn2 + having an inhibitory effect on heparinase activities. Further investigations on the mechanistic action, structural features, and genomes of Raoultella sp. NX-TZ-3-15 heparinase synthesis are required for industrial-scale manufacturing.

Probiotic-Based Bacteriocin: Immunity Supplementation Against Viruses. An Updated Review.

Viral infections are a major cause of severe, fatal diseases worldwide. Recently, these infections have increased due to demanding contextual circumstances, such as environmental changes, increased migration of people and product distribution, rapid demographic changes, and outbreaks of novel viruses, including the COVID-19 outbreak. Internal variables that influence viral immunity have received attention along with these external causes to avert such novel viral outbreaks. The gastrointestinal microbiome (GIM), particularly the present probiotics, plays a vital role in the host immune system by mediating host protective immunity and acting as an immune regulator. Bacteriocins possess numerous health benefits and exhibit antagonistic activity against enteric pathogens and immunobiotics, thereby inhibiting viral infections. Moreover, disrupting the homeostasis of the GIM/host immune system negatively affects viral immunity. The interactions between bacteriocins and infectious viruses, particularly in COVID-19, through improved host immunity and physiology are complex and have not yet been studied, although several studies have proven that bacteriocins influence the outcomes of viral infections. However, the complex transmission to the affected sites and siRNA defense against nuclease digestion lead to challenging clinical trials. Additionally, bacteriocins are well known for their biofunctional properties and underlying mechanisms in the treatment of bacterial and fungal infections. However, few studies have shown the role of probiotics-derived bacteriocin against viral infections. Thus, based on the results of the previous studies, this review lays out a road map for future studies on bacteriocins for treating viral infections.

Euglena gracilis Promotes Lactobacillus Growth and Antioxidants Accumulation as a Potential Next-Generation Prebiotic.

Euglena gracilis, a single-celled microalga with various trophic growth styles under different cultivation conditions, contains nutrients, such as ß-1,3-glucans, essential amino acids, fatty acids, vitamins, and minerals. It has recently attracted attention as a new health food. Among them, ß-1,3-glucans, paramylon of Euglena, is an insoluble dietary fiber and is well known as an immune booster, attenuator of obesity and diabetes, reducer of acute liver injury, and suppressor of atopic dermatitis, and other chronic inflammatory disorders. Recently, evidence has appeared for the positive health effects of foods, food ingredients, or biochemical compounds derived from several other microalgae, such as Chlorella, Spirulina, Dunaliella, Phaeodactylum, and Pavlova. Until most recently, the prebiotic activity of Euglena and paramylon was reported. Emerging prospects of microalgae as prebiotics were well summarized, but the mechanisms behind the bacterial growth promotion by microalgae are not elucidated yet. Thus, we evaluated the prebiotic prospects of both autotrophic and heterotrophic Euglena on six different Lactobacillus. What's more, the stimulated mechanism was revealed by bacterial culture medium metabolomic analysis. This study could widen the knowledge about the prebiotic activity of Euglena as a next-generation prebiotic and other microalgae-derived compounds as potential health foods.

Cloning and Expression of Heparinase Gene from a Novel Strain Raoultella NX-TZ-3-15.

Heparin is a class of highly sulfated, acidic, linear, and complex polysaccharide that belongs to the heparin/heparan sulfate (HS) glycosaminoglycans family. Enzymatic depolymerization of heparin by heparinases is a promising strategy for the production of ultra-low molecular weight heparins (ULMWHs) as anticoagulants. In the present study, a novel heparinase-producing strain Raoultella NX-TZ-3-15 was isolated and identified from soil samples. Herein, the heparinase gene MBP-H1 was cloned to the pBENT vector to enable expression in Escherichia coli. The optimized conditions made the activity of recombinant heparinase reach the highest level (2140 U/L). The overexpressed MBP-H1 was purified by affinity chromatography and a purity of more than 90% was obtained. The condition for biocatalysis was also optimized and three metal ions Ca2+, Co2+, and Mg2+ were utilized to activate the reaction. In addition, the kinetics regarding the new fusion heparinase was also determined with a Vm value of 11.29 µmol/min and a Km value of 31.2 µmol/L. In short, due to excellent Km and Vmax, the recombinant enzyme has great potential to be used in the clinic in medicine and industrial production of low or ultra-low molecule weight heparin.