A novel cellulolytic/xylanolytic SbAA14 from Sordaria brevicollis with a branched chain preference and its synergistic effects with glycoside hydrolases on lignocellulose

In this study, the novel auxiliary activity (AA) family 14 lytic polysaccharide monooxygenase (LPMO) SbAA14 from Sordaria brevicollis was successfully characterized. It was active against heteroxylan, xyloglucan and cellulose in β-cellulose and released native oligosaccharides and corresponding C1- and/or C4-oxidized products. SbAA14 showed a branched chain preference, because partial removal of arabinosyl substituents from heteroxylan led to a decrease in activity. SbAA14 had synergistic effects with the debranching enzyme EpABF62C in an enzyme- and ascorbic acid-dependent manner. SbAA14 had synergistic effects with the GH10 endoxylanase EpXYN1, and the degree of synergy was greater with step-by-step addition than with simultaneous addition. SbAA14 could also synergize with Celluclast® 1.5 L on NaOH-pretreated wheat straw and on NaOH-pretreated and hydrogen peroxide-acetic acid (HPAC)-H2SO4-pretreated bamboo substrates. The greatest synergistic effect between SbAA14 and Celluclast® 1.5 L was observed for HPAC-H2SO4-200 mM pretreated bamboo, in which the degree of synergy reached approximately 1.61. The distinctive substrate preference of SbAA14 indicated that it is a novel AA14 LPMO that may act mainly on heteroxylan with numerous arabinosyl substituents between cellulose fibers rather than on recalcitrant xylan tightly associated with cellulose. These findings broaden the understanding of enigmatic AA14 LPMOs and provide new insights into the substrate specificities and biological functionalities of AA14 LPMOs in fungi.

A novel AA14 LPMO from Talaromyces rugulosus with bifunctional cellulolytic/hemicellulolytic activity boosted cellulose hydrolysis

BACKGROUND

The recently discovered PcAA14A and B from white-rot basidiomycete Pycnoporus coccineus enriched our understanding of the oxidative degradation of xylan in fungi, however, the unusual mode of action of AA14 LPMOs has sparked controversy. The substrate specificity and functionality of AA14 LPMOs still remain enigmatic and need further investigation.

RESULTS

In this study, a novel AA14 LPMO was characterized from the ascomycete Talaromyces rugulosus. TrAA14A has a broad substrate specificity with strong oxidative activity on pure amorphous cellulose and xyloglucan. It could simultaneously oxidize cellulose, xylan and xyloglucan in natural hemi/cellulosic substrate such as fibrillated eucalyptus pulp, and released native and oxidized cello-oligosaccharides, xylo-oligosaccharides and xyloglucan oligosaccharides from this substrate, but its cellulolytic/hemicellulolytic activity became weaker as the contents of xylan increase in the alkaline-extracted hemi/cellulosic substrates. The dual cellulolytic/hemicellulolytic activity enables TrAA14A to possess a profound boosting effect on cellulose hydrolysis by cellulolytic enzymes. Structure modelling of TrAA14A revealed that it exhibits a relatively flat active-site surface similar to the active-site surfaces in AA9 LPMOs but quite distinct from PcAA14B, despite TrAA14A is strongly clustered together with AA14 LPMOs. Remarkable difference in electrostatic potentials of L2 and L3 surfaces was also observed among TrAA14A, PcAA14B and NcLPMO9F. We speculated that the unique feature in substrate-binding surface might contribute to the cellulolytic/hemicellulolytic activity of TrAA14A.

CONCLUSIONS

The extensive cellulolytic/hemicellulolytic activity on natural hemi/cellulosic substrate indicated that TrAA14A from ascomycete is distinctively different from previously characterized xylan-active AA9 or AA14 LPMOs. It may play as a bifunctional enzyme to decompose some specific network structures formed between cellulose and hemicellulose in the plant cell walls. Our findings shed new insights into the novel substrate specificities and biological functionalities of AA14 LPMOs, and will contribute to developing novel bifunctional LPMOs as the booster in commercial cellulase cocktails to efficiently break down the hemicellulose-cellulose matrix in lignocellulose.

Microbial α-L-arabinofuranosidases: diversity, properties, and biotechnological applications

Arabinoxylans (AXs) are hemicellulosic polysaccharides consisting of a linear backbone of β-1,4-linked xylose residues branched by high content of α-L-arabinofuranosyl (Araf) residues along with other side-chain substituents, and are abundantly found in various agricultural crops especially cereals. The efficient bioconversion of AXs into monosaccharides, oligosaccharides and/or other chemicals depends on the synergism of main-chain enzymes and de-branching enzymes. Exo-α-L-arabinofuranosidases (ABFs) catalyze the hydrolysis of terminal non-reducing α-1,2-, α-1,3- or α-1,5- linked α-L-Araf residues from arabinose-substituted polysaccharides or oligosaccharides. ABFs are critically de-branching enzymes in bioconversion of agricultural biomass, and have received special attention due to their application potentials in biotechnological industries. In recent years, the researches on microbial ABFs have developed quickly in the aspects of the gene mining, properties of novel members, catalytic mechanisms, methodologies, and application technologies. In this review, we systematically summarize the latest advances in microbial ABFs, and discuss the future perspectives of the enzyme research.

[Study on primary screening technique for children with autism spectrum disorder]

To explore screening tools for children with autism spectrum disorder (ASD), which are convenient for primary hospitals, it can provide basic data for formulating ASD prevention policies. This was a cross-sectional study by cluster sampling. Huyi District and Xincheng District were extracted for investigation in Xi'an City. From July 2021 to September 2022, all children aged from 3 months to 36 months who live in the two districts were subjected to primary screening. The child care physician used the routine screening tool "warning signs checklist for screening psychological, behavioral and developmental problems of children" and cartoon pictures of "early high-risk warning signs of autism", the children who were positive in the initial screening were referred to the district level maternal and child health hospital for re-screening, and those who were positive in the re-screening were referred to Xi 'an Children's Hospital for diagnosis. The results showed that a total of 17 905 children aged from 3 months to 36 months were initially screened in the two districts, including 10 588 children aged from 18 months to 36 months, 50 children who were positive in the initial screening and 50 children who were re-screened. 23 children (18 boys and 5 girls) were diagnosed with ASD. The prevalence rate of ASD in children was 2.17‰ (95% confidence interval:1.29‰-3.06‰). 42 children were positive for "warning signs checklist" at the preliminary screening, and 19 were confirmed as ASD. 27 children were positive for "cartoon pictures" in the preliminary screening, and 23 were confirmed with ASD. The "cartoon pictures" in the preliminary screening and diagnosis of consistent rate was higher than the "warning signs checklist", two kinds of screening methods comparison were statistically significant difference in the odds of consistent (χ2=11.01, P=0.001). In conclusion, relying on the three-level network of maternal and child health care, it is conducive to the whole process management of screening and diagnosis of children with ASD, and to guide the formulation of prevention policies. The cartoon pictures of "early high-risk warning signs of autism" can assist the identification of children with ASD based on the "warning signs checklist", which is simple, effective and suitable for promotion in the community health care.

Identification and adaptive evolution analysis of glutaredoxin genes in Populus spp

Glutaredoxin (GRX) is a class of small redox proteins widely involved in cellular redox homeostasis and the regulation of various cellular processes. The role of GRX gene in the differentiation of Populus spp. is rarely reported. We compared the similarities and differences of GRX genes among four sections of poplar using bioinformatics, corrected the annotations of some GRX genes, and focused on analysing their transcript profiling and adaptive evolution in Populus spp. A total of 219 GRX genes were identified in four sections of poplar, among which annotations for 13 genes were corrected. Differences in GRX genes were found between sect. Turanga, represented by P. euphratica, and other poplar sections. Most notably, P. euphratica had the smallest number of duplication events for GRX genes (n = 9) and no tandem duplications, whereas there were >25 duplication events for all other poplars. Furthermore, we detected 18 pairs of GRX genes under positive selection pressure in various sections of poplar, and identified two groups of GRX genes in the Salicaceae that potentially underwent positive selection. Expression profiling results showed that the PtrGRX34 and its orthologous genes were upregulated under stress treatments. In summary, the GRX gene family underwent expansion during poplar differentiation, and some genes underwent rapid evolution during this process, which may be beneficial for Populus spp. to adapt to environmental changes. This study may provide more insights into the molecular mechanisms of Populus spp. adaptation to environmental changes and the adaptive evolution of GRX genes.

High-level production of cordycepin by the xylose-utilising Cordyceps militaris strain 147 in an optimised medium

Cordycepin is an important active metabolite of Cordyceps militaris. Xylose, an attractive feedstock for producing chemicals through microbial fermentation, cannot be effectively utilised by many reported C. militaris strains. Herein, a xylose-utilising C. militaris strain 147 produced the highest level of cordycepin (3.03 g/L) in xylose culture. Xylose, alanine, and ammonium citrate were determined as the main affecting factors on the cordycepin production using a Plackett-Burman design. The combination of these factors was optimised using response surface methodology, and the maximal 6.54 g/L of cordycepin was produced by the fungus in the optimal medium. Transcriptome analysis revealed that xylose utilisation upregulated the transcriptional levels of genes participating in purine and energy metabolisms in the fungus, which may facilitate the formation of precursors for cordycepin biosynthesis. This investigation provides new insights into the efficient production of cordycepin and is conducive to the valorisation of biomass rich in xylose.

Potential Predictive Value of Intravoxel Incoherent Motion Magnetic Resonance for Xerostomia of Nasopharyngeal Carcinoma

PURPOSE/OBJECTIVE(S)

Xerostomia, caused by radiation-induced parotid damage, is the most commonly reported complications of radiotherapy (RT) to nasopharyngeal carcinoma (NPC). This study aimed to evaluate the value of IVIM MR in monitoring radiation parotid gland damage and predicting the risk of xerostomia.

MATERIALS/METHODS

A total of 54 patients were enrolled and underwent IVIM MR scans at before RT, after the fifth fraction, halfway through the course of RT, and at the end of radiotherapy. The parameters of IVIM MR include pseudo-diffusion coefficient (D*), perfusion fraction (f), and pure diffusion coefficient (D). The degree of xerostomia in NPC patients was assessed before each MR examination using the acute radiation morbidity scoring criteria proposed by the Radiation Therapy Oncology Group (RTOG). Concurrently, the time when the patient first reported suffering from xerostomia was recorded. The IVIM parameters trend throughout the RT, and the relationships between IVIM parameters and xerostomia, were analyzed.

RESULTS

All of the IVIM parameters increased from pre-RT to post-RT significantly (all p < 0.001). The increase rate of D from pre-RT to halfway through the RT was 32.61%, which was significantly higher than 15.64% from halfway to post-RT (p<0.001), indicating that cell necrosis in the first half of treatment is significantly higher than that in the second half. Both D* and F had significantly increased from pre-RT to halfway through the radiotherapy (p<0.001), with an increase rate of 19.58% and 29.38%, respectively. However, no significant increase was observed from Halfway to post-RT (p>0.05), with an increase rate of 4.10% and 8.30%, respectively. This may be due to radiation-induced vasculitic dilation that is significant in the first half of the radiotherapy but plateaus in the second half. Pre-D (OR = 23.85; 95% CI = 2.39, 237.82; p = .007) and pre-D* (OR = 0.75; 95% CI = 0.63, 0.91; p = 0.003) are independent influencing factors for xerostomia at 3 months after the completion of RT. D and F were significantly higher after the fifth fraction compared with Pre-RT (both p<0.05), respectively increased 31.25% and 25.16%. D* increase by 15% (p = 0.081). IVIM scans can assess parotid gland damage early. And the average time of parotid damage underwent IVIM scan was 5.99 ± 0.84 (day), much earlier than 11.84 ± 2.74 (day) according to RTOG.

CONCLUSION

Our study indicates that IVIM MR can dynamically monitor radiotherapy-induced parotid gland damage, and much earlier and objectively than RTOG.

Insights into the capability of the lignocellulolytic enzymes of Penicillium parvum 4-14 to saccharify corn bran after alkaline hydrogen peroxide pretreatment

BACKGROUND

Corn bran is a major agro-industrial byproduct from corn starch processing. It contains abundant arabinoxylan that can be converted into value-added chemicals via biotechnology. Corn bran arabinoxylan (CBAX) is one of the most recalcitrant xylans for enzymatic degradation due to its particular heterogeneous nature. The present study aimed to investigate the capability of the filamentous fungus Penicillium parvum 4-14 to enzymatically saccharify CBAX and reveal the fungal carbohydrate-active enzyme (CAZyme) repertoire by genome sequencing and secretome analysis.

RESULTS

CBAX1 and CBAX2 with different branching degrees, together with corn bran residue (CBR) were generated from corn bran after alkaline hydrogen peroxide (AHP) pretreatment and graded ethanol precipitation. The protein blends E_CBAX1, E_CBAX2, and E_CBR were produced by the fungus grown on CBAX1, CBAX2, or CBR, respectively. Under the optimal conditions, E_CBAX1 released more than 80% xylose and arabinose from CBAX1 and CBAX2. Almost complete saccharification of the arabinoxylans was achieved by combining E_CBAX1 and a commercial enzyme cocktail Cellic®CTec3. Approximately 89% glucose, 64% xylose, and 64% arabinose were liberated from CBR by E_CBR. The combination of E_CBR with Cellic®CTec3 enhanced the saccharification of CBR, with conversion ratios of 97% for glucose, 81% for xylose, and 76% for arabinose. A total of 376 CAZymes including plentiful lignocellulolytic enzymes were predicted in P. parvum based on the fungal genomic sequence (25.8 Mb). Proteomic analysis indicated that the expression of CAZymes in P. parvum varied between CBAX1 and CBR, and the fungus produced complete cellulases, numerous hemicellulases, as well as high levels of glycosidases under the culture conditions.

CONCLUSIONS

This investigation disclosed the CAZyme repertoire of P. parvum at the genomic and proteomic levels, and elaborated on the promising potential of fungal lignocellulolytic enzymes upon saccharification of corn bran biomass after AHP pretreatment.

Evaluation of the Efficiency of TIMP-2 as a Biomarker for Acute Kidney Injury in Sepsis

The aim of this study was to evaluate the biomarker potential of TIMP-2 in septic-induced acute kidney injury (AKI). Healthy male rats (n=56, age 8-10 weeks, body weight 250-300 g) were randomized into 3 groups: controls (intact rats, n=6), sham-operated (SO, n=24), and sepsis model (cecum ligation and perforation, CLP, n=24). Thirty minutes before and 6, 12, 24, and 48 h after surgery, blood samples were collected to measure serum creatinine, blood urea nitrogen (BUN), and TIMP-2 and the kidneys were isolated for histopathological analysis and Western blotting. The key sepsis-related genes were screened through bioinformatics analysis. In 24 and 48 h after surgery, 2 rats in the SO group reached the diagnostic criteria of AKI (increased levels of serum creatinine and BUN). In the CLP group, serum creatinine in 6 h after the surgery was slightly higher than 30 min before the surgery, but this change did not meet the diagnostic criteria for AKI. In the CLP group, BUN was normal 6 h after the surgery, but increased after 12 h. In more than 50% rats of the CLP group, serum creatinine and BUN significantly increased 12 h after operation, so this can be diagnosed as AKI. In rats of the CLP group, plasma TIMP-2 was elevated 6 h after surgery and increased with time, suggesting that plasma TIMP-2 can be used as an early marker of AKI. Histological examination of the kidneys in this group revealed destruction of the renal tubular structure, swelling of renal tubular epithelium, the disappearance of brush edge and collapse of necrotic epithelial cells, etc., and the degree of damage increased with time. Immunohistochemistry showed that TIMP-2 was expressed in rats of the CLP group at all terms of the experiment. The expression of TIMP-2 and pyroptosis-related proteins (NLRP3, IL-1β, caspase-1, and GSDMD) in the CLP group was higher than in the SO group (p<0.05) and increased with time, suggesting that pyroptosis is involved in AKI. Thus, plasma TIMP-2 is sensitive indicator for the early detection of kidney injury and can be used as an early biomarker of AKI.

Analysis of clinical features, treatment, and prognosis of primary Xlymphoepithelioma-like carcinoma of the lung

OBJECTIVE

Primary pulmonary lymphoepithelioma-like carcinoma (PPLELC) is a rare lung malignancy occurring most frequently in young non-smokers from Southeast Asia. Given its low incidence, PPLELC clinical features, treatment methods, and the factors affecting its prognosis remain elusive. To date, PPLELC data are mainly derived from clinical case reports, and no cohort studies are available. Therefore, we retrospectively analyzed a group of PPLELC cases and summarized the clinical features of patients, treatment responses, and the factors affecting patient prognosis.

PATIENTS AND METHODS

A total of 91 patients having primary pulmonary lymphoepithelioma-like carcinoma were recruited in this study. These included sex, age, place of birth, smoking history, pre-treatment symptoms, tumor location, tumor markers, maximum tumor diameter, treatment regimen, lymph node presence metastasis after an operation, pathological picture, immunohistochemistry, genetic findings, and tumor stage grading. We determined the overall survival (OS), progression-free survival (PFS), basic clinical characteristics, treatment option, treatment response, and recurrence pattern among the patients. In addition, we understood the influence of sex, age, tumor, nodes, and metastases (TNM) stage, tumor size, and surgery over patient prognosis.

RESULTS

Primary pulmonary lymphoepithelioma-like carcinoma is more common among young non-smokers, with a slightly higher incidence in women than in men. The expression of Epstein-Barr virus-encoded small RNA (EBER), pancytokeratin (PCK), Cytokeratin 5/6 (CK5/6), and tumor protein 63 (P63) was positive in immunohistochemistry. Serum cytokeratin 19 fragment antigen (CYFRA21-1) and Epstein-Barr DNA (EB-DNA) could be used as markers to diagnose primary pulmonary lymphoepithelioma-like carcinoma. TNM stage and surgery were independent prognostic factors.

CONCLUSIONS

Primary pulmonary lymphoepithelioma-like carcinoma is rare, showing a good prognosis.

AB0206 STUDY ON THE SIGNIFICANCE OF SERUM COMPLEMENT C5 IN PATIENTS WITH RHEUMATOID ARTHRITIS

Background

Recent studies have pointed out that complement system activation is a major alteration in early atherosclerotic plaques, and complement C5 has promising value as a novel circulating biomarker of atherosclerosis, but the relationship between C5 and carotid atherosclerotic (CAS) plaque in rheumatoid arthritis (RA) is still unclear.

Objectives

To investigate the clinical significance of serum complement C5 and the association with CAS plaque in patients with RA．

Methods

143 patients with RA were included in the study, and 46 cases with age- and sex- matched healthy physical examination without RA or CAS plaque served as a normal control. All RA patients were divided into RA with CAS plaque group and RA without CAS plaque group according to the presence or absence of plaque formation in the carotid artery. The subject’s demographic data, laboratory investigations and serum samples were collected. Body mass index (BMI) and Disease Activity Score 28-joint counts (DAS28) were calculated. Glucocorticoid and DMARDS use were recorded in the past 3 months. ELISA method was used to determine the concentration of complement C5 in the serum of each participation. CAS plaque was determined by color Doppler ultrasound.

Results

Serum complement C5 in RA group was significantly lower than that in control group (P<0.05), whereas C5 level in RA with CAS plaque group was significantly higher than that in RA without CAS plaque group (P<0.05). In RA group, serum C5 level was positively correlated with CAS plaque, high-sensitivity C-reactive protein (hs-CRP) and fibrinogen (FIB) (r=0.204, P=0.017; r=0.225, P=0.009; r=0.186, P=0.029;). In addition, there was no significant correlation between serum C5 and sex, age, BMI, course of disease, DAS28, lipid profile (TG, serum triglyceride; TC, total cholesterol; LDLC, low density lipoprotein cholesterol; HDLC, high density lipoprotein cholesterol; TC/HDLC; LDLC/HDLC), immune markers (RF, rheumatoid factor; anti-CCP, anti-cyclic citrullinated peptide antibodies), cytokine (IL-6, Interleukin-6; TNF-α, Tumor necrosis factor-α), erythrocyte sedimentation rate (ESR) (all P>0.05), or drug therapy (all P>0.05).

Conclusion

C5 may be a novel circulating marker of atherosclerosis in RA patients, it might promise to assist in risk stratification for cardiovascular disease in the future.

References

[1]Martínez-López D, et al. Complement C5 Protein as a Marker of Subclinical Atherosclerosis. J Am Coll Cardiol. 2020 Apr 28;75(16):1926-1941.

Disclosure of Interests

None declared

AB1279 POOR QUALITY OF LIFE AND REDUCED WORK PRODUCTIVITY IN EUROPEAN PATIENTS WITH DERMATOMYOSITIS AND POLYMYOSITIS: FINDINGS FROM A SYSTEMATIC LITERATURE REVIEW

Background

Dermatomyositis (DM) and polymyositis (PM) are rare heterogenous systemic autoimmune disorders of the skin, muscles, and other organs with few effective treatment options available. They are described as devastating diseases but the full impact on patients’ lives in Europe is not well understood.

Objectives

To systematically review and summarize evidence on humanistic burden of disease in patients with DM and PM in Europe to better understand patient-relevant aspects of disease and key domains of life impacted by DM and PM in the European setting.

Methods

A systematic literature review (SLR) was conducted in MEDLINE and Embase databases to identify studies in children and adults with DM and PM, published in the English language between Jan 1, 2011, and Apr 28, 2021. Only primary studies enrolling 10 or more patients were included, irrespective of country or region. Each eligible article was independently reviewed by two reviewers. The title and study abstracts were reviewed to assess eligibility for full-text review. The topics of interest were clinical, humanistic, and economic burden of disease, as well as current management and unmet needs in DM and PM. Information on geographic scope was extracted from the papers of included studies. The current abstract summarizes SLR results on humanistic burden of DM and PM in European patients.

Results

A total of 2,967 non-duplicated publications were retrieved from medical databases and analyzed against pre-defined study selection criteria. There were 2,574 records excluded at title and abstract screening. Remaining 393 records were analyzed in the full text with 208 papers considered relevant. Additional 21 papers were identified from searching reference list of relevant studies and conference proceedings. In total, 222 studies described in 229 publications were included in data abstraction. Among 43 studies conducted across 14 European countries, 12 studies evaluated health-related quality of life (HRQoL) and work productivity in patients with DM and PM. In 6 studies, patients received standard of care therapy. Six studies enrolled adults with DM and PM and 6 were conducted in patients with juvenile onset of DM. There were 6 cross-sectional analyses, 4 longitudinal cohort studies, 2 case-control studies, with sample size ranging from 11 to 246 patients. Adults with DM and PM had significantly worse HRQoL across multiple domains of 36-Item Short Form Survey (SF-36) compared to controls from general population, with a strong negative impact of muscle weakness on physical functioning. Patients reported high difficulties in performing leisure time activities, moving around and work as indicated by median scores of 4-5 points in a 7-point Myositis Activity Profile (MAP). Reduced grip force in DM and PM adults was significantly associated with worse performance in domestic activities in the MAP assessment (p<0.05). In women with DM and PM, poor grip force additionally impacted vitality and mental health as measured by SF-36 (p<0.05). There were no associations between grip force and any SF-36 domain in men. Approximately 60% of adult patients rated their ability to work as “poor” or “less good” according to the Work Ability Index, 68% of patients had more than one week of sick leave in the past year, and 20.8% of them were permanently not able to work for at least 2 years. Children and adolescents with DM had impaired physical and psychosocial functioning compared to healthy norms with 40% of individuals showing increased emotional distress requiring in-depth psychological assessment.

Conclusion

European patients with DM and PM experience a muscle weakness that has a detrimental impact on HRQoL, daily activities and ability to work. Similar disease impact on HRQoL was reported in patients in North America. These findings suggest a need for a novel therapy that will restore physical functioning in patients with DM and PM.

Disclosure of Interests

Jens Schmidt Speakers bureau: Euroimmun, CSL Behring, Consultant of: Alnylam, Argenx, Biotest, CSL Behring, Kezar Life Sciences, LFB, Novartis, Octapharma, UCB, Grant/research support from: CSL Behring, Novartis, Konrad Pisarczyk Consultant of: Kezar Life Sciences, Richard Leff Shareholder of: Kezar Life Sciences, Consultant of: Kezar Life Sciences, Kiruthi Palaniswamy Shareholder of: Kezar Life Sciences, Employee of: Kezar Life Sciences, Eunmi Park Shareholder of: Kezar Life Sciences, Employee of: Kezar Life Sciences, Li Long Shareholder of: Kezar Life Sciences, Employee of: Kezar Life Sciences

AB1277 POOR LONG-TERM OUTCOMES AND SUBSTANTIAL BURDEN OF COMORBIDITIES IN EUROPEAN PATIENTS WITH DERMATOMYOSITIS/POLYMYOSITIS: RESULTS FROM A SYSTEMATIC LITERATURE REVIEW

Background

Dermatomyositis (DM) and polymyositis (PM) are rare heterogenous systemic autoimmune disorders of the skin, muscles and other organs that may have a devastating impact on patients’ lives. Despite various therapies used in clinical practice, a notable proportion of patients seem not to achieve sustainable remission. There is a need to better understand long-term outcomes and comorbidities in patients with DM/PM in Europe.

Objectives

To systematically review and summarize evidence on clinical burden of disease in patients with DM/PM in Europe.

Methods

A systematic literature review (SLR) was conducted in MEDLINE and Embase databases to identify studies in children and adults with DM/PM, published in the English language between 2011 and 2021. Primary studies enrolling 10 or more patients were included, irrespective of country or region. Each eligible article was independently reviewed by two reviewers. The title and study abstracts were reviewed to assess eligibility for full-text review. The current abstract summarizes SLR results on the long-term outcomes and comorbidities in patients with DM/PM in Europe.

Results

A total of 2,967 non-duplicated publications were retrieved from medical databases and analyzed against pre-defined study selection criteria. There were 2,574 records excluded at title and abstract screening. Remaining 393 records were analyzed in the full text with 208 papers considered relevant. Additional 21 papers were identified from searching reference list of relevant studies and conference proceedings. In total, 222 studies (229 publications) were included in data abstraction. Among 43 studies conducted across 14 European countries, 23 studies evaluated long-term outcomes of disease and burden of comorbidities. There were 14 longitudinal cohort studies, 7 cross-sectional analyses and 2 case-control studies. Only 29-44% of DM/PM adults achieved remission. Between 38% and 62% of adults with DM/PM required at least 3 different medications, suggesting inadequate response to initial and subsequent regimens. During a mean follow-up of 13.9 years, 69% patients with JDM had polycyclic or chronic disease characterized by periods of remission and recurrence or by permanently active disease for more than 2 years after diagnosis. A notable proportion of children (60.4%) showed evidence of damage in at least one body organ and 13-20% of patients had complications such as calcinosis, lipodystrophy, or muscle atrophy. Adults with DM/PM often suffered from interstitial lung disease (16-66%), serious infections leading to hospitalization or death (21-26.7%), and cardiovascular disorders (CVDs) (19-71%). Compared to age and gender matched controls without DM, patients with DM had 16-times higher risk of venous thromboembolism (HR=16.44, 95% CI: 7.54-35.86). Incidence of coronary heart disease, hemorrhagic stroke, or ischemic stroke during 10-year follow-up was approximately 1.5- to 2-times higher in DM/PM adults relative to general population. Multiple studies reported high rates of any malignancy in DM adults (7.5-33%) and in PM adults (8-11.7%). During approximately 24,000 patient-years of follow-up, adults with DM/PM had more than 4-times higher incidence of lung cancer compared to general population that also was one of the highest incidences among multiple other autoimmune diseases. Long-term prognosis in DM/PM was poor with 20-year survival below 70%. The most common causes of deaths were pulmonary-related, malignancies, and cardiac complications. Mortality due to lung cancer was more than 4-times higher than in general population (standardized mortality ratio=4.17, 95% CI: 3.03-5.60).

Conclusion

European patients with DM/PM suffer from substantial burden of comorbidities including serious infections, malignancies and CVDs that lead to poor long-term outcomes. A notable proportion of adult and juvenile patients do not achieve sustainable remission or experience relapse indicating high unmet need.

Disclosure of Interests

Jiří Vencovský Speakers bureau: Abbvie, Biogen, Boehringer, Eli Lilly, Gilead, MSD, Novartis, Pfizer, Roche, Sanofi, UCB, Werfen, Consultant of: Abbvie, Argenx, Boehringer, Eli Lilly, Gilead, Octapharma, Pfizer, UCB, Grant/research support from: Abbvie, Konrad Pisarczyk Consultant of: Kezar Life Sciences, Richard Leff Shareholder of: Kezar Life Sciences, Consultant of: Kezar Life Sciences, Eunmi Park Shareholder of: Kezar Life Sciences, Employee of: Kezar Life Sciences, Kiruthi Palaniswamy Shareholder of: Kezar Life Sciences, Employee of: Kezar Life Sciences, Li Long Shareholder of: Kezar Life Sciences, Employee of: Kezar Life Sciences.

Functional characterization of a new 3-dehydroshikimate dehydratase from Eupenicillium parvum and its potential for protocatechuic acid production

Protocatechuic acid (PCA) is an important phenolic compound with diverse industrial values. Conversion of 3-dehydroshikimate (DHS) to PCA by dehydroshikimate dehydratase (DSD) provides an efficient approach for production of the molecule. Herein, a new DSD from fungus Eupenicillium parvum was functionally investigated after recombinant expression in Escherichia coli. The DSD displayed 30-35% sequence identities with the known fungal DSDs. The recombinant protein showed catalysis activity against DHS, with the optimal temperature of 40°C and pH of 7.5. The specific activity and Km of the protein were 910 mU per mg protein and 0.83 mM, respectively. Metal ion (Mg2+ or Mn2+) played a critical role for the enzymatic activity. Meanwhile, the thermal stability of the protein was improved by Mg2+ or Mn2+. Furthermore, the expression of the protein in E. coli resulted in de novo synthesis of 491 mg/L PCA in a modified M9 medium with glycerol as carbon source.

[Observation of PD-1+CXCR5+CD4+T lymphocyte and sPD-1 levels in HBeAg positive chronic hepatitis B virus carriers treated with entecavir]

Objective: To dynamically observe the clinical efficacy of entecavir and the changes of PD-1⁺CXCR5⁺CD4⁺T lymphocytes and sPD-1 levels in peripheral blood of HBeAg-positive chronic hepatitis B virus carriers treated with entecavir, and further explore its clinical significance. Methods: There were 31 cases of chronic hepatitis B virus carriers in the treatment group (A), 32 cases of chronic hepatitis B virus carriers in the treatment group (B), and 15 cases of chronic hepatitis B virus carriers in the non-treatment group (C).Three groups peripheral blood samples and clinical data at 0, 24 and 48 weeks were collected and compared. PD-1⁺CXCR5⁺CD4⁺T lymphocytes were detected by flow cytometry, and the level of sPD-1 was detected by enzyme-linked immunosorbent assay. ANOVA and Spearman correlation analysis were performed on the measurement data among the three groups. Results: At week 0, the serum levels of HBsAg, HBeAg and HBV DNA were significantly higher in groups A and C than group B. PD-1⁺CXCR5⁺CD4⁺T lymphocytes in peripheral blood were significantly higher in group B (4.70%±1.58%) than group A (3.25%±1.01%) and group C (2.77%±0.67%) (F=16.65, P<0.05). There was no significant difference between group A and group C (P>0.05). Peripheral blood sPD-1 in group B [(1 866.62±1 472.70) pg/ml] was significantly higher than group A [(824.86±538.66) pg/ml] and group C [(618.19±602.62) pg/ml] (F=10.95, P<0.05). There was no significant difference between group A and group C (P>0.05). At 48 weeks, the serum HBsAg did not decrease significantly in groups A and C than baseline (P>0.05), but were significantly higher than group B (P<0.05). Serum HBeAg levels were decreased significantly in groups A and B than baseline (P<0.05). <0.05), but group A was significantly higher than group B (P<0.05), and there was no significant difference between group A and group C (P>0.05). Serum HBV DNA level was significantly lower in groups A and B than group C (P<0.05), and there was no significant difference between group A and group B (P>0.05). Peripheral blood PD-1⁺CXCR5⁺CD4⁺T lymphocytes were significantly lower in Group A (1.56%±0.73%) and group B (1.32%±0.43%) than group C (2.64%±0.85%) (P<0.05). Peripheral blood sPD-1 were significantly lower in group A [(289.05±215.86) pg/ml] and group B [(236.01±173.92) pg/ml] than group C [(650.34±598.46) pg/ml] (P<0.05). There was no significant difference between group A and group B. Correlation analysis results: In group A at 48 weeks, the decreased level of PD-1⁺CXCR5⁺CD4⁺T lymphocyte ratio had no correlation with the decreased level of HBsAg and HBV DNA, but was positively correlated with the decreased level of HBeAg (r=0.376, P<0.05). The decreased level of sPD-1 had no correlation with the changes of HBsAg, but was positively correlated with the decreased levels of HBeAg and HBV DNA (r=0.598 and 0.384, P<0.05). In group B at 48 weeks, the decreased levels of PD-1⁺CXCR5⁺CD4⁺T lymphocytes and sPD-1 were positively correlated with the decreased levels of HBsAg, HBeAg, and HBV DNA (P<0.05). Conclusion: Hepatitis B virus replication and expressions in HBeAg-positive chronic hepatitis B virus carriers were significantly inhibited after 48 weeks of antiviral treatment, which is related not only to entecavir treatment, but also to the immunological mechanism involved in sPD-1. Moreover, the inhibition of HBeAg expression is associated with a decrease in the number and/or activity of PD-1⁺CXCR5⁺CD4⁺T lymphocytes.

Genomic sequence and transcriptome analysis of the medicinal fungus Keithomyces neogunnii

The filamentous fungus Keithomyces neogunnii can infect the larvae of Lepidoptera (Hepialus sp.) and form an insect–fungi complex, which is utilized as an important traditional Chinese medicine. As a valuable medicinal fungus, K. neogunnii produces diverse bioactive substances (e.g., polysaccharide, vitamins, cordycepic acid, and adenosine) under cultivation conditions. Herein, we report the first high-quality genome of the K. neogunnii single-spore isolate Cg7.2a using single-molecule real-time sequencing technology in combination with Illumina sequencing. The assembled genome was 32.6 Mb in size, containing 8,641 predicted genes and having a GC content of 52.16%. RNA sequencing analysis revealed the maximum number of differentially expressed genes in the fungus during the stroma formation stage compared with those during the mycelium stage. These data are valuable to enhance our understanding of the biology, development, evolution, and physiological metabolism of K. neogunnii.

Functional characterization of a GH62 family α-L-arabinofuranosidase from Eupenicillium parvum suitable for monosaccharification of corncob arabinoxylan in combination with key enzymes

Corncob rich in arabinoxylan is an important raw material widely used in bio-refinery. Complete saccharification of arabinoxylan depends on the synergism of different enzymes including α-L-arabinofuranosidase (ABF). This study aimed to investigate the functional characteristics of a new ABF EpABF62A belonging to glycoside hydrolase (GH) 62 family from the fungus Eupenicillium parvum, and to explore its potential in the saccharification of corncob arabinoxylan. The recombinant EpABF62A showed high activity against wheat arabinoxylan and rye arabinoxylan, with the optimal temperature of 55 °C and pH of 4.5. The protein contains an N-terminal cellulose-binding domain family 1 (CBM_1) domain, and displayed a 59.5% absorption rate to phosphoric acid swollen cellulose. Regioselectivity analysis indicated that the enzyme selectively removed α-1,2 or α-1,3 linked arabinofuranosyl residues on mono-substituted xylose residues on arabinoxylan. Corncob arabinoxylans (CAX1 or CAX2) with different (low or high) branching degrees were extracted from the raw material by alkaline hydrogen peroxide pretreatment and graded ethanol precipitation. Single EpABF62A removed 69.5% or 67.1% arabinose from CAX1 or CAX2, respectively. EpABF62A combined with a GH10 xylanase, a GH43 β-D-xylosidase and a GH67 α-glucuronidase released 75.0% or 64.5% xylose from CAX1 or CAX2, respectively. The addition of the four hemicellulases enhanced the saccharification the solid fraction of the pretreated corncob by the commercial cellulase Cellic® CTec2, and the conversion ratios of glucose, xylose and arabinose were up to 94.0%, 91.8% and 82.6%, respectively.

Two C1-oxidizing AA9 lytic polysaccharide monooxygenases from Sordaria brevicollis differ in thermostability, activity, and synergy with cellulase

Cellulolytic fungi usually have multiple genes for C1-oxidizing auxiliary activity 9 (AA9) lytic polysaccharide monooxygenases (LPMOs) in their genomes, but their potential functional differences are less understood. In this study, two C1-oxidizing AA9 LPMOs, SbLPMO9A and SbLPMO9B, were identified from Sordaria brevicollis, and their differences, particularly in terms of thermostability, reducing agent specificity, and synergy with cellulase, were explored. The two enzymes exhibited weak binding to cellulose and intolerance to hydrogen peroxide. Their oxidative activity was influenced by cellulose crystallinity and surface morphology, and both enzymes tended to oxidize celluloses of lower crystallinity and high surface area. Comparably, SbLPMO9A had much better thermostability than SbLPMO9B, which may be attributed to the presence of a carbohydrate binding module 1 (CBM1)-like sequence at its C-terminus. In addition, the two enzymes exhibited different specificities and responsivities toward electron donors. SbLPMO9A and SbLPMO9B were able to boost the catalytic efficiency of endoglucanase I (EGI) on physically and chemically pretreated substrates but with different degrees of synergy. Substrate- and enzyme-specific synergism was observed by comparing the synergistic action of SbLPMO9A or SbLPMO9B with commercial Celluclast 1.5L on three kinds of cellulosic substrates. On regenerated amorphous cellulose and PFI (Papirindustriens Forskningsinstitut)-fibrillated bleached eucalyptus pulp, SbLPMO9B showed a higher synergistic effect than SbLPMO9A, while on delignified wheat straw, the synergistic effect of SbLPMO9A was higher than that of SbLPMO9B. On account of its excellent thermostability and boosting effect on the enzymatic hydrolysis of delignified wheat straw, SbLPMO9A may have high application potential in biorefineries for lignocellulosic biomass. KEY POINTS: • C1-oxidizing SbLPMO9A displayed higher thermostability than SbLPMO9B, probably due to the presence of a CBM1-like module. • The oxidative activity of the two SbLPMO9s on celluloses increased with decreasing cellulose crystallinity or increasing beating degree. • The two SbLPMO9s boosted the catalytic efficiency of cellulase, but the synergistic effect was substrate- and enzyme-specific.

1521 Oral Foregut Duplication Cyst in A Neonate: A Case Report and Review of The Literature

A four-day-old neonate was referred to the Oral and Maxillofacial Surgery department by the Paediatric medical team regarding a cystic lesion associated with the child’s lingual frenulum. The lesion appeared to be affecting feeding causing a potential failure to thrive.

An MRI showed a 22 x 14 x 17 mm thin-walled oval cystic structure within the midline of the tongue/floor of the mouth. The decision was made with the family to surgically excise the lesion under a general anaesthetic. The histopathology results demonstrated the cyst to be lined with both gastric surface mucus cells and ciliated respiratory-type epithelium.

The patient was diagnosed with having an Oral Foregut Duplication Cyst (OFDC), also known as a lingual choristoma, enteric duplication cyst or heterotopic gastrointestinal cyst of the oral cavity. OFDCs are benign developmental anomalies that contain foregut derivatives. The cyst linings can contain gastrointestinal, respiratory, squamous or mixed cell types. There are only approximately 58 cases reported in the literature, demonstrating the rarity of these lesions.

OFDCs can be asymptomatic but in some neonates, they can present with difficulties feeding, swallowing and even has been shown to cause airway obstruction. If left in situ an OFDC can potentially go on to hinder speech development.

Although rare, OFDCs should be considered in a differential diagnosis of congenital oral lesions and in particular those of the anterior floor of mouth and tongue. With the use of pre-op imaging to help planning, surgical excision is both diagnostic and therapeutic.

Comparison of C4-oxidizing and C1/C4-oxidizing AA9 LPMOs in substrate adsorption, H2O2-driven activity and synergy with cellulase on celluloses of different crystallinity

Two C1/C4-oxidizing AA9 lytic polysaccharide monooxygenases (AA9 LPMOs), AoLPMO9A and AoLPMO9B, and one C4-oxidizing AoLPMO9C from Aspergillus oryzae, were characterized and compared with the well-studied C4-oxidizing NcLPMO9C. NcLPMO9C and AoLPMO9C harboring carbohydrate-binding module 1 (CBM1) exhibited much stronger adsorption capacity than AoLPMO9A and B without CBM1. The binding affinity is crucial for the efficacy of H₂O₂ as cosubstrate and oxidative activity of AA9 LPMOs on crystalline cellulose. C4-oxidizing AA9 LPMOs had a striking boosting effect on cellobiohydrolase I (CBHI), while C1/C4-oxidizing AA9 LPMOs boosted CBHII and endoglucanase I (EGI) activity. Our results indicated that two types of AA9 LPMOs with different modularities and regioselectivities varied in cellulose adsorption, H₂O₂-driven activity and synergy with cellulase on celluloses of different crystallinity which could complement each other in lignocellulose degradation. C4-oxidizing AA9 LPMOs with CBM1 were particularly essential in cellulase cocktail due to high H₂O₂-driven activity and a striking boosting effect on CBHI.

AB0756 IMMUNE-MEDIATED BASIS FOR A PHASE 2A CLINICAL STUDY COMPARING RILZABRUTINIB VS GLUCOCORTICOIDS IN RITUXIMAB-REFRACTORY PATIENTS WITH IGG4-RELATED DISEASE

Background:

IgG4-related disease (IgG4-RD) is an immune-mediated disorder causing fibro-inflammatory lesions. Although the cause remains unknown, it may be driven by interactions between B lymphocytes and CD4+ cytotoxic and regulatory T cells and is characterized by an increase in short-lived plasmablasts, circulating antibodies, and macrophages. Standard therapy mainly includes glucocorticoids (GC), limited by toxicity with long-term use (> 6 mo), and to a lesser extent, immunosuppressives (eg, rituximab). Bruton tyrosine kinase (BTK) plays an important role in the activation of multiple immune effector cells such as B cells, mast cells, eosinophils, basophils, monocytes/macrophages, and neutrophils. Dysregulation of the activation of these immune cells results in autoimmune inflammation, tissue damage, and development of fibrosis. Rilzabrutinib is a highly selective oral BTK inhibitor that targets multiple pathways of innate and adaptive immunity (with direct effects on B-cell and FcR pathways) and has the potential to inhibit antigen presentation to autoreactive T cells.

Objectives:

To provide the biological rationale for rilzabrutinib in IgG4-RD.

Methods:

Rilzabrutinib has been evaluated in biochemical, in vitro studies, and in vivo models of inflammatory diseases. Additional support is provided by the phase 2 trial for oral rilzabrutinib in patients with pemphigus vulgaris and the phase 2 trial for oral rilzabrutinib in patients with immune thrombocytopenia (ITP).

Results:

Rilzabrutinib inhibited the activity of BTK and B-cell receptor in B cells (IC50 5-123 nM) and Fc gamma receptor in IgG/Fc gamma receptor-stimulated monocytes (IC50 56 nM) and blocked IgG- and IgM-mediated antibody production in enriched B cells when stimulated in T-cell dependent (anti-CD40+IL-21) and T-cell independent (TLR-9/CpG and TNP-LPS) pathways. The impact of rilzabrutinib on innate cell pathways was further confirmed by significant dose-dependent inhibition of macrophage and neutrophil-driven passive rat Arthus reaction (P < 0.01 vs vehicle) and antibody-induced murine ITP (P < 0.05 vs vehicle). In a 12-week phase 2 pemphigus vulgaris trial, 54% of patients achieved the primary endpoint, control of disease activity (CDA) on low-dose corticosteroids by week 4, and 73% achieved it by week 12. In the phase 2 trial of ITP patients (median 6 prior therapies), rilzabrutinib 400 mg bid showed rapid and sustained improvement in platelet counts and only grade 1/2-related adverse events1. In responders, platelet counts increased as early as day 8, potentially due to innate immune mechanisms. Collectively, results in both B and innate immune cells provide an initial basis for evaluating rilzabrutinib in IgG4-RD. The ongoing phase 2a study (NCT04520451) is investigating rilzabrutinib 400 mg bid (+tapered GC) vs GC control (3:1) for 12 weeks in IgG4-RD patients refractory to rituximab. The primary objective is to evaluate the safety and ability of rilzabrutinib to induce GC-free remission at week 12. Coupled with known preclinical/clinical findings, mechanistic analyses in this ongoing IgG4-RD study will profile B and other immune cell effects pre-/post-rilzabrutinib dosing to enhance the clinical understanding of rilzabrutinib in IgG4-RD.

Conclusion:

Studies of rilzabrutinib that show beneficial effects on both B-cell and innate cell pathways provide support for its therapeutic role in immune-mediated diseases and for targeting the underlying pathophysiological effects of IgG4-RD. Effective and safe therapies that rapidly induce and maintain clinical responses, while minimizing the need for continuous GC treatment, remain an unmet need for patients with IgG4-RD.

References:

[1]Kuter et al. Res Pract Thromb Haemost. 2020;4(suppl 1): PB1318.

Disclosure of Interests:

Li Long Employee of: Principia Biopharma, a Sanofi Company, Matthew Baker: None declared, Mollie Carruthers: None declared, Alireza Meysami: None declared, Robert Spiera Consultant of: research funding and personal fees for consulting from Chemocentryx, Formation Biologics, Roche-Genentech, and Sanofi, Grant/research support from: research funding fees from BMS, Boehringer Ingelheim, Corbus, GSK, and Inflarx; personal fees from AbbVie, CSL Behring, GSK, and Janssen, Mamatha Reddy Employee of: Principia Biopharma, a Sanofi Company, Marianne Kavanagh Employee of: Principia Biopharma, a Sanofi Company, Michelle Francesco Employee of: Principia Biopharma, a Sanofi Company, Claire Langrish Employee of: Principia Biopharma, a Sanofi Company, Ann Neale Employee of: Principia Biopharma, a Sanofi Company, Puneet Arora Employee of: Principia Biopharma, a Sanofi Company, John H. Stone Consultant of: research funding and personal fees for consulting from Principia and Sanofi

AB0809 PADUA PREDICTION SCORE COMBINED WITH SERUM ALBUMIN FOR THE IDENTIFICATION OF VENOUS THROMBOEMBOLISM OF HOSPITALIZED PATIENTS IN THE DEPARTMENT OF RHEUMATOLOGY

Background:

Venous thromboembolism (VTE) includes thrombotic disease of venous system, but primarily includes lower extremity deep vein thrombosis (DVT) and pulmonary embolism (PE). Population-based epidemiological studies have shown an association between systemic autoimmune diseases and VTE[1]. The Padua prediction score(PPS) is a new 20-point risk assessment model proposed by Professor Barbar et al[2] in 2010. A large number of researches have shown that low serum albumin concentration is associated with an increased risk of VTE [3],but there is a lack of studies on serum albumin in VTE, and there are no reports on PPS in rheumatology inpatients.

Objectives:

To investigate the status of VTE in patients in the department of rheumatology, and to explore the value of PPS combined with serum albumin in the identification of VTE in this patient population.

Methods:

Baseline data of inpatients in rheumatology department were collected at Sichuan Provincial People’s Hospital from September 2018 to September 2020. Occurrence of VTE was compared between high and low risk groups. PPSs were analyzed in VTE and non-VTE patients. Multivariate logistic regression was used to analyze the independent risk factors of VTE. The receiver operating characteristic curve was used to evaluate the probablity of value of rheumatic inpatients with VTE assessed by PPS,serum albumin and PPS with serum albumin. P<0.05 indicates that the difference was statistically significant.

Results:

A total of 2282 patients were included in this study, and 50(2.2%) had symptomatic VTE. Among the symptomatic VTE cases,38(1.6%) had DVT only,8(0.4%) had PE only, and 4(0.2%) were diagnosed with DVT and PE. PPSs in VTE and non-VTE groups were 3.00(2.00~6.00) and2.00(1.00~2.00) respectively (P< 0.05). One hundred and eighty-eight cases was divided into high-risk group of VTE (PPS≥4), while 2094 cases (PPS<4) were in the low-risk group. Logistic regression analysis showed that known thrombophilic condition, history of VTE, reduced mobility, and D-dimer were independent risk factors of VTE in rheumatology patients, the odd ration(OR) values were 161.90, 26.08, 8.73,and1.04. Serum albumin was the independent protection factor [OR= 0.92(95%CI:0.87~0.98)]. The AUC of PPS model, serum albumin model and the combined predictive model were 0.77, 0.75, 0.84, respectively. The difference between the combined prediction model and PPS model was statistically significant (Z=3.813, P<0.05). The optimal sensitivity of PPS and serum albumin models is 60%, 82%, respectively, and the optimal specificity of is 82.5%,58.6%, respectively. The combination model corresponds to a sensitivity of 62% and a specificity of 90.4%.

Conclusion:

The incidence of symptomatic VTE was relatively higher in hospitalized patients in rheumatology department. Serum albumin was the protective factor. The combination of albumin and PPS can improve the accuracy of screening for VTE in rheumatology in-patients.

References:

[1]Tamaki H,Khasnis A.Venous thromboembolism in systemic autoimmune diseases: A narrative review with emphasis on primary systemic vasculitides.[J].Vasc Med, 2015, 20: 369-76.

[2]Barbar S, Noventa F, Rossetto V,et al. A risk assessment model for the identification of hospitalized medical patients at risk for venous thromboembolism: the Padua Prediction Score[J]. J Thromb Haemost,2010,8(11):2450–2457.

[3]Kunutsor SK,Seidu S,Katechia DT et al. Inverse association between serum albumin and future risk of venous thromboembolism: interrelationship with high sensitivity C-reactive protein.[J].Ann Med, 2018, 50: 240-248.

Disclosure of Interests:

None declared

Managing multidrug-resistant tuberculosis in South Africa: a budget impact analysis

SETTING: In South Africa prior to 2016, the standard treatment regimen for multidrug- and rifampicin-resistant tuberculosis (MDR/RR-TB) was 24 months long and required daily injectable aminoglycoside (IA) treatment during the first 6 months. Recent evidence supports the replacement of IA with well-tolerated oral bedaquiline (BDQ) and a shortened 9-12 month regimen.DESIGN: Using a Markov model, we analyzed the 5-year budgetary impact and cost per successful treatment outcome of four regimens: 1) IA long-course, 2) oral long-course, 3) IA short-course, and 4) oral short-course. We used the South African MDR/RR-TB case register (2013-2015) to assess treatment outcomes for the then-standard IA long-course. Data on the improvement in outcomes for BDQ-based regimens were based on the literature. Costs were estimated from the provider perspective using costs incurred to provide decentralized treatment for MDR-TB at a Johannesburg hospital.RESULTS: Based on our analysis, by 2023, the cost/successful outcome for the four regimens was respectively 1) US$7374, 2) US$7860, 3) US$5149, and 4) US$4922. The annual total cost of each regimen was US$37 million, US$43 million, US$26 million, and US$28 million.CONCLUSION: Despite the high cost of BDQ, a BDQ-based shortened regimen for the treatment of MDR/RR-TB will result in improved treatment outcomes and cost savings for South Africa.

Dissecting the Role of VicK Phosphatase in Aggregation and Biofilm Formation of Streptococcus mutans

VicRK (WalRK or YycFG) is a conserved 2-component regulatory system (TCS) that regulates cell division, cell wall biosynthesis, and homeostasis in low-GC Gram-positive bacteria. VicRK is also associated with biofilm formation of Streptococcus mutans on the tooth surface as it directly regulates the extracellular polysaccharide (EPS) synthesis. Of the 2 components, VicK possesses both autokinase and phosphatase activities, which regulate the phosphorylation and dephosphorylation of the regulator VicR in response to environmental cues. However, the dual mechanism of VicK as the autokinase/phosphatase in regulating S. mutans' responses is not well elucidated. Previously, it has been shown that the phosphatase activity depends on the PAS domain and residues in the DHp domain of VicK in S. mutans. Specifically, mutating proline at 222 in the PAS domain inhibits VicK phosphatase activity. We generated a VicK^P222A mutant to determine the level of VicR-P in the cytoplasm by Phos-tag sodium dodecyl sulfate polyacrylamide gel electrophoresis. We show that in VicK^P222A phosphatase, attenuation increased phosphorylated VicR (VicR-P) that downregulated glucosyltransferases, gtfBC, thereby reducing the synthesis of water-insoluble polysaccharides (WIS-EPS) in the biofilm. In addition, VicK^P222A presented as long-rod cells, reduced growth, and displayed asymmetrical division. A major adhesin of S. mutans, SpaP was downregulated in VicK^P222A, making it unable to agglutinate in saliva. In summary, we have confirmed that VicK phosphatase activity is critical to maintain optimal phosphorylation status of VicR in S. mutans, which is important for cell growth, cell division, EPS synthesis, and bacterial agglutination in saliva. Hence, VicK phosphatase activity may represent a promising target to modulate S. mutans' pathogenicity.

A highly xyloglucan active lytic polysaccharide monooxygenase EpLPMO9A from Eupenicillium parvum 4-14 shows boosting effect on hydrolysis of complex lignocellulosic substrates

The recently identified lytic polysaccharide monooxygenases (LPMOs) are important auxiliary proteins which contribute to lignocellulose biodegradation by oxidatively cleaving the glycosidic bonds in cellulose and other polysaccharides. The vast differences in terms of substrate specificity and regioselectivity within LPMOs provide us new possibilities to find promising candidates for the use in enzyme cocktails in biorefinery applications. In this study, a highly xyloglucan active family AA9 lytic polysaccharide monooxygenase EpLPMO9A was identified from Eupenicillium parvum 4-14. EpLPMO9A exhibited a mixed C1/C4 oxidative cleavage activity on cellulose and xyloglucan with a broad range of pH stability and good thermal stability at 40 °C. It showed a higher boosting effect on the enzymatic saccharification of complex lignocellulosic substrates associated with xyloglucan than on the lignocellulosic substrates without xyloglucan particularly in low commercial cellulase dosage cases. The oxidative cleavage of xyloglucan by EpLPMO9A may facilitate to open up the sterical hindrance of cellulose by xyloglucan and thereby increase accessibility for cellulase to lignocellulosic substrates. The discovery of more and more hemicellulose-active LPMOs and their contribution to breaking down the barriers by oxidatively acting on hemicellulose may expand our knowledge for their functions of LPMOs in lignocellulose biodegradation.

Characterization and functional analysis of two novel thermotolerant α-L-arabinofuranosidases belonging to glycoside hydrolase family 51 from Thielavia terrestris and family 62 from Eupenicillium parvum

Abstract

Arabinofuranose substitutions on xylan are known to interfere with enzymatic hydrolysis of this primary hemicellulose. In this work, two novel α-l-arabinofuranosidases (ABFs), TtABF51A from Thielavia terrestris and EpABF62C from Eupenicillium parvum, were characterized and functionally analyzed. From sequences analyses, TtABF51A and EpABF62C belong to glycoside hydrolase (GH) families 51 and 62, respectively. Recombinant TtABF51A showed high activity on 4-nitrophenyl-α-l-arabinofuranoside (83.39 U/mg), low-viscosity wheat arabinoxylan (WAX, 39.66 U/mg), high-viscosity rye arabinoxylan (RAX, 32.24 U/mg), and sugarbeet arabinan (25.69 U/mg), while EpABF62C preferred to degrade arabinoxylan. For EpABF62C, the rate of hydrolysis of RAX (94.10 U/mg) was 2.1 times that of WAX (45.46 U/mg). The optimal pH and reaction temperature for the two enzymes was between 4.0 and 4.5 and 65 °C, respectively. Calcium played an important role in the thermal stability of EpABF62C. TtABF51A and EpABF62C showed the highest thermal stabilities at pH 4.5 or 5.0, respectively. At their optimal pHs, TtABF51A and EpABF62C retained greater than 80% of their initial activities after incubation at 55 °C for 96 h or 144 h, respectively. ¹H NMR analysis indicated that the two enzymes selectively removed arabinose linked to C-3 of mono-substituted xylose residues in WAX. Compared with the singular application of the GH10 xylanase EpXYN1 from E. parvum, co-digestions of WAX including TtABF51A and/or EpABF62C released 2.49, 3.38, and 4.81 times xylose or 3.38, 1.65, and 2.57 times of xylobiose, respectively. Meanwhile, the amount of arabinose released from WAX by TtABF51A with EpXYN1 was 2.11 times the amount with TtABF51A alone.

Key points

• Two novel α-l-arabinofuranosidases (ABFs) displayed high thermal stability.

• The thermal stability of GH62 family EpABF62C was dependent on calcium.

• Buffer pH affects the thermal stability of the two ABFs.

• Both ABFs enhance the hydrolysis of WAX by a GH10 xylanase.

Electronic supplementary material

The online version of this article (10.1007/s00253-020-10867-7) contains supplementary material, which is available to authorized users.

Alkaline organosolv pretreatment of different sorghum stem parts for enhancing the total reducing sugar yields and p-coumaric acid release

BACKGROUND

The sorghum stem can be divided into the pith and rind parts with obvious differences in cell type and chemical composition, thus arising the different recalcitrance to enzyme hydrolysis and demand for different pretreatment conditions. The introduction of organic solvents in the pretreatment can reduce over-degradation of cellulose and hemicellulose, but significance of organic solvent addition in pretreatment of different parts of sorghum stem is still unclear. Valorization of each component is critical for economy of sorghum biorefinery. Therefore, in this study, NaOH-ethanol pretreatment condition for different parts of the sorghum stem was optimized to maximize p-coumaric acid release and total reducing sugar recovery.

RESULT

Ethanol addition improved p-coumaric acid release and delignification efficiency, but significantly reduced hemicellulose deconstruction in NaOH-ethanol pretreatment. Optimization using the response surface methodology revealed that the pith, rind and whole stem require different NaOH-ethanol pretreatment conditions for maximal p-coumaric acid release and xylan preservation. By respective optimal NaOH-ethanol pretreatment, the p-coumaric acid release yields reached 94.07%, 97.24% and 95.05% from pith, rind and whole stem, which increased by 8.16%, 8.38% and 8.39% compared to those of NaOH-pretreated samples. The xylan recoveries of pith, rind and whole stem reached 76.80%, 88.46% and 85.01%, respectively, which increased by 47.75%, 15.11% and 35.97% compared to NaOH pretreatment. Adding xylanase significantly enhanced the enzymatic saccharification of pretreated residues. The total reducing sugar yields after respective optimal NaOH-ethanol pretreatment and enzymatic hydrolysis reached 84.06%, 82.29% and 84.09% for pith, rind and whole stem, respectively, which increased by 29.56%, 23.67% and 25.56% compared to those of NaOH-pretreated samples. Considering the separation cost of the different stem parts, whole sorghum stem can be directly used as feedstock in industrial biorefinery.

CONCLUSION

These results indicated that NaOH-ethanol is effective for the efficient fractionation and pretreatment of sorghum biomass. This work will help to understand the differences of different parts of sorghum stem under NaOH-ethanol pretreatment, thereby improving the full-component utilization of sorghum stem.

CaXyn30B from the solventogenic bacterium Clostridium acetobutylicum is a glucuronic acid-dependent endoxylanase

Objective

We previously described the structure and activity of a glycoside hydrolase family 30 subfamily 8 (GH30-8) endoxylanase, CaXyn30A, from Clostridium acetobutylicum which exhibited novel glucuronic acid (GA)-independent activity. Immediately downstream from CaXyn30A is encoded another GH30-8 enzyme, CaXyn30B. While CaXyn30A deviated substantially in the highly conserved β7-α7 and β8-α8 loop regions of the catalytic cleft which are responsible for GA-dependence, CaXyn30B maintains these conserved subfamily 8 amino acid residues thus predicting canonical GA-dependent activity. In this report, we show that CaXyn30B functions as a canonical GA-dependent GH30-8 endoxylanase in contrast to its GA-independent neighbor, CaXyn30A.

Results

A clone expressing the catalytic domain of CaXyn30B (CaXyn30B-CD) exhibited GA-dependent endoxylanase activity. Digestion of glucuronoxylan generated a ladder of aldouronate limit products as anticipated for canonical GA-dependent GH30-8 enzymes. Unlike the previously described CaXyn30A-CD, CaXyn30B-CD showed no activity on arabinoxylan or the generation of appreciable neutral oligosaccharides from glucuronoxylan substrates. These results are consistent with amino acid sequence comparisons of the catalytic cleft and phylogenetic analysis.

FRI0443 CLINICAL CHARACTERISTICS AND RELATED FACTORS OF COMMON RHEUMATIC DISEASES COMPLICATED WITH TUBERCULOSIS INFECTION

Background:

Rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and syndrome(SS) are common rheumatic diseases with high incidence. Patients with those rheumatic diseases are at high risk of tuberculosis (TB) infection. However, manifestations can be atypical and easily confused with those of rheumatic disease itself. For those patients, diagnosis is usually much more difficult and further make treatment delayed. Sometimes it may lead to mistreatment. Therefore, it is important to recognize the clinical characteristics of those patients.

Objectives:

To explore the clinical characteristics and high risk factors of common systemic rheumatism complicated with tuberculosis infection.

Methods:

A total of 3,906 cases of RA, SLE, and SS common systemic rheumatism diagnosed in the People’s Hospital of Sichuan Province from January 2007 to January 2017 were collected with carefully exclusion with other infectious diseases and neoplastic disease. One hundred and five patients with TB were included as infection group, including 42 cases of RA, 41 cases of SLE, and 22 cases of SS. In the control group, 84 patients with RA, 82 patients with SLE, and 44 patients with SS were randomly selected from the corresponding rheumatoid non-infected patients hospitalized during the same period.

Results:

Fever was the most common symptom among 42 cases of RA, 41 cases of SLE, and 22 cases of SS with TB, accounting for 83.3%, 92.7%, and 68.2%, respectively. Cough, weight loss or fatigue was less common. For 41 cases of SLE and 22 cases of SS with TB, the proportion of pulmonary was 46.3%, 59.01%, respectively.In TB infection group, 27 cases of RA, 21 cases of SLE, and 13 cases of SS with TB had two or more chest CT findings, accounting for 59%, 57%, 62%, respectively. Lesions located in the posterior or posterior segment which TB usually affected were 9 cases(33.3%),9cases(42.9%),6cases(27.2%),respectively.The daily average dose of hormones within 1 year in TB infection group was higher than that in the control group (P<0.05). For SLE patients, lower counts of CD4+TL were found in TB infection group (P<0.05), while no such differences were found in RA and SS group.

Conclusion:

Patients with RA who have TB infection are mainly pulmonary TB. For SLE and SS patients, the chance of pulmonary tuberculosis and extra-pulmonary tuberculosis is similar.Symptoms of RA, SLE, SS with TB, such as fever, cough, weight loss, fatigue, are similar with the primary disease or other infection. Chest imaging is diversity. It is difficult to diagnose.Daily average dose of hormone within one year may be a common risk factor for RA, SLE and SS patients with TB. Decreased CD4+TL may also be a risk factor for SLE patients with TB.

References:

[1]Cantini F, Nannini C, Niccoli L, et al. Risk of Tuberculosis Reactivation in Patients with Rheumatoid Arthritis, Ankylosing Spondylitis, and Psoriatic Arthritis Receiving Non-Anti-TNF-Targeted Biologics[J]. Mediators of Inflammation, 2017, 2017(6):1-15.

[2]Ruangnapa K, Dissaneewate P, Vachvanichsanong P. Tuberculosis in SLE patients: rare diagnosis, risky treatment.[J]. Clinical & Experimental Medicine, 2015, 15(3):429-432.

[3]Manuela D F, Bruno L, Martina S, et al. Lung Infections in Systemic Rheumatic Disease: Focus on Opportunistic Infections[J]. International Journal of Molecular Sciences, 2017, 18(2):293-315.

[4]Disseminated tuberculosis masquerading as a presentation of systemic lupus erythematosus.Li JC, Fong W, Wijaya L, Leung YY.Int J Rheum Dis. 2017 Oct 2. doi: 10.1111/1756-185X.13195.

[5]Handa R, Upadhyaya S, Kapoor S, et al. Tuberculosis and biologics in rheumatology: India – A special situation[J]. International Journal of Rheumatic Diseases, 2017, 51(2):115.

Disclosure of Interests:

None declared

SAT0209 PREVALENCE AND RELATED FACTORS OF SLEEP DISTURBANCE IN PATIENTS WITH PRIMARY SJÖGREN’S SYNDROME

Background:

The incidence of primary Sjögren’s syndrome(pSS) is increasing gradually,and it was ranking second among connective tissue diseases(CTDs)in China.Studies recently have shown that many patients with various CTDs have sleep disturbances,which seriously degraded the patient’s quality of life.As well known, Sleep is an important physiological process to maintain human metabolism, tissue repair,and homeostasis. At present,there are relatively several studies on sleep quality in patients with Rheumatoid arthritis(RA)and Systemic lupus erythematosus(SLE),but less reports on pSS in China have been published.Therefore,it is important to explore the quality of sleep and its influencing factors in such patients.

Objectives:

The purpose of this study is to evaluate the quality of sleep and related factors in China Mainland patients with primary Sjögren’s syndrome(pSS),and to provide reference and theoretical basis for constructing targeted sleep interventions and improve their quality of life.

Methods:

A all of 103 pSS patients and 40 matched healthy controls were enrolled in a comparative study of sleep quality using the Pittsburgh Sleep Quality Index(PSQI),and demographic,clinical,and laboratory data were collected from them.The patients completed questionnaires on the European League Against Rheumatism (EULAR)SS Patient Reported Index(ESSPRI), EULAR SS Disease Activity Index (ESSDAI),Xerostomia inventory(XI)with the help of researchers,Pain and fatigue were evaluated with a 100-mm visual analogue scale(VAS).Generalized Anxiety Disorder(GAD-7) and Patient Health Questionnaire(PHQ-9) were used to assess anxiety and depression separately,and whether they have autonomic symptoms (such as sweating, palpitations.)will be asked.

Results:

The PSQI score and the frequency of poor sleep quality(PSQI>7) were higher in the pSS patients (11.60±5.03,71.8%)than the healthy controls(5.98±3.85,25%).Poor sleepers had a significantly higher GAD-7,PHQ-9,XI,ESSPRI,pain and fatigue VAS,and longer disease duration than good sleepers.Additionally, poor sleepers show more frequent autonomic symptoms.Sleep quality of patients with pSS was positive correlated with GAD-7,PHQ-9,XI,ESSPRI,pain and fatigueVAS scores,but no correlation with disease activity.Meanwhile,depression is a independent factor of sleep quality.

Conclusion:

Our study showed that the sleep disturbance seen in patients with pSS may contribute to the depression associated with this disease,Future research should investigate that whether antidepressant treatment improve sleep and directly improve quality of life.

References:

[1]AustadC, Kvien TK, Olsen I C.Sleep disturbance in patients with rheumatoid arthritis is related to fatigue, disease activity,and other patient-reported outcomes[J]. Scandinavian journal of rheumatology, 2017, 46(2): 95-103.

[2]Lewis I, Hackett K L,Ng W F,et al.A two-phase cohort study of the sleep phenotype within primary Sjögren’s syndrome and its clinical correlates[J].Clinical and experimental rheumatology,2019,37(3):78-82.

[3]Chung S W, Hur J, Ha Y J, et al. Impact of sleep quality on clinical features of primary Sjögren’s syndrome[J]. The Korean journal of internal medicine, 2019,34(5):1154.

[4]Liu X, Tang M, Hu L. Reliability and validity of the Pittsburgh sleep quality index[J].Chinese journal of psychiatry,1996,29:103-107.

[5]Grabovac I,Haider S, Berner C,et al.Sleep quality in patients with rheumatoid arthritis and associations with pain, disability, disease duration, and activity[J].Journal of clinical medicine,2018,7(10):336.

Disclosure of Interests:

None declared

The COVID-19 effect: number of patients presenting to The Mid Yorkshire Hospitals OMFS team with dental infections before and during The COVID-19 outbreak

This paper investigates the effect of the COVID-19 outbreak and closure of dental practices on the frequency and severity of dental infections presenting in our emergency department. We compared the mean number of daily emergency department referrals for dental abscesses in the two weeks prior to and following the Chief Dental Officer's statement advising general dental practitioners to cease routine appointments, the mean number decreased from 1 to 0.37. In contrast, the severity and requirement for admission of these infections rose from 35% to 80%. This highlights the importance of the provision of local urgent dental centres during the COVID-19 outbreak in order to reduce pressure on secondary and tertiary care centres.

[Expression of HLA-DP in patients with neuromyelitis optica spectrum disorders]

Objective: To investigate the effect of HLA-DP gene expression on the susceptibility and disease status of neuromyelitis optica spectrum disorders (NMOSD). Methods: A total of 86 NMOSD patients (52 in acute phase and 34 in remission phase), 52 multiple sclerosis (MS) patients (20 in acute phase and 32 in remission phase) diagnosed in Department of Neurology, the Third Affiliated Hospital of Sun Yat-sen University and 29 healthy controls were enrolled prospectively. Genotyping of HLA-DP was performed. The expression levels of HLA-DP molecules in peripheral blood B cells and monocytes were measured by flow cytometry. The transcription levels of HLA-DPB1 mRNA in peripheral blood mononuclear cells (PBMC) were measured by real time-PCR. The results were compared among different groups Results: There was no statistically significant difference of the distributions of HLA-DPB1*0501/HLA-DPB1*0501, HLA-DPB1*0501/X and X/X genotypes and the frequencies of allele of HLA-DPB1*0501 among NMOSD, MS patients and healthy controls (P=0.96 and 0.71, respectively). The expression levels of HLA-DP on the surface of B cells in NMOSD patients, especially in remission phase patients, were significantly higher than those in healthy controls(212±328 and 374±394 vs 55±57, P=0.049 and 0.002, respectively). The expression levels of HLA-DP on the surface of monocytes in NMOSD patients in acute phase were significantly higher than those in healthy controls(158±175 vs 65±90, P=0.025). The transcription levels of PMBC HLA-DPB1 mRNA in acute phase and remission phase of NMOSD patients were significantly higher than those in healthy controls (3.0±1.4 and 2.9±1.3 vs 1.5±1.4, P=0.000 and 0.003, respectively). The expression levels of HLA-DP molecules on the surface of peripheral blood B cells and monocytes and the transcription levels of PMBC HLA-DPB1 mRNA in MS patients at the acute and remission stages were not significantly different from those in healthy controls. The expression levels of HLA-DP molecules on the surface of B cells in patients with HLA-DPB1*0501/HLA-DPB1*0501, HLA-DPB1*0501/X and X/X genotypes were statistically different (P=0.017). Conclusion: HLA-DP gene transcription and molecular expression levels in antigen presenting cells may affect the susceptibility and disease status of NMOSD patients, while HLA-DPB1*0501 allele may affect the transcription and molecular expression levels of HLA-DP gene in antigen presenting cells.

[The association between the whole blood riboflavin level and the occurrence, development and prognosis of esophageal squamous cell carcinoma]

Objective: To investigate the association between the whole blood riboflavin level and the occurrence, development and prognosis of esophageal squamous cell carcinoma (ESCC) in China. Methods: From March 2014 to September 2018, ESCC patients from three hospitals (the Affiliated Hospital of Medical College of Shantou University, Shantou Central Hospital in Southern Chaoshan area and First Affiliated Hospital of Zhengzhou University in Northern Taihang Mountain) were selected as a case group; non-esophageal patients who had a physical examination were selected as a control group. The case and control group were paired by age (±5 years) and a 1:1 ration. A total of 1 528 subjects were enrolled including 764 patients in the case group and 764 patients in the control group. About 3-5 ml venous blood samples were collected, and the erythrocyte glutathione reductase activity coefficient (GRAC) was measured to assess the whole blood riboflavin level. A multivariate conditional logistic regression model was used to analyze the association between the GRAC and the risk of ESCC. The association between the GRAC and the prognosis of ESCC was analyzed by using Cox proportional risk regression model based on 288 patients with complete survival data. They were divided into two groups, the high GRAC group (GRAC≥7.87) group and the low GRAC group (GRAC<7.87) according to the strongest correlation between the total survival time, survival outcome and GRAC (GRAC=7.87). Results: Among the 1 528 patients, 958 patients were from Southern Chaoshan area, including 479 patients in the case group with an average age about (59.90±9.34) years and 479 patients in the control group with an average age about (59.55±8.77) years. Other 570 patients were from Northern Taihang Mountain area, including 285 patients in the case group with an average age (58.39±5.19) years and 285 patients in the control group with an average age about (58.74±4.57) years. The multivariate conditional logistic regression showed that the OR (95%CI) of the GRAC and the risk of ESCC was 1.009 (0.998-1.019). The Cox proportional hazard regression model analysis showed that the HR (95%CI) of the high GRAC group was 1.712 (1.034-2.824) compared with the low GRAC group in the 50-70 years group. Conclusion: The whole blood riboflavin level might not be associated with the occurrence of ESCC. The high whole blood riboflavin level would be more beneficial to the prognosis of ESCC patients aged 50-70 years.

Characterization of a D-lyxose isomerase from Bacillus velezensis and its application for the production of D-mannose and L-ribose

D-Mannose and L-ribose are two important monosaccharides, which have attracted public attention recently because of their great application potentials in food, cosmetic and pharmaceutical industries. Sugar isomerases catalyze the sugar isomerization and therefore can be used as the biocatalysts for production of the high-value sugars from inexpensive sugars. L-arabinose isomerase catalyzes the conversion of L-arabinose to L-ribulose, while D-lyxose isomerase catalyzes L-ribulose and D-fructose to L-ribose and D-mannose, respectively. In this paper, a putative D-LI from Bacillus velezensis (BvLI) was identified, characterized and used to produce D-mannose and L-ribose from D-fructose and L-arabinose, respectively. The recombinant BvLI exhibited a maximum activity at 55 °C and pH 6.5, in the presence of 0.1 mM Co²⁺. Approximately 110.75 g/L D-mannose was obtained from 500 g/L D-fructose in 6 h by the recombinant BvLI, and approximately 105 g/L L-ribose was obtained from 500 g/L L-arabinose in 8 h by the successive biocatalysis of L-arabinose isomerase from Bacillus licheniformis (BlAI) and BvLI.

[Clinical analysis of 555 outpatients with hand, foot and mouth diseases caused by different enteroviruses]

Objective: To study the clinical characteristics of outpatients with hand, foot and mouth disease (HFMD) caused by different serotypes of enteroviruses. Methods: This was a prospective study. From February 2017 to March 2018, 563 outpatients with HFMD were enrolled by systematic sampling in the Department of Infectious Diseases, Henan Children's Hospital. Throat swabs were collected to determine the serotypes via PCR. Demographic, clinical, and laboratory data were collected by standard questionnaire. All cases were followed up twice at 2 and 9 weeks after the initial outpatient visit through telephone interview. A total of 563 cases were enrolled and 555 (98.6%) cases were positive for human enteroviruses, including 338 (60.9%) males. Analyses were stratified by enterovirus serotypes, Chi square test or Fisher's exact test, Rank sum test was used for comparison among different groups. Results: The age of 555 cases was 24.2 (16.4, 41.3) months. Among them 44.0% (224 cases) were identified as coxsackievirus (CV)-A6, while 189 cases, 35 cases, 14 cases and 73 cases were identified as CV-A16, enterovirus (EV)-A71, CV-A10 and other serotypes, respectively. Fever (≥37.5 ℃) was present in 51.4% (285/555) of laboratory confirmed cases. The proportions of fever in cases of CV-A6 (68.9%(168/244)) and CV-A10 (12/14) were significantly higher than those in cases of CV-A16 (31.7%(60/189),χ(2)=57.344,14.313,both P=0.000), other serotypes (43.8%(32/73),χ(2)=15.101 and 8.242, P=0.000 and 0.004) and EV-A71 (37.1%(13/35), χ(2)=13.506 and 9.441, P=0.000 and 0.002) respectively. There was no significant difference between CV-A6 and CV-A10 in presentation of fever (χ(2)=1.785, P=0.182). There were 359 cases (64.7%) with eruptions in mouth, hands, feet and buttocks. Cases infected with EV-A71 had the highest proportions (74.3%(26/35)) of rash emerging simultaneously in mouth, hands, feet, and buttocks. The proportion in cases of CV-A16, CV-A6, CVA10 and other serotype were 73.5% (139/189), 61.9% (151/244), 7/14 and 49.3% (36/73), respectively. The proportion of rash on other parts of body, such as face, limbs or torso in cases infected with CV-A6 (16.8% (41/244)) was the higherest and the proportion in cases of CV-A16, EV-A71, CV-A10 or other serotypes were 8.5% (16/189) , 5.7% (2/35) , 1/14, 6.8% (5/73) , respectively. None of these cases developed serious complications. Desquamation occurred in 45.5% (179/393) cases 7.5 (5.0, 9.0) days after disease onset and 13.5% (53/393) cases showed onychomadesis 31.0 (18.0, 33.5) days after disease onset. The proportion of desquamation and onychomadesis associated with CV-A6 (64.2% (95/148) and 31.8% (47/148)) was significantly higher than CV-A16 (31.8% (49/154) and 1.3% (2/154), χ(2)=33.601 and 52.482, both P=0.000) and other serotypes (38.0%(19/50) and 6.0%(3/50),χ(2)=10.236 and 12.988, P=0.001 and 0.000). Desquamation appeared more in cases of CV-A6 than in cases of CV-A10 (2/11,χ(2)=9.386, P=0.002), with the proportion of onychomadesis higher in CV-A6 than in EV-A71 (3.3% (1/30),χ(2)=11.088, P=0.001). Conclusion: Clinical manifestation such as fever, rash emerging parts, desquamation and onychomadesis are different among outpatient HFMD cases infected with CV-A16, CV-A6, EV-A71, CV-A10 and other enteroviruses.

Expression and Characterization of Carotenoid Cleavage Oxygenases From Herbaspirillum seropedicae and Rhodobacteraceae bacterium Capable of Biotransforming Isoeugenol and 4-Vinylguaiacol to Vanillin

HsCCO and RbCCO from Herbaspirillum seropedicae and Rhodobacteraceae bacterium were selected and characterized from five putative bacterial carotenoid cleavage oxygenase gene sequences, due to merits in expression solubility and catalytic properties. Both enzymes can convert 4-vinylguaiacol and isoeugenol to vanillin. HsCCO showed maximum activity at 40°C and pH 7.0 and was stable at pH 6.5-10 and temperature around 25°C, retaining over 90 and 80% of initial activity, respectively. RbCCO showed maximum activity at 35°C and pH 9.0 and was stable at pH 6-11 and temperatures of 25-30°C, retaining over 80% of initial activity. The kinetic constants K _m of HsCCO for isoeugenol and 4-vinylguaiacol were 1.55 and 1.65 mM and V _max were 74.09 and 27.91 nmol min^-1 mg^-1, respectively. The kinetic constants K _m of RbCCO for isoeugenol and 4-vinylguaiacol were 2.24 and 0.85 mM and V _max were 76.48 and 19.96 nmol min^-1 mg^-1, respectively. The transformed Escherichia coli cells harboring HsCCO converted isoeugenol and 4-vinylguaiacol at molar conversion yields of 80 and 55% and the maximum vanillin concentrations were up to 1.22 and 0.84 g L^-1, respectively. Comparably, the molar conversion yields of the transformed E. coli cells harboring RbCCO against isoeugenol 4-vinylguaiacol were 75 and 58%, and the maximum vanillin yields were up to 1.14 and 0.88 g L^-1, respectively.

Bioproduction of High-Concentration 4-Vinylguaiacol Using Whole-Cell Catalysis Harboring an Organic Solvent-Tolerant Phenolic Acid Decarboxylase From Bacillus atrophaeus

The compound 4-vinyl guaiacol (4-VG) is highly valued and widely applied in the pharmaceutical, cosmetic, and food industries. The bioproduction of 4-VG from ferulic acid (FA) by non-oxidative decarboxylation using phenolic acid decarboxylases is promising but has been hampered by low conversion yields and final product concentrations due to the toxicities of 4-VG and FA. In the current study, a new phenolic acid decarboxylase (BaPAD) was characterized from Bacillus atrophaeus. The BaPAD possessed excellent catalytic activity and stability in various organic solvents. Whole Escherichia coli cells harboring intracellular BaPAD exhibited greater tolerances to FA and 4-VG than those of free BaPAD. A highly efficient aqueous-organic biphasic system was established using 1-octanol as the optimal organic phase for whole-cell catalysis. In this system, a very high concentration (1580 mM, 237.3 g/L) of 4-VG was achieved in a 2 L working volume bioreactor, and the molar conversion yield and productivity reached 98.9% and 18.3 g/L/h in 13 h, respectively.

BMPRII deficiency impairs apoptosis via the BMPRII-ALK1-BclX-mediated pathway in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a devastating cardiovascular disorder characterized by the remodelling of pre-capillary pulmonary arteries. The vascular remodelling observed in PAH patients results from excessive proliferation and apoptosis resistance of pulmonary arterial smooth muscle cells (PASMCs) and pulmonary arterial endothelial cells (PAECs). We have previously demonstrated that mutations in the type II receptor for bone morphogenetic protein (BMPRII) underlie the majority of the familial and inherited forms of the disease. We have further demonstrated that BMPRII deficiency promotes excessive proliferation and attenuates apoptosis in PASMCs, but the underlying mechanisms remain unclear. The major objective of this study is to investigate how BMPRII deficiency impairs apoptosis in PAH. Using multidisciplinary approaches, we demonstrate that deficiency in the expression of BMPRII impairs apoptosis by modulating the alternative splicing of the apoptotic regulator, B-cell lymphoma X (Bcl-x) transcripts: a finding observed in circulating leukocytes and lungs of PAH subjects, hypoxia-induced PAH rat lungs as well as in PASMCs and PAECs. BMPRII deficiency elicits cell specific effects: promoting the expression of Bcl-xL transcripts in PASMCs while inhibiting it in ECs, thus exerting differential apoptotic effects in these cells. The pro-survival effect of BMPRII receptor is mediated through the activin receptor-like kinase 1 (ALK1) but not the ALK3 receptor. Finally, we show that BMPRII interacts with the ALK1 receptor and pathogenic mutations in the BMPR2 gene abolish this interaction. Taken together, dysfunctional BMPRII responsiveness impairs apoptosis via the BMPRII-ALK1-Bcl-xL pathway in PAH. We suggest Bcl-xL as a potential biomarker and druggable target.