A case of primary breast angiosarcoma diagnosed by multimodal ultrasound imaging with literature review.

Primary Breast Angiosarcoma (PBA) is an exceptionally rare form of breast cancer, accounting for less than 0.05% of all breast cancers. It is characterized by a high level of malignancy, invasiveness, and has a prognosis that is typically poor. The lack of distinctive clinical features makes it prone to underdiagnosis and misdiagnosis. This study retrospectively examines a case utilizing multimodal ultrasound imaging techniques (including 2D ultrasound, contrast-enhanced ultrasound, and ultrasound elastography) for diagnosing PBA. Furthermore, the study reviews relevant literature to summarize the ultrasound characteristics of PBA, with the aim of improving understanding of this elusive condition.

The inhibitory impact of Schisandrin on inflammation and oxidative stress alleviates LPS-induced acute kidney injury.

Inflammation and oxidative stress (OS) are the major pathogenic characteristics of acute kidney injury (AKI). Studies have shown that Schisandrin (Sch) could regulate inflammatory disease. However, the function and mechanism of Sch in AKI progression are still unknown. Here, we investigated Sch's potential effects and mechanism on mice's renal damage and macrophages induced by lipopolysaccharide (LPS). Sch decreased LPS-induced inflammatory factor production while increasing the activity of related antioxidant enzymes in macrophages and mouse kidney tissues. Hematoxylin and eosin staining revealed that Sch may have the ability to profoundly inhibit inflammatory cell invasion and tissue damage caused by LPS in renal tissue. Furthermore, Western blot and immunohistochemical studies showed that Sch exerted its effects mainly through up-regulation of nuclear factor erythroid 2-related factor 2/heme oxygenase-1 and inhibition of Toll-like receptor 4‒mitogen-activated protein kinases/nuclear factor-kappa B pathways. Collectively, this study illustrates that Sch suppresses LPS-stimulated AKI by descending inflammation and OS, illuminating prospective AKI treatment options.

Abdominal abscess caused by Raoultella ornithinolytica secondary to postoperative gastric fistula: case report and review of literature.

BACKGROUND: In recent years, Raoultella ornithinolytica (R. ornithinolytica) have attracted clinical attention as a new type of pathogen. A wide range of infections with these germs is reported, and commonly found in urinary tract infections, respiratory infections, and bacteremia. CASE PRESENTATION: We report the case of an elderly woman with liver abscess, choledocholithiasis and cholangitis, who developed gastric fistula and abdominal abscess after underwent choledocholithotomy, and R. ornithinolytica were isolated from the abdominal drainage fluid. The patient was treated with meropenem and levofloxacin and had a good outcome. CONCLUSIONS: To the best of our knowledge, case of isolating R. ornithinolytica from a patient with non-viscerally abdominal abscess was extremely rare. We share a case of a woman with non-viscerally abdominal abscess secondary to postoperative gastric fistula, R. ornithinolytica was isolated from the patient's pus, and the pathogenic bacteria may originate from the gastrointestinal tract. Based on this case, We should be cautious that invasive treatment may greatly increase the probability of infection with this pathogenic bacterium.

SARS-CoV-2 NSP12 utilizes various host splicing factors for replication and splicing regulation.

The RNA-dependent RNA polymerase (RdRp) is a crucial element in the replication and transcription of RNA viruses. Although the RdRps of lethal human coronaviruses severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), SARS-CoV, and Middle East respiratory syndrome coronavirus (MERS-CoV) have been extensively studied, the molecular mechanism of the catalytic subunit NSP12, which is involved in pathogenesis, remains unclear. In this study, the biochemical and cell biological results demonstrate the interactions between SARS-CoV-2 NSP12 and seven host proteins, including three splicing factors (SLU7, PPIL3, and AKAP8). The entry efficacy of SARS-CoV-2 considerably decreased when SLU7 or PPIL3 was knocked out, indicating that abnormal splicing of the host genome was responsible for this occurrence. Furthermore, the polymerase activity and stability of SARS-CoV-2 RdRp were affected by the three splicing factors to varying degrees. In addition, NSP12 and its homologues from SARS-CoV and MERS-CoV suppressed the alternative splicing of cellular genes, which were influenced by the three splicing factors. Overall, our research illustrates that SARS-CoV-2 NSP12 can engage with various splicing factors, thereby impacting virus entry, replication, and gene splicing. This not only improves our understanding of how viruses cause diseases but also lays the foundation for the development of antiviral therapies.

Effects of Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans on Modeling Subgingival Microbiome and Impairment of Oral Epithelial Barrier.

Periodontitis is an exemplar of dysbiosis associated with the coordinated action of multiple members within the microbial consortium. The polymicrobial synergy and dysbiosis hypothesis proposes a dynamic host-microbiome balance, with certain modulators capable of disrupting eubiosis and driving shifts towards dysbiosis within the community. However, these factors remain to be explored. We established a Porphyromonas gingivalis- or Aggregatibacter actinomycetemcomitans-modified subgingival microbiome model and 16S rRNA sequencing revealed that P. gingivalis and A. actinomycetemcomitans altered the microbiome structure and composition indicated by α and ß diversity metrics. P. gingivalis increased the subgingival dysbiosis index (SDI), while A. actinomycetemcomitans resulted in a lower SDI. Furthermore, P. gingivalis-stimulated microbiomes compromised epithelium function and reduced expression of tight junction proteins, whereas A. actinomycetemcomitans yielded mild effects. In conclusion, by inoculating P. gingivalis, we created dysbiotic microcosm biofilms in vitro resembling periodontitis-related subgingival microbiota, exhibiting enhanced dysbiosis and impaired epithelium integrity.

Case report: nanopore targeted sequencing in the diagnosis of invasive pulmonary Aspergillus infection in a patient with acute promyelocytic leukemia.

Invasive pulmonary aspergillosis (IPA) is an infectious disease with a high mortality rate due to diagnostic difficulties associated with the lack of a typical clinical presentation and the inadequacy of the available laboratory testing methods. Nanopore targeted sequencing (NTS) is an alternative method of broad-based pathogen discovery, associated with rapid turnaround and high accuracy. This case report presents a patient with IPA and acute promyelocytic leukemia, diagnosed using the NTS method, which detected Aspergillus flavus in the patient's blood and pleural fluid. The patient was treated effectively with antifungal therapy. Early diagnosis of IPA improved long-term patient prognosis and quality of life.

(-)-Epicatechin gallate blocked cellular foam formation in atherosclerosis by modulating CD36 expression in vitro and in vivo.

Green tea is popular worldwide, so its main active ingredients have attracted people's attention. (-)-Epicatechin gallate (ECG) is the main active component of green tea polyphenols, which has good antioxidant activity, but its cardiovascular intervention is unknown. This study established in vitro and in vivo models of ox-LDL-induced macrophages and HFD-induced ApoE-/- mice to study the effects of ECG on atherosclerotic lesions. Firstly, the study confirmed that ECG has a therapeutic effect in different stages of atherosclerotic plaques. Subsequently, the results showed that the ox-LDL-induced release of pro-inflammatory mediators and the expression of the related protein CD86 in macrophages were inhibited by ECG. ECG blocked the formation of cellular foam by downregulating the expression of CD36 and LOX-1 proteins, thereby increasing SOD activity and reducing MDA production in cells. ECG also prevented ox-LDL-induced apoptosis, promoted macrophage migration, and increased plaque stability. The results confirmed that ECG attenuated ox-LDL-induced green fluorescence of ROS in macrophages by inhibiting the expression of related proteins in the NF-κB signaling pathway and activating the HO-1/Nrf2 signaling pathway. These results indicated that ECG has anti-oxidative stress and anti-inflammatory potential, and its molecular mechanism may be related to the inhibition of intracellular NF-κB signaling pathway proteins and activation of the HO-1/Nrf2 signaling pathway.

Panlongqi tablet suppresses adjuvant-induced rheumatoid arthritis by inhibiting the inflammatory reponse in vivo and in vitro.

ETHNOPHARMACOLOGICAL RELEVANCE: Panlongqi Tablet is prepared with the ancestral secret recipe provided by Mr. Wang Jiacheng, a famous specialist in orthopedics and traumatology of China. The efficacy and safety of PLQT have been supported by years of clinical practice in the treatment of joint-related conditions. Has remarkable effect for treating rheumatoid arthritis (RA) clinically. However, its mechanism is not entirely clear. AIM OF THE STUDY: We aim to evaluate the anti-inflammatory activity of PLQT and explore its mechanism in adjuvant-induced arthritis (AA) mice and LPS-induced Human fibroblast-like synovial (HFLS) cells. MATERIALS AND METHODS: To this end, we analyzed the active ingredients in PLQT by HPLC-MS/MS. Furthermore, the anti-RA effect of PLQT was studied through proliferation, apoptosis, foot swelling, cytokine levels, immune organ index, histopathology and related signal pathways in LPS-induced HFLS cells and AA-treated mice. RESULTS: HPLC-MS/MS results showed that PLQT contained a variety of active compounds, such as epicatechin, imperatorin, hydroxysafflor yellow A and so on. PLQT significantly inhibited the abnormal proliferation of HFLS cells induced by LPS, promoted cell apoptosis. In AA-treated mice, PLQT alleviated RA symptoms by alleviating paw swelling, synovial hyperplasia, pannus formation, inflammatory cell infiltration, and inhibiting abnormal immune responses. The results showed that PLQT significantly decreased the expression of inflammatory mediators (IL-1ß, IL-6, IL-17) in vivo and in vitro, which may be related to the regulation of PI3K/Akt, MAPK and JAK/STAT signaling pathways. CONCLUSION: Based on serum pharmacology and in vivo pharmacology studies, PLQT may regulate RA symptoms by regulating inflammatory and immune response-related pathways, which is an effective method for the treatment of RA.

Immunoenhancement activity of Bletilla striata polysaccharide through MAPK and NF-κB signalling pathways in vivo and in vitro.

Bletilla striata (Thunb.) Reichb.f., is a traditional Chinese medicine, and the Bletilla striata polysaccharide (BSP) is one of the principal components extracted from Bletilla striata with various biological activities. Previous studies have shown that many natural polysaccharides have significant immunomodulatory activities. However, as a plant polysaccharide, the research of BSP on immunomodulatory activities is limited. In this study, we aim to investigate the immunomodulatory effect of BSP in vivo and further explore its underlying mechanism in vitro. In vivo, a cyclophosphamide (CTX)-induced immunosuppression mice mode was established by intraperitoneal injection of CTX, and the immune-enhancing effect of BSP (25, 50 and 100 mg/kg) on immunosuppressed mice were evaluated. The result indicated that BSP could significantly improve the immune organ index and the content of immunoglobulin, TNF-α and IL-4 in serum. It was also found that BSP could clearly ameliorate the spleen damage induced by CTX. Meanwhile, the result showed that BSP could not only improve the proliferation of splenocytes, but also activate the lactate dehydrogenase (LDH) and acid phosphatase (ACP) in mouse spleen tissue. In vitro, potential mechanism was further revealed in macrophages. The result supported that BSP could activate macrophages with high phagocytic ability, and induce macrophages to secrete cytokines. Finally, it revealed that activation of NF-κB and MAPK signalling pathway should be the underlying mechanism of the immunoenhancment of BSP.

Tectoridin exhibits anti-rheumatoid arthritis activity through the inhibition of the inflammatory response and the MAPK pathway in vivo and in vitro.

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by inflammation infiltration of the synovial tissues and the fibroblast-like synoviocytes. Tectoridin is a botanical active ingredient with anti-inflammatory properties. In this study, the anti-arthritic effects of tectoridin and its mechanism of action are examined in TNF-α-induced human fibroblast-like synovial cells (HFLSs cells) and complete Freund's adjuvant (CFA)-stimulated arthritic mice. Arthritis progression was evaluated via bodyweight, hind paw swelling, organ index, and synovial pathology. IL-1ß, IL-6 and other pro-inflammatory factors concentrations, and the expression of MAPK pathway proteins in HFLSs cells and arthritic mice were measured using ELISA and western blotting. Results showed that tectoridin significantly decreased the swelling of the paws and joints as well as the increased immune organ index within CFA-induced arthritic mice. Histopathological analysis showed that tectoridin alleviated the lesions of ankle joints and synovial tissues induced by CFA. Secretion of pro-inflammatory cytokines in TNF-α-induced HFLSs cells and CFA-stimulated arthritic mice were also abated by tectoridin. Similarly, the presence of tectoridin significantly inhibited the abnormal phosphorylation levels of ERK, JNK, and p38 in vivo and in vitro. All those results highlighted that tectoridin exhibits anti-arthritis effects by inhibiting MAPK-mediated inflammatory responses.

Tectoridin alleviates lipopolysaccharide-induced inflammation via inhibiting TLR4-NF-κB/NLRP3 signaling in vivo and in vitro.

BACKGROUND: Tectoridin, widely extracted and separated from the rhizome of Iris tectorum Maxim, is extensively reported to have affluent bioactivity, but rarely reported to have anti-inflammatory effects. In this study, we aim to investigate the anti-inflammatory effects and the underlying mechanisms of tectoridin. METHODS: Here, RAW264.7 macrophages were stimulated with Lipopolysaccharide (LPS) for the inflammation model in vitro. Experimental animals received tectoridin and Dexamethasone (DEX) before LPS injection for endotoxic shock mouse model in vivo. The pro-inflammatory mediators and cytokines in the cell supernatant and serum were detected by ELISA kits. The tissue damages were assessed by biochemical indexes and H&E staining. Immunohistochemistry and Western blot were performed for the detection of proteins. RESULTS: Our data showed that tectoridin attenuated the LPS-up-regulated nitric oxide (NO), interleukin-6 (IL-6), and interleukin-18 (IL-18) from macrophages and tumor necrosis factor-α (TNF-α); (IL-6) and (IL-1ß) in the serum levels. Besides, our histopathological study showed that the damages caused by LPS in the lung, liver, and kidney tissues were decreased. Furthermore, our results demonstrated that tectoridin inhibited the activation of TLR4-NF-κB/NLRP3 signaling proved by immunohistochemistry assay and Western blot. CONCLUSION: Taken all together, tectoridin might have the potential ability of anti-inflammatory effects and the possible mechanism may be relevant to its inhibition of TLR4-NF-κB/NLRP3 signaling.

Tectoridin ameliorates proliferation and inflammation in TNF-α-induced HFLS-RA cells via suppressing the TLR4/NLRP3/NF-κB signaling pathway.

Tectoridin, isolated from the dry rhizome of iris, is a compound with multiple biological activities. However, its biological roles in rheumatoid arthritis (RA) have still not been clearly elucidated. The aim of this study was to focus on the effects of tectoridin on tumor necrosis factor (TNF)-α-induced human fibroblast­like synoviocyte rheumatoid arthritis (HFLS­RA) cells, and its associated mechanisms. After TNF-α stimulation, CCK8 and MTT assays, TUNEL assay and flow cytometry, Western blotting and immunohistochemistry analysis were performed to check the cell proliferation, cell apoptosis and cycle analysis, and the expression of related proteins, respectively. Our results showed that tectoridin significantly hindered cell proliferation, S-to-G2/M phase transition and down-regulated Cyclind 1 and PCNA protein levels. Additionally, tectoridin markedly promoted apoptosis rates of HFSL-RA cells and elevated the expression levels of Cleaved Caspase-3 and Bax, while reduced the expression level of Bcl-2. Moreover, tectoridin reversed TNF-α-induced overexpression of MMPs and factors associated with the TLR4/NLRP3/NF-κB pathway. We conclude that tectoridin ameliorated TNF-α-induced proliferation and inflammation by inhibiting TLR4/NLRP3/NF-κB pathway. It might provide a new insight for the clinical application of RA.

Schisandrin improves lipopolysaccharide-induced acute lung injury by inhibiting the inflammatory response in vivo and in vitro.

Acute lung injury (ALI) is characterized by an excessive inflammatory response, closely related to sepsis occurrence and development. It has been reported that Schisandrin (Sch) exhibits anti-inflammatory activity. However, whether the beneficial effects of Sch exists during ALI remains to be studied. In this study, the impact of Sch was evaluated by studying lung tissue damage, measuring the concentrations of pro-inflammatory factors, and the expression of apoptotic proteins in the LPS-induced ALI mice model. Protein expression of inflammation-related signaling pathway within the lung tissue and A549 cells were also measured. In addition, the effect of Sch on A549 cell apoptosis and inflammatory markers was also detected. Animal experiments demonstrated that pre-feeding Sch alleviated the production of inflammation mediators, abnormal pathological injuries, and blocked the progression of apoptotic events in the lung tissue. The in vitro experiments showed that Sch pretreatment reduced LPS upregulated interleukin-1ß (IL-1ß), IL-18, and IL-6 levels, and improved LPS-induced abnormal apoptosis. Sch and the pathway inhibitor AG490 also inhibited the expression levels of p-JAK2 and p-STAT3 in A549 cells. Moreover, pretreatment with Sch significantly inhibited the activation of NLRP3 inflammasomes, reduced inducible nitric oxide synthase, and cyclooxygenase 2 proteins expression during ALI in vitro and in vivo. Overall, Sch effectively alleviated ALI and provided a new mechanism to support the protective effect of Sch for sepsis-induced ALI. PRACTICAL IMPLICATIONS: ALI is characterized by inflammatory injury of the lungs, which is an important cause of high morbidity and mortality in severe patients. Sch is considered as a botanical active ingredient with various pharmacological activities, such as neuroprotective and vascular protective effects. However, the effect of Sch on ALI and its mechanism remains largely unknown. Research data indicate that Sch exerts an anti-inflammatory effect by reducing the production of inflammatory factors and abnormal apoptosis of cells, further alleviating lung damage. The protective effect of Sch was associated with inhibition of the activation of NLRP3 and the JAK2/STAT3 inflammatory pathways. The study, therefore, confirmed that Sch has a potential as an effective drug to prevent ALI diseases.

Periodontal Bifunctional Biomaterials: Progress and Perspectives.

Periodontitis is a chronic infectious disease that destroys periodontal supportive tissues and eventually causes tooth loss. It is attributed to microbial and immune factors. The goal of periodontal therapy is to achieve complete alveolar bone regeneration while keeping inflammation well-controlled. To reach this goal, many single or composite biomaterials that produce antibacterial and osteogenic effects on periodontal tissues have been developed, which are called bifunctional biomaterials. In this review, we summarize recent progress in periodontal bifunctional biomaterials including bioactive agents, guided tissue regeneration/guided bone regeneration (GTR/GBR) membranes, tissue engineering scaffolds and drug delivery systems and provide novel perspectives. In conclusion, composite biomaterials have been greatly developed and they should be chosen with care due to the risk of selection bias and the lack of evaluation of the validity of the included studies.

(-)-Epicatechin gallate blocks the development of atherosclerosis by regulating oxidative stress in vivo and in vitro.

(-)-Epicatechin gallate (ECG), as a compound in green tea extract polyphenols, has specific therapeutic effects against oxidative stress. Oxidative stress exists throughout the pathological development of atherosclerosis. In this study, two atherosclerosis models, oxidized low-density lipoprotein (ox-LDL)-induced vascular smooth muscle cells (VSMCs) and high fat diet (HFD)-induced ApoE-/- mice, were applied to explore the mechanism of ECG intervention on AS. In vivo and in vitro studies showed that ECG reduced the level of MDA and increased the activity of SOD, which are oxidative stress factors. ECG also improved HFD-induced disorder of lipid factor expression in the serum of ApoE-/- mice and alleviated oxidative stress by enhancing the antioxidant activity. The potential mechanism was supposed to be the inhibition of the phosphorylation of p65 by ECG in the NF-κB pathway in the aorta, thereby blocking the expression of inflammatory mediators. In addition, ECG increased the stability of atherosclerosis plaques by reducing the expression of MMP-2 and ICAM-1 in atherosclerosis diseased tissues. ECG reduced lipid accumulation in the aorta and its roots and also plaque neoplasia. Western blotting experiments indicated that ECG increased the nuclear transfer of Nrf2 and the expression of heme oxygenase 1 (HO-1) was increased. These results demonstrated that ECG significantly reduced the formation of aortic plaque in ApoE-/- mice which was possibly triggered by the inhibition of hyperlipidemia and oxidative stress that exhibited the anti-atherosclerotic potential.

Quyu Shengxin capsule (QSC) inhibits Ang-II-induced abnormal proliferation of VSMCs by down-regulating TGF-ß, VEGF, mTOR and JAK-STAT pathways.

ETHNOPHARMACOLOGICAL RELEVANCE: Quyu Shengxin capsule (QSC) is an herbal compound commonly used to treat blood stasis syndrome in China, and blood stasis syndrome is considered to be the root of cardiovascular diseases (CVD) in traditional Chinese medicine. However, the potential molecular mechanism of QSC is still unknown. AIM OF STUDY: To study the therapeutic effect of QSC on the abnormal proliferation of VSMCs induced by Ang-II, and to explore its possible mechanism of action. MATERIALS AND METHODS: Qualitative analysis and quality control of QSC through UPLC-MS/MS and UPLC. The rat thoracic aorta vascular smooth muscle cells (VSMCs) were cultured in vitro, and then stimulated with Angiotensin Ⅱ (Ang-II) (10-7 mol/L) for 24 h to establish a cardiovascular cell model. The cells were then treated with different concentrations of QSC drug-containing serum or normal goat serum. MTT assay was used to detect the viability of VSMCs and abnormal cell proliferation. In order to analyze the possible signal transduction pathways, the content of various factors in the supernatant of VSMCs was screened and determined by means of the Luminex liquid suspension chip detection platform, and the phosphoprotein profile in VSMCs was screened by Phospho Explorer antibody array. RESULTS: Compared with the model group, serum cell viability and inflammatory factor levels with QSC were significantly decreased (P < 0.001). In addition, the expression levels of TGF-ß, VEGF, mTOR and JAK-STAT in the QSC-containing serum treatment group were significantly lower than those in the model group. QSC may regulate the pathological process of CVD by reducing the levels of inflammatory mediators and cytokines, and protecting VSMCs from the abnormal proliferation induced by Ang-II. CONCLUSION: QSC inhibits Ang-II-induced abnormal proliferation of VSMCs, which is related to the down-regulation of TGF-ß, VEGF, mTOR and JAK-STAT pathways.

Imperatorin reduces the inflammatory response of atherosclerosis by regulating MAPKs signaling pathway in vivo and in vitro.

Inflammation plays an important role in the process of atherosclerosis (AS). Inhibition of inflammation is an effective way to prevent AS. Imperatorin (IMP) is a kind of furan coumarin with various activities. In this study, the anti-inflammatory effect of IMP was explored in oxidized low-density lipoprotein (ox-LDL)-induced VSMCs and high fat diet (HFD)-induced ApoE-/- mice. The results showed that IMP attenuated the elevation of TNF-α, IL-6, MCP-1 and NO induced by ox-LDL in supernatant of VSMCs. IMP has normalized the levels of serum lipids (TC, TG, LDL-C and HDL-C) and attenuated inflammatory cytokines in serum. IMP also improved pathological changes and lipid accumulation in aorta. Matrix metalloproteinase-2 (MMP-2) expression in aorta was down-regulated by IMP. IMP could inhibit the phosphorylation of MAPKs pathway in the aorta and VSMCs, resulting in a significant decrease in the contents of p-ERK 1/2, p-JNK and p-P38. Overall, IMP could exert anti-inflammatory effects in vivo and in vitro to interfere with AS.

Enhancing cellulosic ethanol production through coevolution of multiple enzymatic characteristics of ß-glucosidase from Penicillium oxalicum 16.

In previous studies, we isolated a novel ß-glucosidase from Penicillium oxalicum 16 (16BGL), which is useful for producing cellulosic ethanol. However, 16BGL has a relatively low enzyme activity and product tolerance; besides, a huge gap exists between the optimum temperature of 16BGL (70 °C) and the fermentation temperature for producing cellulosic ethanol (40 °C). Here, we present a directed evolution-based study, which combines one-round error-prone PCR with three rounds of high-throughput screening, for coevolving multiple enzymatic characteristics of 16BGL. We identified an improved variant Y-1-B1 with a triple mutant (G414S/D421V/T441S). Y-1-B1 had an optimum temperature of 50 °C, much closer to the fermentation temperature. The catalytic efficiency of Y-1-B1 for hydrolyzing pNPG was 1355 mM-1 s-1 at 50 °C and pH 5, significantly higher than that of 16BGL (807 mM-1 s-1). Y-1-B1 also achieved a slightly reduced strength of product inhibition of 1.1 at a glucose concentration of 20 mM, compared with the ratio of 1.3 for 16BGL. A maximum titer of 6.9 g/L for ethanol production was achieved in the reaction with Y-1-B1, which was 22% higher than that achieved with 16BGL. Structure modeling revealed that the mutations are distant from the active-site pocket. Therefore, we performed molecular dynamics (MD) simulations to understand why these mutations can improve catalytic efficiency. MD simulation revealed that the nucleophilic residue Asp261 had a much closer contact with the glucosidic center of pNPG in the simulation with Y-1-B1 than that with 16BGL, suggesting that the mutant is more favorable for catalysis. KEY POINTS: • Multiple enzymatic properties of Penicillium oxalicum 16 BGL were coevolved. • A catalytically efficient triple mutant G414S/D421V/T441S was reported. • Molecular dynamics simulation supported the enhanced catalytic activity.

Co-evolution of ß-glucosidase activity and product tolerance for increasing cellulosic ethanol yield.

ß-Glucosidase (BGL) plays a key role in cellulose hydrolysis. However, it is still a great challenge to enhance product tolerance and enzyme activity of BGL simultaneously. Here, we utilized one round error-prone PCR to engineer the Penicillium oxalicum 16 BGL (16BGL) for improving the cellulosic ethanol yield. We identified a new variant (L-6C), a triple mutant (M280T/V484L/D589E), with enhanced catalytic efficiency ([Formula: see text]) for hydrolyzing pNPG and reduced strength of inhibition ([Formula: see text]) by glucose. To be specific, L-6C achieved a [Formula: see text] of 0.35 at a glucose concentration of 20 mM, which was 3.63 times lower than that attained by 16BGL. The catalytic efficiency for L-6C to hydrolyze pNPG was determined to be 983.68 mM-1 s-1, which was 22% higher than that for 16BGL. However, experiments showed that L-6C had reduced binding affinity (2.88 mM) to pNGP compared with 16BGL (1.69 mM). L-6C produced 6.15 g/L ethanol whose yield increased by about 10% than 16BGL. We performed molecular docking and molecular dynamics (MD) simulation, and binding free energy calculation using the Molecular Mechanics/Poisson Boltzmann surface area (MM/PBSA) method. MD simulation together with the MM/PBSA calculation suggested that L-6C had reduced binding free energy to pNPG, which was consistent with the experimental data.

Recombinant Penicillium oxalicum 16 ß-Glucosidase 1 Displays Comprehensive Inhibitory Resistance to Several Lignocellulose Pretreatment Products, Ethanol, and Salt.

ß-Glucosidase (BGL) is a rate-limiting enzyme of lignocellulose hydrolysis for second-generation bioethanol production, but its inhibition by lignocellulose pretreatment products, ethanol, and salt is apparent. Here, the recombinant Penicillium oxalicum 16 BGL 1 (rPO16BGL1) from Pichia pastoris GS115 kept complete activity at 0.2-1.4 mg/mL furan derivatives and phenolic compounds, 50 mg/mL sodium chloride (potassium chloride), or 100 mg/mL ethanol at 40 °C. rPO16BGL1 retained above 50% residual activity at 30 mg/mL organic acid sodium, and 60% residual activity at 40 °C with 300 mg/mL ethanol. Sodium chloride and potassium chloride had a complicated effect on rPO16BGL1, which resulted in activation or inhibition. The inhibition kinetics of the enzyme reaction demonstrated that organic acids and organic acid sodium were non-competitive inhibitors and that ethanol was a competitive inhibitor at < 1.5 mg/mL salicin. Moreover, substrate inhibition of the enzyme was found at > 2 mg/mL salicin, and the Km/KI and Km/KSI average values revealed that the inhibitory strength was ranked as salicin-organic acids > organic acids > salicin-organic acid sodium salt > organic acid sodium salt > salicin > salicin-KCl > salicin-NaCl > salicin-ethanol > ethanol.