Preparation of housefly (Musca domestica) larvae protein hydrolysates: Influence of dual-sweeping-frequency ultrasound-assisted enzymatic hydrolysis on yield, antioxidative activity, functional and structural attributes

Dual-sweeping-frequency ultrasound (DSFU) was utilized in the preparation of polypeptides from housefly (Musca domestica) larvae protein (HLP). Results indicated that ultrasonication (20 ± 2/28 ± 2 kHz, 42 W/L, 25 min) significantly increased peptide yield and DPPH scavenging capacity by 8.25 % and 14.83 %, respectively. Solubility, foaming and emulsification properties of polypeptides were improved by 19.89 %, 33.33 % and 38.74 % over the control; along with notable reduction in particle size and increase in zeta potential. Tertiary structural changes of the sonicated hydrolysates were illustrated by UV and fluorescence spectra. FTIR showed that ultrasonication increased α-helix, β-turn, and random coil by 38.23 %, 46.35 % and 16.36 %, respectively, but decreased β-sheet by 48.03 %, indicating partial unfolding in HLP hydrolysate conformation and reduction in intermolecular interactions. The research results demonstrated that dual-sweeping-frequency ultrasonication has a great prospect in industry application for the purpose of improving enzymolysis efficiency and product quality for housefly larvae protein hydrolysates production.

Effect of carbonyl-amino condensation, non-covalent cross-linking and conformational changes induced by ultrasound-assisted Maillard reaction on lysinoalanine formation in silkworm pupa protein

The inhibition of cross-linked lysinoalanine (LAL) formation in silkworm pupa protein isolates (SPPI) by Maillard reaction (using varying xylose concentration) and ultrasound treatment was studied. Results showed that sonicated SPPI was effectively grafted with high concentration of xylose (5 %), resulting in the lowest LAL content, which was 48.75 % and 30.64 % lower than the control and ultrasound-treated samples, respectively. Chemical bond analysis showed that the combined treatment destroyed the ionic bonds, intrachain (g-g-t), and interchain (g-g-g) disulfide bonds, but stimulated the polymerization of hydrogen and hydrophobic bonds between SPPI and xylose, and as well enhanced the net negative charge between SPPI/Xylose complexes. The particles of the complexes were more loose, dispersed and rough, and had a stronger hydrophilic microenvironment, accompanied by alterations in microscopic, secondary and tertiary structures. Ultrasound treatment induced the breakdown of the oxidative cross-linking in SPPI, and promoted the sulfhydryl group-dehydroalanine binding and the carbonyl-amino condensation of the protein and xylose, and thus inhibited the formation of cross-linked LAL. Furthermore, the physicochemical and structural parameters were highly interrelated with cross-linked LAL content (|r| > 0.9). The outcomes provided a novel avenue and theoretical basis for minimizing LAL formation in SPPI and improving the nutrition and safety of SPPI.

Application of Fixed Frequency Ultrasound in the Cultivation of S. cerevisiae for Rice Wine Fermentation

BACKGROUND

Rice wine fermentation is limited by its long fermentation time, weak taste, and unpleasant flavors such as oil and odor. In this study, a novel ultrasound technology of Saccharomyces cerevisiae was used with the aim of improving fermentation efficiency and volatile flavor quality of RW.

RESULTS

The results showed that fixed frequency ultrasonic treatment (28 kHz, 45 W/L, 20 min) of S. cerevisiae seed culture at its logarithmic metaphase significantly increased the biomass and alcohol yield by 31.58% and 26.45%, respectively, and reduced fermentation time by nearly 2 days. Flavor analysis indicated that the flavor compounds in RW, specifically the esters and alcohols, were also increased in quantity after the ultrasonic treatment of S. cerevisiae seed liquid. The isobutyl acetate, ethyl butyrate, ethyl hexanoate and phenethyl acetate contents were increased by 78.92, 129.19, 7.79 and 97.84%, respectively, as compared to the control.

CONCLUSION

The results show that ultrasonic treatment of S. cerevisiae reduced fermentation time and enhanced the flavor profile of RW. This study can provide the theoretical and/or technological basis for the research and development of RW. This article is protected by copyright. All rights reserved.

Effect of pectin concentration on emulsifying properties of black soldier fly (Hermetia illucens) larvae albumin modified by pH-shifting and ultrasonication

The effect of pectin concentration on the structural and emulsifying properties of black soldier fly larvae albumin (BSFLA) modified by pH-shifting (pH12) and ultrasound (US) was studied. The results (intrinsic fluorescence, surface hydrophobicity, Fourier transform infrared spectrum, and disulfide bonds) showed that modified BSFLA samples, especially pH12-US, were more likely to bind to pectin through hydrogen bonding, electrostatic interactions, and hydrophobic interactions due to the unfolding of BSFLA, the collapse of disulfide bonds and exposure of hydrophobic groups. Thus, a BSFLA-pectin complex with smaller particle size, more negative charges, and a relatively loose structure was formed. The emulsifying activity (EAI) and stability index (ESI) of pH12-US modified BSFLA were significantly enhanced by the addition of pectin, reaching the highest values (associated with 174.41 % and 643.22 % increase, respectively) at pectin concentration of 1.0 %. Furthermore, the interface modulus of the emulsion prepared by the modified BSFLA was mainly viscous, and had higher apparent viscosity, smaller particle size and droplet size, contributing to higher EAI and ESI. The study findings suggest the addition of pectin to pH12-US treated BSFLA could be used in industry to prepare BSFLA-pectin emulsion with exceptional/desirable properties.

Hexagonal plate ultrasound pretreatment on the correlation between soy protein isolate structure and cholesterol-lowering activity of peptides, and protein's enzymolysis kinetics, thermodynamics

In this study, a hexagonal plate ultrasound (HPU) pretreatment technology was employed to modify soy protein isolate (SPI) and enhance the hypocholesterolemic activity of enzymatic digests from SPI. Results demonstrated that under the condition of ultrasound power density of 40 W/L, the hypocholesterolemic activity of enzymatic digests from HPU-pretreated SPI (HPU-SPI) increased by 88.40 % compared to control group after gastrointestinal digestion. The sulfhydryl content of HPU-SPI increased by a maximum of 45.32 % compared to control group. Fourier transform infrared and scanning electron microscopy revealed that HPU pretreatment partially unfolded the SPI conformation, reduced the intermolecular interactions, and exposed the internal hydrophobic regions. Pearson correlation analysis showed that sulfhydryl groups (r = 0.860), disulfide bonds (r = -0.875) and random coil (r = 0.917) were strongly correlated with the cholesterol-lowering activity of soy protein hydrolysate (SPH), following a simulated gastrointestinal digestion. Finally, the effects of HPU pretreatment on enzymolysis kinetics and thermodynamics of the SPI enzymatic process showed that HPU pretreatment significantly reduced the Mie's constant, activation energy, activation enthalpy, activation entropy and Gibbs free energy. Overall, the study outcome suggested that HPU pretreatment could positively influence the hypocholesterolemic peptide activity, and thus, may be beneficial to the pharmaceutical/food industry.

Disrupted RNA editing in beta cells mimics early-stage type 1 diabetes

A major hypothesis for the etiology of type 1 diabetes (T1D) postulates initiation by viral infection, leading to double-stranded RNA (dsRNA)-mediated interferon response and inflammation; however, a causal virus has not been identified. Here, we use a mouse model, corroborated with human islet data, to demonstrate that endogenous dsRNA in beta cells can lead to a diabetogenic immune response, thus identifying a virus-independent mechanism for T1D initiation. We found that disruption of the RNA editing enzyme adenosine deaminases acting on RNA (ADAR) in beta cells triggers a massive interferon response, islet inflammation, and beta cell failure and destruction, with features bearing striking similarity to early-stage human T1D. Glycolysis via calcium enhances the interferon response, suggesting an actionable vicious cycle of inflammation and increased beta cell workload.

Emulsification and encapsulation properties of conjugates formed between whey protein isolate and carboxymethyl cellulose under acidic conditions

In this study, carboxymethyl cellulose (CMC) was used to interact with whey protein isolate (WPI) to prepare conjugates as emulsifiers and embedding agents, which can be used under acidic conditions. Firstly, the effects of ratios and pH values on the formation of WPI-CMC conjugates were investigated. The turbidity and particle size of WPI were reduced in the presence of CMC at pH 4.6 (near the isoelectric point). Then the characterization of physicochemical properties indicated that electrostatic interactions played a major role in the formation of WPI-CMC conjugates, thereby changing the structure and function of conjugates. CMC and WPI reached the optimal aggregation state at pH 4.6 and a ratio of 4:1. The conjugates exhibited excellent emulsifying activity and stability for the oil-in-water emulsions. WPI-CMC conjugates also could provide protection to allicin by preventing degradation under environmental stresses, while maintaining its antioxidant activity.

Inhibition of cross-linked lysinoalanine formation in pH12.5-shifted silkworm pupa protein, and functionality thereof: Effect of ultrasonication and glycation

We added three different carbohydrates (Xylose/Xyl, Maltose/Mal, and Sodium alginate/Sal) to pH12.5-shifted silkworm pupa protein isolates (SPPI), and examined the influence of multi-frequency ultrasound (US) on them, with reference to lysinoalanine (LAL) formation, changes in conformational characteristics and functionality. Results showed that, the LAL content of the glycoconjugates - SPPI-Xyl, SPPI-Mal, and SPPI-Sal decreased by 1.47, 1.39, and 1.54 times, respectively, compared with the control. Notably, ultrasonication further reduced the LAL content by 45.85 % and brought SPPI-Xyl highest graft degree (57.14 %). SPPI-Xyl and SPPI-Mal were polymerized by different non-covalent bonds, and SPPI-Sal were polymerized through ionic, hydrogen, and disulfide (covalent/non-covalent) bonds. Significant increase in turbidity, Maillard reaction products and the formation of new hydroxyl groups was detected in grafted SPPI (p < 0.05). US and glycation altered the structure and surface topography of SPPI, in which sugars with high molecular weight were more likely to aggregate with SPPI into enormous nanoparticles with high steric hindrance. Compared to control, the solubility at pH 7.0, emulsifying capacity and stability, and foaming capacity of SPPI-US-Xyl were respectively increased by 244.33 %, 86.5 %, 414.67 %, and 31.58 %. Thus, combined US and xylose-glycation could be an effective approach for minimizing LAL content and optimizing functionality of SPPI.

Risk Factors for Locoregional Recurrence and Distant Metastasis in 143 Patients with Adenoid Cystic Carcinoma of the External Auditory Canal

AIMS

Adenoid cystic carcinoma (ACC) grows slowly and is characterised by potential recurrence and metastasis to distant organs. This study aimed to evaluate the risk factors for locoregional recurrence (LRR) and distant metastasis in patients with ACC of the external auditory canal (EAC).

MATERIALS AND METHODS

Demographic, pathological, therapeutic and survival data of 143 patients with EAC ACC were reviewed in this study. Univariate and multivariate Cox proportional hazard regression analyses were carried out to determine the risk factors for LRR and distant metastasis. Factors associated with overall survival after LRR and distant metastasis were also analysed.

RESULTS

During a median follow-up of 49 months, 31 of 143 patients were observed with LRR and 34 developed distant metastasis. Bone invasion and histological subtype were independent risk factors for locoregional recurrence-free survival. T stage and LRR were independent risk factors for distant metastasis-free survival. Salvage surgery and adjuvant radiotherapy or chemoradiotherapy for LRR resulted in better survival, whereas extrapulmonary metastasis and LRR were associated with a higher risk of poor survival after distant metastasis.

CONCLUSION

Patients with distant metastases, especially those with LRR, are at significant risk of poor prognosis. Our findings emphasise the importance of long-term regular follow-up and recommend surgical intervention with radiotherapy for recurrent EAC ACC.

[Retracted] miR‑25 promotes metastasis via targeting FBXW7 in esophageal squamous cell carcinoma

Following the publication of the above paper, it was drawn to the Editor's attention by a concerned reader that a large number of data panels showing cell migration and invasion assay data in Figs. 3C and 5 contained overlapping sections, such that data that were intended to show results obtained under different experimental conditions may have been derived from a smaller number of original sources. In addition, certain of the data in this pair of figures were strikingly similar to data that were submitted for publication in another journal at around the same time as the above paper was submitted to Oncology Reports. Finally, regarding the western blotting data shown in Fig. 4B, an obvious splice in the gel strip was noticed for the FBXW7 bands, whereas no equivalent splice was present in the associated GADPH loading control, suggesting that these data originated from different gels. Owing to the fact that the contentious data in the above article were under consideration for publication at around the time that this was submitted to Oncology Reports, in addition the other features of concern regarding the data, the Editor has decided that this paper should be retracted from the Journal on account of a lack of confidence in the presented data. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive a reply. The Editor apologizes to the readership for any inconvenience caused. [Oncology Reports 38: 3030‑3038, 2017; DOI: 10.3892/or.2017.5995].

Modification of whey protein isolate by ultrasound-assisted pH shift for complexation with carboxymethylcellulose: Structure and interfacial properties

The application of whey protein isolate (WPI) is limited because of its compact spherical structure. In this study, ultrasound-assisted pH shift was employed to modify WPI for complexation with carboxymethylcellulose (CMC). The foaming and emulsifying properties of WPI/CMC complexes were investigated. The results demonstrate that the pretreatment of ultrasound-assisted pH 12 shift increased the content of free sulfhydryl groups from 16.5 μmol/g to 34.7 μmol/g and enhanced protein hydrophobicity from 311.4 to 370.6 (p < 0.05). Compared to the complexes formed by untreated WPI and CMC, the complexes pretreated with ultrasound-assisted pH 12 shift had a smaller size of 293.4 nm and a more uniform distribution. Furthermore, WPI/CMC complexes pretreated by ultrasound-assisted pH 12 shift exhibited higher emulsifying activity and emulsion stability index, which were increased by 8.9 % and 42.6 % respectively, in comparison with the control group (p < 0.05). A positive correlation was found between the surface hydrophobicity of WPI and emulsifying activity of WPI/CMC complexes. Ultrasound-assisted pH 2 shift improved the foaming capacity of complexes by 28.3 % over the control (p < 0.05). All the results indicate that the interfacial properties of WPI/CMC complexes can be improved significantly by the combination of pH shift and ultrasound.

Genetic risk converges on regulatory networks mediating early type 2 diabetes

Type 2 diabetes mellitus (T2D), a major cause of worldwide morbidity and mortality, is characterized by dysfunction of insulin-producing pancreatic islet β cells1,2. T2D genome-wide association studies (GWAS) have identified hundreds of signals in non-coding and β cell regulatory genomic regions, but deciphering their biological mechanisms remains challenging3-5. Here, to identify early disease-driving events, we performed traditional and multiplexed pancreatic tissue imaging, sorted-islet cell transcriptomics and islet functional analysis of early-stage T2D and control donors. By integrating diverse modalities, we show that early-stage T2D is characterized by β cell-intrinsic defects that can be proportioned into gene regulatory modules with enrichment in signals of genetic risk. After identifying the β cell hub gene and transcription factor RFX6 within one such module, we demonstrated multiple layers of genetic risk that converge on an RFX6-mediated network to reduce insulin secretion by β cells. RFX6 perturbation in primary human islet cells alters β cell chromatin architecture at regions enriched for T2D GWAS signals, and population-scale genetic analyses causally link genetically predicted reduced RFX6 expression with increased T2D risk. Understanding the molecular mechanisms of complex, systemic diseases necessitates integration of signals from multiple molecules, cells, organs and individuals, and thus we anticipate that this approach will be a useful template to identify and validate key regulatory networks and master hub genes for other diseases or traits using GWAS data.

Nimotuzumab plus concurrent chemo-radiotherapy in unresectable locally advanced oesophageal squamous cell carcinoma (ESCC): interim analysis from a Phase 3 clinical trial

BACKGROUND

This prospectively randomised, double-blinded, placebo-controlled, multicenter Phase 3 clinical trial was conducted to assess the efficacy and safety profile of nimotuzumab (nimo) plus concurrent chemo-radiotherapy (CCRT) in patients with unresectable locally advanced ESCC.

METHODS

Patients were randomly assigned (1:1) to receive CCRT plus nimotuzumab or placebo. The primary endpoint was overall survival (OS). In addition, interim analysis for short-term response rate was pre-defined.

RESULTS

A total of 201 patients were randomised into two groups. Eighty patients in the nimo group and eighty-two in the placebo group were evaluable. Three to six months after treatment, 26 (32.5%) patients achieved complete response (CR) in the nimo group, and 10 (12.2%) in the placebo group (P = 0.002). The ORR of the nimo group was significantly higher than the placebo group (93.8% vs. 72.0%, P < 0.001). The two groups' grade 3-5 adverse drug reactions were 11.1% vs. 10.9% (P > 0.05).

CONCLUSIONS

Nimotuzumab, in combination with chemo-radiotherapy, increased the CRR and ORR with a good safety profile. The OS is needed to be followed and finally analysed.

CLINICAL TRIAL REGISTRATION

NCT02409186.

Enhancing the growth of thermophilic Bacillus licheniformis YYC4 by low-intensity fixed-frequency continuous ultrasound

The effect of low-intensity fixed-frequency continuous ultrasound (LIFFCU) on the growth of Bacillus licheniformis YYC4 was investigated. The changes in morphology and activity of the organism, contributing to the growth were also explored. Compared with the control, a significant increase (48.95%) in the biomass of B. licheniformis YYC4 (at the logarithmic metaphase) was observed following the LIFFCU (28 kHz, 1.5 h and 120 W (equivalent to power density of 40 W/L)) treatment. SEM images showed that ultrasonication caused sonoporation, resulting in increased membrane permeability, evidenced by increase in cellular membrane potential, electrical conductivity of the culture, extracellular protein and nucleic acid, and intracellular Ca2+ content. Furthermore, LIFFCU action remarkably increased the extracellular protease activity, volatile components of the culture medium, microbial metabolic activity, and spore germination of the strain. Therefore, LIFFCU could be used to efficiently promote the growth of targeted microorganisms.

Pancreatic islet α cell function and proliferation requires the arginine transporter SLC7A2

Interrupting glucagon signaling decreases gluconeogenesis and the fractional extraction of amino acids by liver from blood resulting in lower glycemia. The resulting hyperaminoacidemia stimulates α cell proliferation and glucagon secretion via a liver-α cell axis. We hypothesized that α cells detect and respond to circulating amino acids levels via a unique amino acid transporter repertoire. We found that Slc7a2ISLC7A2 is the most highly expressed cationic amino acid transporter in α cells with its expression being three-fold greater in α than β cells in both mouse and human. Employing cell culture, zebrafish, and knockout mouse models, we found that the cationic amino acid arginine and SLC7A2 are required for α cell proliferation in response to interrupted glucagon signaling. Ex vivo and in vivo assessment of islet function in Slc7a2-/- mice showed decreased arginine-stimulated glucagon and insulin secretion. We found that arginine activation of mTOR signaling and induction of the glutamine transporter SLC38A5 was dependent on SLC7A2, showing that both's role in α cell proliferation is dependent on arginine transport and SLC7A2. Finally, we identified single nucleotide polymorphisms in SLC7A2 associated with HbA1c. Together, these data indicate a central role for SLC7A2 in amino acid-stimulated α cell proliferation and islet hormone secretion.

[Correction model of the sampling time error on the blood trough concentration of tacrolimus in non-sustained-release dosage form for renal transplant recipients]

Objective: To establish correction model of the sampling time error on the blood trough concentration of tacrolimus in non-sustained-release dosage form for renal transplant recipient and improve the accuracy of drug dose assessment and clinical adjustment in renal transplant recipients. Methods: Visit records of 206 outpatients in the Department of Transplantation, Nanfang Hospital, Southern Medical University were retrospectively collected from October 15, 2022 to October 30, 2022. The distribution of sampling time of tacrolimus blood drug concentration was described and the time range of correction was determined. Twenty inpatients after renal transplantation in the Department of Transplantation, Nanfang Hospital, Southern Medical University from October 1, 2022 to November 30, 2022 were prospectively included, and their demography data, laboratory test results during follow-ups, and CYP3A5 genotype were collected. The patients took tacrolimus in non-sustained-release dosage form every 12 h starting from 19∶30 on the day of admission. Peripheral blood samples were collected from the patients on the second day of admission at 7∶30 and on the third day at 6∶00-10∶00 every 30 minutes to test the blood concentration of tacrolimus. Using the collection time as the independent variable and the blood tacrolimus concentration as the dependent variable, a simple linear regression was performed to fitting a linear model of tacrolimus blood concentration-sampling time. Multiple linear regression was performed to analyze the influencing factors of the tacrolimus metabolic rate within a specific period and generate the regression equation. Results: The 206 outpatients aged (46±13) years, including 131 males (63.6%). The time gap [M (Q₁, Q₃)] between the sampling time of the follow-up outpatients and standard C₁₂ was 24 (13.0, 46.5) min, and the maximum time gap was 135 min. The 20 enrolled inpatients aged (45±12) years, including 15 males (75.0%). There was no significant difference in the blood concentration of tacrolimus collected at 7∶30 on the second (7.87±2.21)ng/ml and third days (7.84±2.33)ng/ml after admission of the enrolled inpatients (P=0.917), and the blood tacrolimus concentration rhythm was stable in the trial. The plasma concentration of C_10.5-C_14.5 was linearly related to the time, with R² [M (Q₁, Q₃)] 0.88 (0.85, 0.92) and all P<0.05. The metabolic rate of tacrolimus during C_10.5-C_14.5=0.984+0.090×basic concentration of tacrolimus (ng/ml)-0.036×body mass index+0.489×CYP3A5 genotype-0.007×hemolobin(g/L)-0.035×alanine aminotransferase (U/L)+0.143×total cholesterol (mmol/L)+0.027×total bilirubin (μmol/L), with R²=0.85. Conclusion: This study propose a correction model for tacrolimus (non-sustained-release dosage form) trough concentration around C₁₂, which is helpful for clinicians to easily and accurately assess renal transplant recipients' tacrolimus exposure.

Synergistic effects of pH shift and heat treatment on solubility, physicochemical and structural properties, and lysinoalanine formation in silkworm pupa protein isolates

The application of silkworm pupa protein isolates (SPPI) in food industry was limited because SPPI's solubility is poor and it contains a potential harmful component of lysinoalanine (LAL) which formed during protein extraction. In this study, combined treatments of pH shift and heating were performed to improve the solubility of SPPI and to reduce the content of LAL. The experimental results showed that the promoting effect on SPPI's solubility by alkaline pH shift + heat treatment was greater than that by acidic pH shift + heat. And an 8.62 times increase of solubility was observed after pH 12.5 + 80 ℃ treatment compared to the control SPPI sample which was extracted at pH 9.0 without pH shift treatment. Very strong positive correlation was found between alkali dosage and SPPI solubility (Pearson's correlation coefficient r = 0.938). SPPI with pH 12.5 shift treatment showed the highest thermal stability. Alkaline pH shift combined with heat treatment altered the micromorphology of SPPI and destroyed the disulfide bonds between macromolecular subunits (72 and 95 kDa), resulting in reduced particle size and increased zeta potential and free sulfhydryl content of the isolates. The fluorescence spectra analysis showed red shifts phenomena with pH increasing and fluorescence intensity increase with temperature increasing, implying the alterations in the tertiary structure of protein. Compared to the control SPPI sample, the amount of LAL reduced by 47.40 %, 50.36 % and 52.39 % using pH 12.5 + 70 ℃, pH 12.5 + 80 ℃ and pH 12.5 + 90 ℃ treatment, respectively. These findings provide fundamental information for the development and application of SPPI in food industry.

Differential Expression of Autophagy-Related Long Non-Coding RNA in Melanoma

To explore the role of autophagy-related differential long non-coding RNA (lncRNA) in the pathogenesis of melanoma, we established a prognostic prediction model for patients with melanoma based on the expression profiles of autophagy-related gene. Based on The Cancer Genome Atlas and GeneCard database, we used single-sample gene set enrichment analysis (ssGSEA), weighted gene co-expression network analysis (WGCNA), uniCOX in R software for COX proportional hazard regression analysis, and enrichment analysis to get an idea of biological processes with autophagy-related genes, which evaluates the relationship between autophagy-related genes and immune cell infiltration in patients with melanoma. The roles of identified lncRNA were evaluated by the risk score based on the results of single factor regression analysis for each lncRNA and on the prognosis for patients obtained from the database. Then, the whole sample was divided into high- and low-risk groups. Survival curve analysis showed that low-risk group had a better prognosis. Enrichment analysis revealed multiple key pathways enriched with lncRNA-associated genes. Analysis of immune cell infiltration revealed differences between high- and low-risk groups. Finally, 3 datasets verified the effect of our model on prognosis. There are important autophagy-related lncRNA in patients with melanoma. Top 6 lncRNA are significantly related to the overall survival rate of patients with melanoma and provide the basis for predicting the prognostic survival of patients.

Mixed-Strain Fermentation Conditions Screening of Polypeptides from Rapeseed Meal and the Microbial Diversity Analysis by High-Throughput Sequencing

Conventional fermentation of rapeseed meal has disadvantages such as sterilization requirement, high energy consumption and low efficiency, as well as poor action of single bacteria. To overcome these drawbacks, mixed-strain fermentation of unsterilized rapeseed meal was investigated. Mixed-fermentation of unsterilized rapeseed meal (ratio of solid–liquid 1:1.2 g/mL) using Bacillus subtilis, Pediococcus acidilactici and Candida tropicalis (at 40 °C, for 3 days, with inoculation amount of 15% (w/w)) substantially increased the polypeptide content in rapeseed meal by 814.5% and decreased the glucosinolate content by 46.20%. The relationship between microbial diversity and physicochemical indicators showed that the improvement in polypeptide content was mainly caused by C. tropicalis (on the first day of fermentation) and B. subtilis (on the second day). Compared to raw rapeseed meal, the microbial diversity following the fermentation was significantly reduced, indicating that mixed-strain fermentation can inhibit the growth of miscellaneous bacteria. The study findings suggest that mixed-strain fermentation could be used to considerably increase the polypeptide content of unsterilized rapeseed meal, increasing the potential of rapeseed meal.

Recent Insight on Edible Insect Protein: Extraction, Functional Properties, Allergenicity, Bioactivity, and Applications

Due to the recent increase in the human population and the associated shortage of protein resources, it is necessary to find new, sustainable, and natural protein resources from invertebrates (such as insects) and underutilized plants. In most cases, compared to plants (e.g., grains and legumes) and animals (e.g., fish, beef, chicken, lamb, and pork), insect proteins are high in quality in terms of their nutritional value, total protein content, and essential amino acid composition. This review evaluates the recent state of insects as an alternative protein source from production to application; more specifically, it introduces in detail the latest advances in the protein extraction process. As an alternative source of protein in food formulations, the functional characteristics of edible insect protein are comprehensively presented, and the risk of allergy associated with insect protein is also discussed. The biological activity of protein hydrolyzates from different species of insects (Bombyx mori, Hermetia illucens, Acheta domesticus, Tenebrio molitor) are also reviewed, and the hydrolysates (bioactive peptides) are found to have either antihypertensive, antioxidant, antidiabetic, and antimicrobial activity. Finally, the use of edible insect protein in various food applications is presented.

The structure, antioxidant and antibacterial properties of thiol-modified soy protein isolate induced by allicin

This study investigated the effect of allicin binding on the structure, antioxidant and antibacterial properties of soy protein isolate (SPI). Results showed that allicin bound to 82.6 % free thiol groups of SPI at a molar ratio of 0.5. The combination of allicin and SPI significantly affected the structure of protein. Result of circular dichroism showed that the content of α-helix decreased by 26.9 % and the content of β-sheet increased by 12.2 % over control when the molar ratio was 0.5. The result of surface hydrophobicity signified the unfolding of SPI with the action of allicin. These results implied that allicin binding might be a suitable method for the modification of SPI. Furthermore, the antibacterialand antioxidant experiments indicated that allicin-SPI conjugates not only had the capacity to inhibit the growth of Escherichia coli and Staphyloccocus aureus, but also had DPPH and ABTS radicals scavenging activities.

Nimotuzumab plus concurrent chemo-radiotherapy versus chemo-radiotherapy in unresectable locally advanced esophageal squamous cell carcinoma (ESCC): Interim analysis from a prospective, randomized-controlled, double-blinded, multicenter, and phase III clinical trial (NXCEL1311 Study)

4016

Background: 70% of esophageal carcinoma are unresectable at diagnosis. Despite active clinical research on the treatment of esophageal squamous cell carcinoma (ESCC), the long-term survival rate of advanced patients is still very low, with a 5-year survival rate of 30%-40%. A prospective, randomized-controlled, double-blinded, multicenter, and phase III study (NXCEL1311) was designed to investigate the efficacy and safety of nimotuzumab (anti-EGFR humanized monoclonal antibody;abbreviate,Nimo) plus concurrent chemo-radiotherapy compared with placebo plus chemo-radiotherapy in unresectable locally advanced ESCC. Methods: Unresectable locally advanced ESCC patients were randomized (1:1) to receive Nimo (400 mg, qw) or placebo in combination with concurrent chemo-radiotherapy (paclitaxel+ cisplatin+3DCRT/IMRT) for seven weeks. Patients were followed for five years.The primary endpoints were OS, and the secondary endpoints included ORR, DCR, PFS. Results: 200 patients were assigned to the Nimo group (n = 99) or placebo group (n = 101). An interim analysis was conducted for short term efficacy, i.e secondary endpoints (ORR, DCR) and safety, after completing the 6 months follow-up. The OS events are not enough for analysis. The two groups were comparable on baseline characteristics. Eighty patients in the Nimo group and eighty-two patients in the placebo group were evaluable. The ORR of the Nimo group (75/80, 93.8%) was significantly higher than the placebo group (59/82, 72.0%;Chi-square test, p < 0.001). Twenty-six patients in the Nimo group reached the complete response (CR), and ten placebo group patients were CR. The CR rate in the Nimo group was significantly higher than placebo group (32.5% vs.12.2%, p = 0.002). The DCR of the Nimo group and placebo group were 98.8% (79/80) and 91.5% (75/82), respectively (p = 0.064). Single factor logistic aggression analysis showed that age, sex, target lesion number, and BMI did not affect ORR, CR, and DCR (p > 0.05). Multiple factor correction analysis showed the difference of CR, ORR and DCR between two groups is 20% (95%CI 6.0%̃40.2%), 30% (95%CI 10.6%̃52.1%) and 10% (95%CI -5.2%̃31.1%). The incidence of grade 3-5 drug-related AEs was 11.1%vs.10.9% (p > 0.05). Common drug-related AEs in patients with Nimo plus chemo-radiotherapy treatment were leucopenia, neutrophilic granulocytopenia, thrombocytopenia, hemoglobin, bone marrow inhibition, nutritional anemia, and radioactive inflammation. Conclusions: This interim analysis showed that nimotuzumab in combination with chemo-radiotherapy is safe and can increase the CRR and ORR of the treated patients. The OS needs to be followed and finally analyzed. Clinical trial information: 02409186.

Identification of a thermophilic protease-producing strain and its application in solid-state fermentation of soybean meal

BACKGROUND

Thermophiles can thrive at 50-80 °C and produce some enzymes with special promise for biocatalysis. A thermophilic protease-producing strain YYC4 was isolated from Yunyan cigarette and employed in solid-state fermentation (SSF) of unsterilized soybean meal (SBM).

RESULTS

The isolate was identified as Bacillus licheniformis based on appearance of colonies, microscopic observation and 16S rDNA sequencing. After SSF, soluble and crude protein contents in SBM increased from 49.24 to 185.73 g kg-1 and from 404.18 to 479.46 g kg-1 , respectively, under the fermentation conditions of 107  cfu g-1 inoculation of strain YYC4, 1:1.8 (g mL-1 ) SBM to distilled water, 1.2 g kg-1 magnesium sulphate addition, 55 °C and 48 h. During fermentation, pH of the medium increased from 6.30 to 9.09 and protease activity especially neutral protease increased significantly from 13.5 to 181.31 U g-1 . Meanwhile, trypsin inhibitor (TI) activity was decreased from 8.19 to 3.19 mg g-1 . The safety of fermented SBM (FSBM) was verified by acute toxicity animal experiment. Analysis of microbial community in FSBM showed that Bacillus licheniformis YYC4 as a dominant strain inhibited most of the other microorganisms pre-existing in the materials during fermentation.

CONCLUSION

Increments of soluble and crude protein by 277.19% and 18.63% and decrement of harmful TI by 61.05% in SBM were achieved using thermophilic SSF by Bacillus licheniformis YYC4, providing a basis for the application of thermophiles in fermentation industry in an environmentally friendly and energy-saving way. © 2021 Society of Chemical Industry.

The selective breeding and mutagenesis mechanism of high-yielding surfactin Bacillus subtilis strains with atmospheric and room temperature plasma

BACKGROUND

Surfactin, a good biological surfactant, is derived from the metabolites of microorganisms. However, the ability of natural strains to produce surfactin is low, and so the presented study aimed to use a novel mutagenesis technology to increase their yields.

RESULTS

Atmospheric and room temperature plasma (ARTP) was used to conduct mutation breeding of Bacillus subtilis CICC 10721, and a mutant strain M45 with a higher surfactin yield of 34.2% and a stable subculture was screened out. From the fermentation kinetics study, it was found that the maximum cell dry weight, maximum growth rate and surfactin synthesis parameters of the mutant strain M45 were all greater than that of the original strain. Scanning electron microscope and laser scanning confocal microscope observations showed that the spore morphology changed after ARTP treating, and the intracellular Ca²⁺ concentration of the mutant increased. Genome resequencing analysis showed that 66 single nucleotide poymorphism non-synonymous mutation sites occurred in M45, and the identification results of the fermentation broth extract from M45 showed that it is composed of C₁₂ -C₁₆ surfactin.

CONCLUSION

ARTP mutagenesis was found to change the morphology of bacteria, membrane permeability and genes related to the synthesis and secretion of surfactin. The present study provides a basis for industrial production of surfactin and an understanding of the mutagenesis mechanism. © 2021 Society of Chemical Industry.

Effect of solid-state fermentation by three different Bacillus species on composition and protein structure of soybean meal

BACKGROUND

Fermentation efficiency of thermophiles of Bacillus licheniformis YYC4 and Geobacillus stearothermophilus A75, and mesophilic Bacillus subtilis 10 160 on soybean meal (SBM), was evaluated by examining the nutritional and protein structural changes.

RESULTS

SBM fermentation by B. licheniformis YYC4, B. subtilis 10 160 and G. stearothemophilus A75 increased significantly the crude and soluble protein from 442.4 to 524.8, 516.1 and 499.9 g kg-1 , and from 53.9 to 203.3, 291.3 and 74.6 g kg-1 , and decreased trypsin inhibitor from 8.19 to 3.19, 2.14 and 5.10 mg g-1 , respectively. Bacillus licheniformis YYC4 and B. subtilis 10 160 significantly increased phenol and pyrazine content. Furthermore, B. licheniformis YYC4 fermentation could produce abundant alcohols, ketones, esters and acids. Surface hydrophobicity, sulfhydryl groups and disulfide bond contents of SBM protein were increased significantly from 98.27 to 166.13, 173.27 and 150.71, from 3.26 to 4.88, 5.03 and 4.21 μmol g-1 , and from 20.77 to 27.95, 29.53 and 25.5 μmol g-1 after their fermentation. Fermentation induced red shifts of the maximum absorption wavelength (λmax ) of fluorescence spectra from 353 to 362, 376 and 361 nm, while significantly reducing the fluorescence intensity of protein, especially when B. subtilis 10 160 was used. Moreover, fermentation markedly changed the secondary structure composition of SBM protein. Analyses by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and atomic force microscopy showed that macromolecule protein was degraded into small-sized protein or peptide during fermentation of SBM.

CONCLUSION

Bacillus licheniformis YYC4 fermentation (without sterilization) improved nutrition and protein structure of SBM as B. subtilis 10 160, suggesting its potential application in the SBM fermentation industry. © 2021 Society of Chemical Industry.

TRIM50 Suppresses Pancreatic Cancer Progression and Reverses the Epithelial-Mesenchymal Transition via Facilitating the Ubiquitous Degradation of Snail1

Emerging evidence suggests that the tripartite motif (TRIM) family play important roles in tumor development and progression. Tripartite motif-containing 50 (TRIM50) is a member of the TRIM family, but little is known regarding its expression and potential functional roles in cancer. In this study, we first analyzed the expression pattern and clinical significance of TRIM50 in pancreatic cancer and found that TRIM50 expression is significantly reduced in pancreatic cancer tissues and its downregulation is associated with poor survival for pancreatic cancer patients. Functionally, TRIM50 overexpression in pancreatic cancer cells decreases their proliferation and motility capabilities and reverses the epithelial-mesenchymal transition (EMT) process, whereas TRIM50 depletion had the opposite effects. Mechanically, TRIM50 directly interacts with Snail1, a key regulator of EMT, and acts as an E3 ubiquitin ligase to target Snail1 for ubiquitous degradation. The function of TRIM50 in suppressing cell migration and EMT depends on TRIM50-promoted Snail1 degradation. In conclusion, our findings identify TRIM50 as a tumor suppressor that inhibits pancreatic cancer progression and reverses EMT via degrading Snail1 and provide new insights into the progression of pancreatic cancer.

P–568 Homozygous Pathogenic Variants in ACTL9 Cause Fertilization Failure and Male Infertility in Human and Mouse

Study question

What are the other male factors that cause total fertilization failure (TFF) excepting for variants in PLCZ1?

Summary answer

Homozygous variants in ACTL9 (actin like 9) cause abnormal localization of PLCζ in a loosened perinuclear theca (PT) structure and leads to TFF.

What is known already

In previous studies, investigators have reported that the female factors in TFF after intracytoplasmic sperm injection (ICSI) include pathogenic variants in WEE2, TLE6, and TUBB8, whereas for male factors, pathogenic variants in PLCZ1 were reported to be the primary cause of TFF, which account for approximately 30% of couples with male factors in TFF excluding globozoospermia. Most recently, it was reported that pathogenic variants in ACTL7A led to reduced expression and abnormal localization of PLCζ, thereby identifying this genetic variant as a potential cause of TFF.

Study design, size, duration

Fifty-four infertile couples with TFF or poor fertilization (fertilization rate of &lt; 20%) at the Reproductive and Genetic Hospital of CITIC-Xiangya during January 2014 to June 2020 were recruited into this study.

Participants/materials, setting, methods

Male factors were identified in (MOAT). WES analysis was used to analyze the genetic factors of individuals with male factors. Sperm morphological study was conducted by H&E staining and TEM. Immunostaining of PLCζ was used to analyze the status of sperm-borne activation factor. A knock-in mouse model was generated by CRISPER-Cas9 technology. Sperm from homozygous Actl9 variant mice were analyzed by TEM and ICSI. ICSI with AOA was performed in couples with ACTL9 variants.

Main results and the role of chance

A total of 54 couples with TFF or poor fertilization were screened, with 21 couples determined to have a male infertility factor by MOAT. Whole-exome sequencing of these 21 male individuals identified three homozygous pathogenic variants in ACTL9 in three individuals. ACTL9 variations led to abnormal ultrastructure of the PT, with PLCζ absent in the head and present in the neck of the mutant sperm, which contributed to failed normal calcium oscillations in oocytes and subsequent TFF. The key roles of ACTL9 in the PT structure and TFF after ICSI were further confirmed in Actl9-mutated mouse model. Furthermore, assisted oocyte activation by calcium ionophore exposure successfully overcame TFF and achieved live births in a couple with an ACTL9 variant.

Limitations, reasons for caution

The mechanism of how ACTL9 regulate PLCζ remains unknown.

Wider implications of the findings: It provided a genetic marker and a therapeutic option for individuals who have undergone ICSI without successful fertilization.

Trial registration number

not applioable

EUS-guided gastroenterostomy with a lumen apposing self-expandable metallic stent relieves gastric outlet obstruction - a Scandinavian case series

BACKGROUND

EUS-guided gastroenterostomy (EUS-GE) with lumen-apposing metallic stents (LAMS) in patients with gastric outlet obstruction (GOO) has proven to be an alternative to luminal stenting in the duodenum and surgical gastroenterostomy. In severely ill patients, the method can provide improved quality of life (QoL) and symptom relief by restoration of the luminal passage of fluid and nutrients to the small intestine.

AIM

To assess the technical and clinical success and safety of EUS-GE.

MATERIAL AND METHODS

A dual center retrospective case series of 33 consecutive patients with GOO due to malignant (n = 28) or non-malignant conditions (n = 5). The patients were treated with EUS-GE using cautery enhanced LAMS. Procedures were performed guided by EUS and fluoroscopy in general anesthesia or conscious sedation.

RESULTS

Technical success was achieved in all patients. The median procedure time was 71 min and the median hospital stay was three days. Thirty (91%) patients were able to resume oral nutrition after the procedure. Ten patients (30%) experienced adverse events (AEs), including migration of the stent, bleeding, and infection. Four patients had fatal AEs (12%). All stent-related AEs were handled endoscopically. Five patients (15%) needed re-intervention. The median survival time for patients with malignant obstruction was 8.5 weeks (0.5-76), and 13 patients with obstructing malignancies lived 12 weeks or longer.

CONCLUSION

EUS-GE is a minimally invasive and efficient method for restoration of the gastrointestinal passage and may improve palliative care for patients with GOO. The method has potential hazards and should only be offered in expert centers that regularly perform the procedure.

A phase I/II clinical trial on the efficacy and safety of NKT cells combined with gefitinib for advanced EGFR-mutated non-small-cell lung cancer

Background

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), such as gefitinib, have achieved good efficacy in EGFR mutation-positive non-small-cell lung cancer (NSCLC) patients, but eventual drug resistance is inevitable. Thus, new TKI-based combination therapies should be urgently explored to extend the overall survival time of these patients. CD8 + CD56+ natural killer T (NKT) cells are a natural and unique subset of lymphocytes in humans that present characteristics of T and NK cells and exert cytotoxicity on tumour cells in a granzyme B-dependent manner. The aim of this trial was to explore the efficacy and safety of CD8 + CD56+ NKT cell immunotherapy combined with gefitinib in patients with advanced EGFR-mutated NSCLC.

Methods

The study was designed as a prospective, randomized, controlled, open-label, phase I/II trial that includes 30 patients with EGFR mutation-positive stage III/IV NSCLC. All patients will be randomized in blocks at a 1:1 ratio and treated with gefitinib 250 mg/day monotherapy or combination therapy with allogeneic CD8 + CD56+ NKT cell infusions twice per month for 12 cycles or until disease progression occurs. The effectiveness of this treatment will be evaluated based on by progression-free survival (PFS), the time to progression (TTP), overall response rate (ORR), disease control rate (DCR) and overall survival (OS). The safety of the trail is being assessed based on adverse events (AEs). Recruitment and data collection, which started in December 2017, are ongoing.

Discussion

Although immunotherapy, including programmed death-1/programmed death-1 ligand (PD-1/PD-L1) immunotherapy, has been used for NSCLC treatment with or without EGFR-TKIs, its clear efficacy still has not been shown. Assessing the safety and therapeutic potential of allogeneic CD8 + CD56+ NKT killer cells in combination with EGFR-TKIs in NSCLC will be of great interest.

Trial registration

This trial (Phase I/II Trails of NKT Cell in Combination With Gefitinib For Non Small Cell Lung Cancer) was registered on 21 November 2017 with www.chictr.org.cn, ChiCTR-IIR-17013471.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08590-1.

Targeting Purinergic Receptor P2RX1 Modulates Intestinal Microbiota and Alleviates Inflammation in Colitis

Inflammatory bowel disease (IBD) remains one of the most prevalent gastrointestinal diseases worldwide. Purinergic signaling has emerged as a promising therapeutic target of inflammation-associated diseases. However, little is known about the specific roles of purinergic receptors in IBD. In the present study, expression profile of purinergic receptors was screened in the public Gene Expression Omnibus (GEO) datasets, and we found that expression of P2RX1 was significantly upregulated in inflamed colon tissues. Then, purinergic receptor P2RX1 was genetically ablated in the background of C57BL/6 mice, and dextran sulfate sodium (DSS) was used to induce mice colitis. RNA sequencing results of colon tissues showed that genetic knockout of P2RX1 suppressed the inflammation responses in DSS-induced mice colitis. Flow cytometry indicated that neutrophil infiltration was inhibited in P2RX1 ablated mice. 16S ribosomal DNA sequencing revealed major differences of intestinal microbiota between WT and P2RX1 ablated mice. Functional metagenomics prediction indicated that the indole alkaloid biogenesis pathway was upregulated in P2RX1 gene ablated mice. Further studies revealed that microbiota metabolites (indole alkaloid)-involved aryl hydrocarbon receptor (AhR)/IL-22 axis was associated with the beneficial effects of P2RX1 ablation. Finally, we found that a specific P2RX1 inhibitor succeeded to improve the therapeutic efficiency of anti-TNF-α therapy in DSS-induced mice colitis. Therefore, our study suggests that targeting purinergic receptor P2RX1 may provide novel therapeutic strategy for IBD.

A compact electron beam ion trap in support of high-temperature plasma diagnostics based on conduction-cooled superconducting coils

Spectroscopic diagnostics of future fusion reactor plasmas require information on impurity line emissions, especially for relevant high-Z metal elements (e.g., tungsten). These materials will be widely used as plasma facing components for their high heat tolerance and low sputtering yield. Based on an electron beam ion trap, a compact impurity spectra platform is developed to mimic the high-temperature environment of a fusion reactor. The proposed platform can deliver a focused e-beam at energies over 30 keV using a confining magnetic field of ∼1.0 T generated by two superconducting coils (NbTi). Cooled by a closed-loop cryocooler, the coils can avoid the usage of a complicated cryogenic system involving the handling of liquid helium. For spectroscopic studies of highly charged ions, a spherically curved crystal spectrometer is proposed to measure a wavelength range around 2-4 Å covering the typical wavelength range expected to be emitted by metal ions in a fusion plasma. This paper reports the design and development progress of the platform.

P2RX1-Involved Glycolytic Metabolism Supports Neutrophil Activation in Acute Pancreatitis

Acute pancreatitis (AP) is characterized by disordered inflammation of the pancreas, and the underlying mechanisms remain unclear. Purinergic signaling plays crucial roles in initiating and amplifying inflammatory signals. Recent evidence reveals that targeting dysregulated purinergic signaling is promising for treating inflammation-associated diseases. To explore the potential involvement of purinergic signaling in AP, we investigated the expression profiles of purinergic signaling molecules in human and mouse pancreas tissues. Results showed that purinergic receptor P2RX1 was among the most highly expressed genes in both human and mouse pancreas tissues. Genetic ablation or specific antagonism of P2RX1 markedly alleviated inflammatory responses in caerulein-induced AP mice. Bone marrow chimeras and adoptive transfer studies revealed that neutrophil-derived P2RX1 contributed to the inflammatory responses in AP. Further studies demonstrated that P2RX1 promoted neutrophil activation by facilitating glycolytic metabolism. Therefore, our study indicates that purinergic receptor P2RX1 may be a potential therapeutic target to treat disordered inflammation in AP.

Fully Automatic Sliding Motion Compensated and Simultaneous 4D-CBCT via Bilateral Filtering

Purpose

To incorporate the bilateral filtering into the Deformable Vector Field (DVF) based 4D-CBCT reconstruction for realizing a fully automatic sliding motion compensated 4D-CBCT.

Materials and Methods

Initially, a motion compensated simultaneous algebraic reconstruction technique (mSART) is used to generate a high quality reference phase (e.g. 0% phase) by using all phase projections together with the initial 4D-DVFs. The initial 4D-DVF were generated via Demons registration between 0% phase and each other phase image. The 4D-DVF will then kept updating by matching the forward projection of the deformed high quality 0% phase with the measured projection of the target phase. The loss function during this optimization contains an projection intensity difference matching criterion plus a DVF smoothing constrain term. We introduce a bilateral filtering kernel into the DVF constrain term to estimate the sliding motion automatically. The bilateral filtering kernel contains three sub-kernels: 1) an spatial domain Guassian kernel; 2) an image intensity domain Guassian kernel; and 3) a DVF domain Guassian kernel. By choosing suitable kernel variances, the sliding motion can be extracted. A non-linear conjugate gradient optimizer was used. We validated the algorithm on a non-uniform rotational B-spline based cardiac-torso (NCAT) phantom and four anonymous patient data. For quantification, we used: 1) the Root-Mean-Square-Error (RMSE) together with the Maximum-Error (MaxE); 2) the Dice coefficient of the extracted lung contour from the final reconstructed images and 3) the relative reconstruction error (RE) to evaluate the algorithm's performance.

Results

For NCAT phantom, the motion trajectory's RMSE/MaxE are 0.796/1.02 mm for bilateral filtering reconstruction; and 2.704/4.08 mm for original reconstruction. For patient pilot study, the 4D-Dice coefficient obtained with bilateral filtering are consistently higher than that without bilateral filtering. Meantime several image content such as the rib position, the heart edge definition, the fibrous structures all has been better corrected with bilateral filtering.

Conclusion

We developed a bilateral filtering based fully automatic sliding motion compensated 4D-CBCT scheme. Both digital phantom and initial patient pilot studies confirmed the improved motion estimation and image reconstruction ability. It can be used as a 4D-CBCT image guidance tool for lung SBRT treatment.

RIPK3-mediated inflammation is a conserved β cell response to ER stress

Islet inflammation is an important etiopathology of type 2 diabetes; however, the underlying mechanisms are not well defined. Using complementary experimental models, we discovered RIPK3-dependent IL1B induction in β cells as an instigator of islet inflammation. In cultured β cells, ER stress activated RIPK3, leading to NF-kB-mediated proinflammatory gene expression. In a zebrafish muscle insulin resistance model, overnutrition caused islet inflammation, β cell dysfunction, and loss in an ER stress-, ripk3-, and il1b-dependent manner. In mouse islets, high-fat diet triggered the IL1B expression in β cells before macrophage recruitment in vivo, and RIPK3 inhibition suppressed palmitate-induced β cell dysfunction and Il1b expression in vitro. Furthermore, in human islets grafted in hyperglycemic mice, a marked increase in ER stress, RIPK3, and NF-kB activation in β cells were accompanied with murine macrophage infiltration. Thus, RIPK3-mediated induction of proinflammatory mediators is a conserved, previously unrecognized β cell response to metabolic stress and a mediator of the ensuing islet inflammation.

SARS-CoV-2 Cell Entry Factors ACE2 and TMPRSS2 Are Expressed in the Microvasculature and Ducts of Human Pancreas but Are Not Enriched in β Cells

Isolated reports of new-onset diabetes in individuals with COVID-19 have led to the hypothesis that SARS-CoV-2 is directly cytotoxic to pancreatic islet β cells. This would require binding and entry of SARS-CoV-2 into β cells via co-expression of its canonical cell entry factors, angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2); however, their expression in human pancreas has not been clearly defined. We analyzed six transcriptional datasets of primary human islet cells and found that ACE2 and TMPRSS2 were not co-expressed in single β cells. In pancreatic sections, ACE2 and TMPRSS2 protein was not detected in β cells from donors with and without diabetes. Instead, ACE2 protein was expressed in islet and exocrine tissue microvasculature and in a subset of pancreatic ducts, whereas TMPRSS2 protein was restricted to ductal cells. These findings reduce the likelihood that SARS-CoV-2 directly infects β cells in vivo through ACE2 and TMPRSS2.

SARS-CoV-2 Cell Entry Factors ACE2 and TMPRSS2 are Expressed in the Pancreas but are Not Enriched in Islet Endocrine Cells

Reports of new-onset diabetes and diabetic ketoacidosis in individuals with COVID-19 have led to the hypothesis that SARS-CoV-2, the virus that causes COVID-19, is directly cytotoxic to pancreatic islet β cells. This would require binding and entry of SARS-CoV-2 into host β cells via cell surface co-expression of ACE2 and TMPRSS2, the putative receptor and effector protease, respectively. To define ACE2 and TMPRSS2 expression in the human pancreas, we examined six transcriptional datasets from primary human islet cells and assessed protein expression by immunofluorescence in pancreata from donors with and without diabetes. ACE2 and TMPRSS2 transcripts were low or undetectable in pancreatic islet endocrine cells as determined by bulk or single cell RNA sequencing, and neither protein was detected in α or β cells from these donors. Instead, ACE2 protein was expressed in the islet and exocrine tissue microvasculature and also found in a subset of pancreatic ducts, whereas TMPRSS2 protein was restricted to ductal cells. The absence of significant ACE2 and TMPRSS2 co-expression in islet endocrine cells reduces the likelihood that SARS-CoV-2 directly infects pancreatic islet β cells through these cell entry proteins.

Effect of dual-frequency ultrasound on the formation of lysinoalanine and structural characterization of rice dreg protein isolates

The effect of dual-frequency ultrasound treatment with different working modes on the lysinoalanine (LAL) formation and structural characterization of rice dreg protein isolates (RDPI) was studied during alkaline exaction processing. Ultrasonic notably decreased the LAL amount of RDPI and enhanced the protein dissolution rate. The LAL content of RDPI, especially sequential dual frequency 20/40 kHz, decreased by 12.02% (P < 0.05), compared to non-sonicated samples. Herein, the protein dissolution rate was higher. The changes in sulfhydryl groups was positively correlated with the LAL formation. The amino acids (AA) such as threonine (Thr), lysine (Lys), and arginine (Arg) were reduced, resulting in a decrease in LAL content following sonication. Besides, ultrasonication altered protein secondary structure by reducing random coil and β-sheet contents, while α-helix and β-turn contents increased. Alterations in the surface hydrophobicity, particle size, particle size distribution, and microstructure indicated more irregular fragment with microparticles of RDPI by sonochemical treatment. Thus, ultrasound treatment may be a new and efficacious process for controlling the LAL generation in prepared-protein food(s) during alkali extraction.

Dapagliflozin Does Not Directly Affect Human α or β Cells

Selective inhibitors of sodium glucose cotransporter-2 (SGLT2) are widely used for the treatment of type 2 diabetes and act primarily to lower blood glucose by preventing glucose reabsorption in the kidney. However, it is controversial whether these agents also act on the pancreatic islet, specifically the α cell, to increase glucagon secretion. To determine the effects of SGLT2 on human islets, we analyzed SGLT2 expression and hormone secretion by human islets treated with the SGLT2 inhibitor dapagliflozin (DAPA) in vitro and in vivo. Compared to the human kidney, SLC5A2 transcript expression was 1600-fold lower in human islets and SGLT2 protein was not detected. In vitro, DAPA treatment had no effect on glucagon or insulin secretion by human islets at either high or low glucose concentrations. In mice bearing transplanted human islets, 1 and 4 weeks of DAPA treatment did not alter fasting blood glucose, human insulin, and total glucagon levels. Upon glucose stimulation, DAPA treatment led to lower blood glucose levels and proportionally lower human insulin levels, irrespective of treatment duration. In contrast, after glucose stimulation, total glucagon was increased after 1 week of DAPA treatment but normalized after 4 weeks of treatment. Furthermore, the human islet grafts showed no effects of DAPA treatment on hormone content, endocrine cell proliferation or apoptosis, or amyloid deposition. These data indicate that DAPA does not directly affect the human pancreatic islet, but rather suggest an indirect effect where lower blood glucose leads to reduced insulin secretion and a transient increase in glucagon secretion.

Decreased pancreatic acinar cell number in type 1 diabetes

AIMS/HYPOTHESIS

Individuals with longstanding and recent-onset type 1 diabetes have a smaller pancreas. Since beta cells represent a very small portion of the pancreas, the loss of pancreas volume in diabetes is primarily due to the loss of pancreatic exocrine mass. However, the structural changes in the exocrine pancreas in diabetes are not well understood.

METHODS

To characterise the pancreatic endocrine and exocrine compartments in diabetes, we studied pancreases from adult donors with type 1 diabetes compared with similarly aged donors without diabetes. Islet cell mass, islet morphometry, exocrine mass, acinar cell size and number and pancreas fibrosis were assessed by immunohistochemical staining. To better understand possible mechanisms of altered pancreas size, we measured pancreas size in three mouse models of insulin deficiency.

RESULTS

Pancreases from donors with type 1 diabetes were approximately 45% smaller than those from donors without diabetes (47.4 ± 2.6 vs 85.7 ± 3.7 g), independent of diabetes duration or age of onset. Diabetic donor pancreases had decreased beta cell mass (0.061 ± 0.025 vs 0.94 ± 0.21 g) and reduced total exocrine mass (42.0 ± 4.9 vs 96.1 ± 6.5 g). Diabetic acinar cells were similar in size but fewer in number compared with those in pancreases from non-diabetic donors (63.7 ± 8.1 × 10⁹ vs 121.6 ± 12.2 × 10⁹ cells/pancreas), likely accounting for the difference in pancreas size. Within the type 1 diabetes exocrine tissue, there was a greater degree of fibrosis. The pancreases in three mouse models of insulin deficiency were similar in size to those in control mice.

CONCLUSIONS/INTERPRETATION

Pancreases from donors with type 1 diabetes are smaller than normal donor pancreases because exocrine cells are fewer in number rather than smaller in size; these changes occur early in the disease process. Our mouse data suggest that decreased pancreas size in type 1 diabetes is not directly caused by insulin deficiency, but the precise mechanism responsible remains unclear.