Parallel ß-Sheet Structure and Structural Heterogeneity Detected within Q11 Self-Assembling Peptide Nanofibers.

Q11 peptide nanofibers are used as a biomaterial for applications such as antigen presentation and tissue engineering, yet detailed knowledge of molecular-level structure has not been reported. The Q11 peptide sequence was designed using heuristics-based patterning of hydrophobic and polar amino acids with oppositely charged amino acids placed at opposite ends of the sequence to promote antiparallel ß-sheet formation. In this work, we employed solid-state nuclear magnetic resonance spectroscopy (NMR) to evaluate whether the molecular organization within Q11 self-assembled peptide nanofibers is consistent with the expectations of the peptide designers. We discovered that Q11 forms a distribution of molecular structures. NMR data from two-dimensional (2D) 13C-13C dipolar-assisted rotational resonance indicate that the K3 and E9 residues between Q11 ß-strands are spatially proximate (within ∼0.6 nm). Frequency-selective rotational echo double resonance (fsREDOR) on K3 Nζ and E9 Cδ-labeled sites showed that approximately 9% of the sites are close enough for salt bridge formation to occur. Surprisingly, dipolar recoupling measurements revealed that Q11 peptides do not assemble into antiparallel ß-sheets as expected, and structural analysis using Fourier-transform infrared spectroscopy and 2D NMR alone can be misleading. 13C PITHIRDS-CT dipolar recoupling measurements showed that the most abundant structure consists of parallel ß-sheets, in contrast to the expected antiparallel ß-sheet structure. Structural heterogeneity was detected from 15N{13C} REDOR measurements, with approximately 22% of ß-strands having antiparallel nearest neighbors. We cannot propose a complete structural model of Q11 nanofibers because of the complexity involved when examining structurally heterogeneous samples using NMR. Altogether, our results show that while heuristics-based patterning is effective in promoting ß-sheet formation, designing a peptide sequence to form a targeted ß-strand arrangement remains challenging.

Side-Chain Chemistry Governs Hierarchical Order of Charge-Complementary ß-sheet Peptide Coassemblies.

Self-assembly of proteinaceous biomolecules into functional materials with ordered structures that span length scales is common in nature yet remains a challenge with designer peptides under ambient conditions. This report demonstrates how charged side-chain chemistry affects the hierarchical co-assembly of a family of charge-complementary ß-sheet-forming peptide pairs known as CATCH(X+/Y-) at physiologic pH and ionic strength in water. In a concentration-dependent manner, the CATCH(6K+) (Ac-KQKFKFKFKQK-Am) and CATCH(6D-) (Ac-DQDFDFDFDQD-Am) pair formed either ß-sheet-rich microspheres or ß-sheet-rich gels with a micron-scale plate-like morphology, which were not observed with other CATCH(X+/Y-) pairs. This hierarchical order was disrupted by replacing D with E, which increased fibril twisting. Replacing K with R, or mutating the N- and C-terminal amino acids in CATCH(6K+) and CATCH(6D-) to Qs, increased observed co-assembly kinetics, which also disrupted hierarchical order. Due to the ambient assembly conditions, active CATCH(6K+)-green fluorescent protein fusions could be incorporated into the ß-sheet plates and microspheres formed by the CATCH(6K+/6D-) pair, demonstrating the potential to endow functionality.

[Study on the original Chinese Version of Da sheng bian (A Treatise on Midwifery) translated by William Lockhart].

William Lockhart's A Treatise on Midwifery, published in 1842, is the first English translation Monograph of ancient obstetric book in traditional Chinese medicine.To take the translation postscript as clue, adopt research methods like textual bibliography etc., and integrate the relevant historical data and the libraries collection information, it is found that the original version of the English translation is the carving copy of Da Sheng Bian engraved by Fuxian Hall on Rongxian Street, Foxian County,Guangdong Province, in the fifth year of the reign of Emperor Daoguang of the Qing Dynasty (1825). It is now collected in the National Library of Australia and the Dun's Library of the Royal College of Physicians of Ireland, and the sources of both collections are related to William Lockhart.

Dietary cholecalciferol and 25-hydroxycholecalciferol supplementation interact to modulate reproductive performance, egg quality, serum antioxidant capacity, intestinal morphology and tibia quality of breeder geese.

1. A study was conducted to evaluate the effects of dietary cholecalciferol (vitamin D3) and 25-hydroxycholecalciferol (25-OH-D3) supplementation on the reproductive performance, egg quality, eggshell ultrastructure, serum hormone level and antioxidant capacity, intestinal morphology and tibia quality of breeder geese during the laying period.2. The trial was designed as a 3 × 3 factorial arrangement with three levels (300, 400 and 500 IU/kg) of vitamin D3 supplementation and three levels (25, 50 and 75 µg/kg) of 25-OH-D3 supplementation in a 10-wk feeding trial.3. The results showed that the combined supplementation of 400 IU/kg vitamin D3 and 50 µg/kg 25-OH-D3 had a better feed conversion ratio and a higher egg laying rate than the other groups. Vitamin D3 supplementation significantly increased the rate of qualified eggs for hatching, eggshell strength and thickness, serum testosterone and progesterone levels, serum total superoxide dismutase and glutathione peroxidase activities, tibia ash content and bone mineral density (P < 0.05). Dietary 25-OH-D3 supplementation significantly increased serum glutathione peroxidase activity and duodenal villus height and villus height-to-crypt-depth ratio (P < 0.05). The geese receiving 500 IU/kg vitamin D3 and 75 µg/kg 25-OH-D3 had the highest tibia calcium and phosphorous content among all groups (P < 0.05).4. Feeding 400 IU/kg vitamin D3 plus 50 µg/kg 25-OH-D3 gave optimal effects on feed conversion ratio and egg laying rate. This combination could be a nutritional strategy for increasing the laying rate, eggshell quality, serum hormone levels and serum antioxidant function regardless of 25-OH-D3 supplementation. Supplementation of 50 µg/kg 25-OH-D3 could be a recommended dose for improving the serum antioxidant capacity and intestinal morphology regardless of vitamin D3 supplementation.

[Clinical observation of bow-tie adjustable suture technique for overcorrection in intermittent exotropia].

Objective: To investigate the clinical effects of the bow-tie adjustable suture technique in managing overcorrection in patients with intermittent exotropia after surgery. Methods: This was a retrospective case series study. Clinical data were collected from children with intermittent exotropia who underwent strabismus correction surgery, including the bow-tie adjustable suture technique and conventional techniques, at the Department of Strabismus and Pediatric Ophthalmology, Shanxi Eye Hospital, from January 2020 to September 2021. Children with postoperative esodeviation≥15 prism diopters (PD) within the first 6 days were treated differently based on the surgical technique and their individual conditions, including suture adjustment and conservative treatment. The overcorrection rate and its changes among different surgical groups, the recovery of ocular alignment and binocular visual function after different treatment methods in children with overcorrection on the sixth postoperative day, and the postoperative complications in different surgical groups were observed. Statistical analysis was performed using independent samples t-test, Wilcoxon rank-sum test, repeated-measures analysis of variance, Bonferroni test, chi-square test, or Fisher's exact probability test, as appropriate. Results: A total of 643 children who underwent intermittent exotropia correction surgery were included in the study. Among them, 325 children underwent the bow-tie adjustable suture technique, with 185 males and 140 females, and the mean age was (9.50±2.69) years. The remaining 318 children underwent conventional techniques, with 176 males and 142 females, and the mean age was (9.90±2.67) years. There were no statistically significant differences in age and gender distribution between the two surgical groups (all P>0.05). On the first postoperative day, among children who underwent the bow-tie adjustable suture technique, 40 had an esodeviation of≥10 PD, resulting in an overcorrection rate of 12.3% (40/325), while among children who underwent conventional techniques, 32 had an esodeviation of≥10 PD, resulting in an overcorrection rate of 10.1% (32/318). On the sixth postoperative day, these rates decreased to 5.5% (18/325) and 3.1% (10/318) in the two groups, respectively. At 1, 6, and 12 months postoperatively, the overcorrection rate in children who underwent the bow-tie adjustable suture technique was 0, while in children who underwent conventional techniques, the overcorrection rate did not show a significant decrease compared to before surgery. The differences between the two surgical groups were statistically significant (all P<0.05). On the sixth postoperative day, among children with an esodeviation of≥15 PD, 13 underwent suture adjustment and 7 received conservative treatment. The results of repeated-measures analysis of variance showed statistically significant differences in near and distance esodeviation angles among children who received different treatment methods (F=145.20, 106.87, both P<0.001), as well as statistically significant differences in near and distance esodeviation angles at different time points within each group of children (F=81.67, 35.09, both P<0.001). There were also significant differences in the trends of change in near and distance esodeviation angles at different time points among children who received different treatment methods (F=79.90, 36.73, both P<0.001). Further pairwise comparisons showed significant differences in near and distance esodeviation angles between the sixth postoperative day and 1, 6, and 12 months postoperatively in children who underwent suture adjustment (all P<0.05), while no statistically significant differences were observed in children who received conservative treatment (all P>0.05). At 12 months postoperatively, among the 13 children who underwent suture adjustment, 12 achieved stereopsis, while among the 7 children who received conservative treatment, all became stereo-blind after removing the prismatic correction. No serious complications occurred in any of the children postoperatively. Conclusion: The proportion of children with intermittent exotropia who achieved orthotropic alignment one year after surgery was relatively low among those who had an overcorrection of≥15 PD on the sixth postoperative day. The bow-tie adjustable suture technique is a simple and effective approach for managing overcorrection in patients with intermittent exotropia. Adjusting the sutures on the sixth postoperative day can reduce the overcorrection rate and is considered a safe and effective method.

Evaluation of cold atmospheric plasma for the decontamination of flexible endoscopes.

BACKGROUND: Despite adherence to standard protocols, residues including live micro-organisms may remain on the various surfaces of reprocessed flexible endoscopes. Prions are infectious proteins that are notoriously difficult to eliminate. AIM: To test the potential of cold atmospheric plasma (CAP) for the decontamination of various surfaces of flexible endoscopes, measuring total proteins and prion residual infectivity as indicators of efficacy. METHODS: New PTFE endoscope channels and metal test surfaces spiked with test soil or prion-infected tissues were treated using different CAP-generating prototypes. Surfaces were examined for the presence of residues using very sensitive fluorescence epimicroscopy. Prion residual infectivity was determined using the wire implant animal model and a more sensitive cell infectivity assay. FINDINGS: A CAP jet applied perpendicularly at close range on flat test surfaces removed soil within 3 min, but left microscopic residues and failed to eliminate prion infectivity according to the wire implant animal assay. The longitudinal gas flow from CAP prototypes developed for the treatment of long channels led to the displacement and sedimentation of residual soil towards the distal end, when applied alone. Observations of the plasma inside glass tubes showed temporal and spatial heterogeneity within a limited range. After the standard enzymatic manual pre-wash, 'CAP-activated' gas effluents prevented prion transmission from treated endoscope channels according to the prion infectivity cell assay. CONCLUSION: CAP shows promising results as a final step for decontamination of surgical surfaces. Optimizing CAP delivery could further enhance CAP efficacy, offering a safe, chemical-free alternative for the reprocessing of all luminal flexible endoscope surfaces.

Impact of human coronavirus infections on paediatric patients at a tertiary paediatric hospital: a retrospective study of the prepandemic era.

BACKGROUND: Human coronaviruses (HCoVs) are important respiratory pathogens in humans and animals. Most HCoVs are emerging pathogens, with five known human pathogens identified in the last two decades. AIM: To examine the clinical course of HCoV infection in children to improve understanding of severity and outcomes. METHODS: A retrospective review was undertaken of all encounters of children with known HCoV infection at a tertiary paediatric hospital from January 2015 to January 2018. Electronic medical records were reviewed for demographic data, HCoV type, viral co-pathogens, time to testing, need for hospitalization, requirement for higher-level care (HLC) including intensive care unit management and requirement for oxygen support, radiographic findings suggestive of lower respiratory tract (LRT) disease, and length of stay (LOS). FINDINGS: In total, 450 encounters for 430 different patients were identified, with the majority (85%) being inpatient. OC43 was the most common HCoV. Younger patients (age <5 years) had higher probability of hospitalization [adjusted odds ratio (aOR) 2.2, 95% confidence interval (CI) 1.2-4.1], requirement for HLC (aOR 1.8, 95% CI 1.0-3.1) and presence of LRT findings on chest radiographs (aOR 1.7, 95% CI 1.01-2.9). Clinical outcomes did not differ between HCoV types, except LOS which was longer for 229E. Fifty-two (11%) encounters were detected after 3 days of hospitalization (median 25.5 days), suggesting possible nosocomial infection. CONCLUSION: HCoVs are important respiratory pathogens in the paediatric population, especially among patients aged <5 years who are at increased risk for severe disease. The role of HCoVs as hospital-acquired pathogens may be underappreciated.

[Periodic dynamic observation and analysis of cellular and humoral immunity indexes of adults infected with Omicron BA.1].

Objective: To analyze the immunological characteristics and antibody changes of patients infected with the Omicron BA.1 and evaluate the possibility of secondary infection. Methods: A total of 104 patients infected with Omicron BA.1 in the Jinnan District of Tianjin from January 8 to February 2, 2022, were included in the study. The control group and case group were matched 1∶1 based on age, sex and vaccination status. Serum was collected from the case group and control group at 3, 6 and 9 months after infection. The serum levels of interleukin4 (IL-4), IL-5 and interferon-gamma (IFN-γ), as well as the positive rates of IgG, IgG1 and IgG2, were detected by ELISA. Results: The highest concentration of IFN-γ in the case group at 6 months after infection was 145.4 pg/ml, followed by a decrease in concentration. The concentrations of IL-4 and IL-5 began to decrease at 6 months after infection (all P<0.001). There was no significant difference in the IgG2 positive rate between the case group and the control group at 6 months after BA.1 infection. However, at 9 months, there was a significant decrease compared to the control group (P=0.003). The ratio of IFN-γ/IL4 at 3 months after infection in the case group was lower than that in the control group (P<0.001). There was no significant difference in the ratio between the case group and the control group at 9 months after infection. Conclusion: The cellular immune function has been impaired at 3 months after infection with BA.1, and the specific cellular immune and humoral immune functions decrease significantly after 6 months, and the risk of secondary infection increases.

[Progress in the treatment of sarcopenia in patients with cirrhosis].

Sarcopenia, a common complication of cirrhosis, has an incidence rate as high as 40% ~ 70%. Furthermore, adverse events such as shortened survival, lower quality of life, prolonged hospital stay, increased complications, a higher mortality rate, and sometimes altering the liver transplantation prognostic outcome in patients with liver cirrhosis are closely related. In recent years, some progress has been made in the research on the treatment of sarcopenia, but there is no clear treatment plan at present; thus, research and development by researchers and clinicians still need to be strengthened. This article briefly describes the relevant treatment methods for sarcopenia in patients with cirrhosis.

[Short-term outcomes of prism treatment in a manner of reducing prism diopters step by step for small-angle acute acquired concomitant esotropia].

Objective: To investigate the short-term efficacy of the prism treatment in a manner of reducing prism diopters step by step for small-angle acute acquired concomitant esotropia (AACE). Methods: Retrospective case series study. The clinical data of 17 AACE patients with strabismus ≤25 prism degrees (PD) including 6 males and 11 females, aged 14 to 60 years, who underwent the prism treatment in the Strabismus and Pediatric Ophthalmology Clinic of Shanxi Eye Hospital from October 2018 to June 2020 were collected. The prism treatment was conducted by a step-by-step reduction of prism diopters. An under-corrected prism was applied to the patient for the first time, and the degree of the prism was reduced gradually with the decrease in the degree of strabismus. Statistical analysis was performed after 6 months of treatment. The treatment success was defined as obtaining orthotropia and deleting diplopia when prism glasses were weaned off. The strabismus degree, Worth 4 dot test results, near stereopsis (Titmus stereopsis) and synoptophore fusion function before and after treatment were compared, and the factors affecting the curative effect were analyzed. Statistical methods mainly included paired t-test, Wilcoxon rank sum test, the Fisher exact test and univariate logistic regression analysis. Results: Among these 17 patients, 15 had myopia and 2 had emmetropia. Pretherapeutic esodeviation was (13.94±5.83) PD at near (33 cm), and was (15.76±5.24) PD at distance (6 m). After 6 months of treatment, 7 patients were successfully cured. The deviation angle at distance [(10.60±7.16) PD] and near [(9.80±6.00) PD] of the remaining 10 patients at 6 months after prismatic treatment was significantly smaller than that before treatment [(17.50±5.40) PD and (16.10±5.47) PD; t=3.69, 4.10; both P<0.01]. The Titmus stereogram showed that 2 cases had no stereopsis, 6 cases had peripheral stereopsis, 3 cases had macular stereopsis, and 6 cases had foveal stereopsis before treatment. Stereopsis was significantly improved at 6 months after prismatic treatment, with 3 cases havimg macular stereopsis and 14 cases having foveal stereopsis (Z=-2.99; P<0.01). The Worth-4-dot test disclosed that, the number of patients who saw four lamps at distance and near was 0 and 2 before treatment, and 7 and 9 after treatment, respectively, and the difference was statistically significant (both P<0.05). The divergent fusional amplitude and convergent fusional amplitude in the synoptophore at 6 month after treatment was not significantly different from that before treatment (both P>0.05). The efficacy of treatment was not significantly related to the duration from onset to treatment, the pretherapeutic esodeviation, the Titmus stereoacuity, cycloplegic refractive error, and age (all P>0.05). None of the 7 patients, who were successfully cured had a recurrence of esotropia or diplopia during the observation period of 6 to 24 months (median, 11 months). Conclusions: Prism treatment in a manner of step-by-step reduction of prism diopters can significantly diminish the degree of esotropia and improve the binocular function in small-angle AACE. Furthermore, some patients could be cured, achieving orthophoria without diplopia.

Hand hygiene behaviours monitored by an electronic system in the intensive care unit - a prospective observational study.

BACKGROUND: It is difficult to improve compliance with hand hygiene (HH), and underlying behaviours are not clearly understood among healthcare workers. AIM: To study HH behaviours among healthcare workers. METHODS: This was a prospective observational study. A Sanibit electronic HH system was installed in a 10-bed surgical intensive care unit (ICU) that detected HH opportunities automatically when healthcare workers entered or exited a patient room, and tracked the HH compliance of healthcare workers. The HH compliance rate and patient contact time were calculated and analysed at both ICU level and individual level over time. FINDINGS: In total, 27,692 HH opportunities were recorded over this 6-month trial period. The HH compliance rate was significantly higher when healthcare workers exited patient rooms than when they entered patient rooms (37.3% vs 26.1%; P<0.001). Full, partial and total HH compliance rates of 'quick in and quick out' (in room for <3 s) events were significantly lower than those of 'long in and long out' (in room for >30 s) events (23.45% vs 32.77%, 21.44% vs 35.03% and 44.88% vs 67.81%, respectively; P<0.001). There were also significant differences in HH compliance between individual healthcare workers (P<0.001). No significant differences in overall HH compliance rate and patient contact time were found between hours of the day or days of the week, except partial HH compliance rates. CONCLUSION: Patterns of HH behaviours among healthcare workers are complex and variable, which could facilitate targeted and personalized interventions to improve HH compliance. CLINICAL TRIAL REGISTRATION: NCT03948672.

Validation of a Novel Multitarget Blood Test Shows High Sensitivity to Detect Early Stage Hepatocellular Carcinoma.

BACKGROUND & AIMS: Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death worldwide. Although biannual ultrasound surveillance with or without α-fetoprotein (AFP) testing is recommended for at-risk patients, sensitivity for early stage HCC, for which potentially curative treatments exist, is suboptimal. We conducted studies to establish the multitarget HCC blood test (mt-HBT) algorithm and cut-off values and to validate test performance in patients with chronic liver disease. METHODS: Algorithm development and clinical validation studies were conducted with participants in an international, multicenter, case-control study. Study subjects had underlying cirrhosis or chronic hepatitis B virus; HCC cases were diagnosed per the American Association for the Study of Liver Diseases criteria and controls were matched for age and liver disease etiology. Whole blood and serum were shipped to a central laboratory and processed while blinded to case/control status. An algorithm was developed for the mt-HBT, which incorporates methylation biomarkers (HOXA1, TSPYL5, and B3GALT6), AFP, and sex. RESULTS: In algorithm development, with 136 HCC cases (60% early stage) and 404 controls, the mt-HBT showed 72% sensitivity for early stage HCC at 88% specificity. Test performance was validated in an independent cohort of 156 HCC cases (50% early stage) and 245 controls, showing 88% overall sensitivity, 82% early stage sensitivity, and 87% specificity. Early stage sensitivity in clinical validation was significantly higher than AFP at 20 ng/mL or greater (40%; P < .0001) and GALAD (gender, age, Lens culinaris agglutinin-reactive AFP, AFP, and des-γ-carboxy-prothrombin score) of -0.63 or greater (71%; P = .03), although AFP and GALAD at these cut-off values had higher specificities (100% and 93%, respectively). CONCLUSIONS: The mt-HBT may significantly improve early stage HCC detection for patients undergoing HCC surveillance, a critical step to increasing curative treatment opportunities and reducing mortality. ClinicalTrials.gov number NCT03628651.

Optimisation of root traits to provide enhanced ecosystem services in agricultural systems: A focus on cover crops.

Roots are the interface between the plant and the soil and play a central role in multiple ecosystem processes. With intensification of agricultural practices, rhizosphere processes are being disrupted and are causing degradation of the physical, chemical and biotic properties of soil. However, cover crops, a group of plants that provide ecosystem services, can be utilised during fallow periods or used as an intercrop to restore soil health. The effectiveness of ecosystem services provided by cover crops varies widely as very little breeding has occurred in these species. Improvement of ecosystem service performance is rarely considered as a breeding trait due to the complexities and challenges of belowground evaluation. Advancements in root phenotyping and genetic tools are critical in accelerating ecosystem service improvement in cover crops. In this study, we provide an overview of the range of belowground ecosystem services provided by cover crop roots: (1) soil structural remediation, (2) capture of soil resources and (3) maintenance of the rhizosphere and building of organic matter content. Based on the ecosystem services described, we outline current and promising phenotyping technologies and breeding strategies in cover crops that can enhance agricultural sustainability through improvement of root traits.

Engineering ß-Sheet Peptide Coassemblies for Biomaterial Applications.

Peptide coassembly, wherein at least two different peptides interact to form multicomponent nanostructures, is an attractive approach for generating functional biomaterials. Current efforts seek to design pairs of peptides, A and B, that form nanostructures (e.g., ß-sheets with ABABA-type ß-strand patterning) while resisting self-assembly (e.g., AAAAA-type or BBBBB-type ß-sheets). To confer coassembly behavior, most existing designs have been based on highly charged variants of known self-assembling peptides; like-charge repulsion limits self-assembly while opposite-charge attraction promotes coassembly. Recent analyses using solid-state NMR and coarse-grained simulations reveal that preconceived notions of structure and molecular organization are not always correct. This perspective highlights recent advances and key challenges to understanding and controlling peptide coassembly.

De novo design of peptides that coassemble into ß sheet-based nanofibrils.

Peptides' hierarchical coassembly into nanostructures enables controllable fabrication of multicomponent biomaterials. In this work, we describe a computational and experimental approach to design pairs of charge-complementary peptides that selectively coassemble into ß-sheet nanofibers when mixed together but remain unassembled when isolated separately. The key advance is a peptide coassembly design (PepCAD) algorithm that searches for pairs of coassembling peptides. Six peptide pairs are identified from a pool of ~106 candidates via the PepCAD algorithm and then subjected to DMD/PRIME20 simulations to examine their co-/self-association kinetics. The five pairs that spontaneously aggregate in kinetic simulations selectively coassemble in biophysical experiments, with four forming ß-sheet nanofibers and one forming a stable nonfibrillar aggregate. Solid-state NMR, which is applied to characterize the coassembling pairs, suggests that the in silico peptides exhibit a higher degree of structural order than the previously reported CATCH(+/−) peptides.

Single-cell RNA-seq analysis identifies unique chondrocyte subsets and reveals involvement of ferroptosis in human intervertebral disc degeneration.

OBJECTIVE: Nucleus pulposus (NP) plays a central role in disc degeneration pathogenesis, however, as a heterogeneous tissue, cell subsets in NP and their corresponding biological process in intervertebral disc degeneration (IVDD) are unreported. METHOD: Nucleus pulposus were isolated from normal control and IVDD, and then subjected to single-cell RNA sequencing (scRNA-seq). Unsupervised clustering of the cells based on the gene expression profiles using the Seurat package and passed to tSNE for clustering visualization. Rat model of disc degeneration was built to validate the pathways identified by scRNA-Seq. RESULTS: Seven chondrocyte subsets were revealed in NP based on differential gene expression, among which 4 subsets (C1-C4) were reported for the first time. Furthermore, GO and KEGG analyses discovered that ferroptosis pathways were enriched. Rat model of disc degeneration was built (n = 6/group, control vs. model) to validate the pathways identified by scRNA-Seq. Iron levels of NP were significantly higher in model group than control group (means 0.712 vs. 0.248, respectively, mg/gpro, p = 0.0026), and the levels of Heme Oxygenase 1 (HO-1) were also elevated in model group (means 14.33 vs. 5.16 IOD, respectively, p = 0.0002). However, the levels of ferritin light chain (FTL) were significantly decreased in model group compared to control group (means 26.17 vs. 9.00 FTL+ cell number, respectively, p = 0.0011). CONCLUSIONS: Novel chondrocyte subsets in nucleus pulposus were discovered through scRNA-Seq, which provided novel insight to understand the pathological change during the development of IVDD. Ferroptosis participated in disc degeneration pathogenesis and it might serve as a new target for intervening IVDD.

CATCH Peptides Coassemble into Structurally Heterogeneous ß-Sheet Nanofibers with Little Preference to ß-Strand Alignment.

Coassembling peptides offer an additional degree of freedom in the design of nanostructured biomaterials when compared to analogous self-assembling peptides. Yet, our understanding of how amino acid sequences encodes coassembled nanofiber structure is limited. Prior work on a charge-complementary pair, CATCH+ and CATCH- peptides, detected like-peptide nearest neighbors (CATCH+:CATCH+ and CATCH-:CATCH-) within coassembled ß-sheet nanofibers; these self-associated peptide pairs marked a departure from an "ideal" coassembled structure. In this work, we employ solid-state NMR, isotope-edited FTIR, and coarse-grained molecular dynamics simulations to evaluate the alignment of ß-strands within CATCH peptide nanofibers. Both experimental and computational results suggest that CATCH molecules coassemble into structurally heterogeneous nanofibers, which is consistent with our observations in another coassembling system, the King-Webb peptides. Within ß-sheet nanofibers, ß-strands were found to have nearest neighbors aligned in-register parallel, in-register antiparallel, and out-of-register. In comparison to the King-Webb peptides, CATCH nanofibers exhibit a greater degree of structural heterogeneity. By comparing the amino acid sequences of CATCH and King-Webb peptides, we can begin to unravel sequence-to-structure relationships, which may encode more precise coassembled ß-sheet nanostructures.

Attenuation of methylglyoxal-induced glycation and cellular dysfunction in wound healing by Centella cordifolia.

Current pre-clinical evidences of Centella focus on its pharmacological effects on normal wound healing but there are limited studies on the bioactivity of Centella in cellular dysfunction associated with diabetic wounds. Hence we planned to examine the potential of Centella cordifolia in inhibiting methylglyoxal (MGO)-induced extracellular matrix (ECM) glycation and promoting the related cellular functions. A Cell-ECM adhesion assay examined the ECM glycation induced by MGO. Different cell types that contribute to the healing process (fibroblasts, keratinocytes and endothelial cells) were evaluated for their ability to adhere to the glycated ECM. Methanolic extract of Centella species was prepared and partitioned to yield different solvent fractions which were further analysed by high performance liquid chromatography equipped with photodiode array detector (HPLC-PDA) method. Based on the antioxidant [2,2-diphenyl-1-picrylhydrazyl (DPPH) assay] screening, anti-glycation activity and total phenolic content (TPC) of the different Centella species and fractions, the ethyl acetate fraction of C. cordifolia was selected for further investigating its ability to inhibit MGO-induced ECM glycation and promote cellular distribution and adhesion. Out of the three Centella species (C. asiatica, C. cordifolia and C. erecta), the methanolic extract of C. cordifolia showed maximum inhibition of Advanced glycation end products (AGE) fluorescence (20.20 ± 4.69 %, 25.00 ± 3.58 % and 16.18 ± 1.40 %, respectively). Its ethyl acetate fraction was enriched with phenolic compounds (3.91 ± 0.12 mg CAE/µg fraction) and showed strong antioxidant (59.95 ± 7.18 µM TE/µg fraction) and antiglycation activities. Improvement of cells spreading and adhesion of endothelial cells, fibroblasts and keratinocytes was observed for ethyl acetate treated MGO-glycated extracellular matrix. Significant reduction in attachment capacity of EA.hy926 cells seeded on MGO-glycated fibronectin (41.2%) and attachment reduction of NIH3t3 and HaCaT cells seeded on MGO-glycated collagen (33.7% and 24.1%, respectively) were observed. Our findings demonstrate that ethyl acetate fraction of C. cordifolia was effective in attenuating MGO-induced glycation and cellular dysfunction in the in-vitro wound healing models suggesting that C. cordifolia could be a potential candidate for diabetic wound healing. It could be subjected for further isolation of new phytoconstituents having potential diabetic wound healing properties.