Disturbed glycolipid metabolism activates CXCL13-CXCR5 axis in senescent TSCs to promote heterotopic ossification.

Heterotopic ossification (HO) occurs as a common complication after injury, while its risk factor and mechanism remain unclear, which restricts the development of pharmacological treatment. Clinical research suggests that diabetes mellitus (DM) patients are prone to developing HO in the tendon, but solid evidence and mechanical research are still needed. Here, we combined the clinical samples and the DM mice model to identify that disordered glycolipid metabolism aggravates the senescence of tendon-derived stem cells (TSCs) and promotes osteogenic differentiation. Then, combining the RNA-seq results of the aging tendon, we detected the abnormally activated autocrine CXCL13-CXCR5 axis in TSCs cultured in a high fat, high glucose (HFHG) environment and also in the aged tendon. Genetic inhibition of CXCL13 successfully alleviated HO formation in DM mice, providing a potential therapeutic target for suppressing HO formation in DM patients after trauma or surgery.

Amphiphilic Rhodamine Fluorescent Probes Combined with Basal Imaging for Fine Structures of the Cell Membrane.

Confocal fluorescence imaging of fine structures of the cell membrane is important for understanding their biofunctions but is often neglected due to the lack of an effective method. Herein, we develop new amphiphilic rhodamine fluorescent probe RMGs in combination with basal imaging for this purpose. The probes show high signal-to-noise ratio and brightness and low internalization rate, making them suitable for imaging the fine substructures of the cell membrane. Using the representative probe RMG3, we not only observed the cell pseudopodia and intercellular nanotubes but also monitored the formation of migrasomes in real time. More importantly, in-depth imaging studies on more cell lines revealed for the first time that hepatocellular carcinoma cells secreted much more adherent extracellular vesicles than other cell lines, which might serve as a potential indicator of liver cells. We believe that RMGs may be useful for investigating the fine structures of the cell membrane.

Klebsiella aerogenes exacerbates colon tumorigenesis in the AOM/DSS-induced C57BL/6J mouse.

Klebsiella aerogenes (K. aerogenes, KA) is a gram-negative opportunistic pathogen from the Klebsiella species and the Enterobacteriaceae family. However, the impact of K. aerogenes on colorectal cancer (CRC) remains uncertain. A colitis-associated tumorigenesis animal model was established by administering azoxymethane (AOM) and dextran sulfate sodium (DSS) to C57BL/6J mice. The concentration of K. aerogenes gavage in mice was 109 cfu. The study measured the following parameters: tumor formation (number and size), intestinal permeability (MUC2, ZO-1, and Occludin), colonic inflammation (TNF-α, IL-1ß, IL-6, and IL-10), proliferation and the fluctuation of the intestinal flora. Under the AOM/DSS-treated setting, K. aerogenes colonization worsened colitis by exacerbating intestinal inflammatory reaction and destroying the mucosal barrier. The intervention markedly augmented the quantity and dimensions of neoplasm in the AOM/DSS mice, stimulated cellular growth, and impeded cellular programmed cell death. In addition, K. aerogenes exacerbated the imbalance of the intestinal microbiota by elevating the abundance of Pseudomonas, Erysipelatoclostridium, Turicibacter, Rikenella, and Muribaculum and leading to a reduction in the abundance of Odoribacter, Alloprevotella, Roseburia, and Lachnospiraceae_NK4A136_group. The presence of K. aerogenes in AOM/DSS-treated mice promoted tumorigenesis, worsened intestinal inflammation, disrupted the intestinal barrier, and caused disturbance to the gut microbiota.

FTO overexpression expedites wound healing and alleviates depression in burn rats through facilitating keratinocyte migration and angiogenesis via mediating TFPI-2 demethylation.

Burn injury is a serious traumatic injury that leads to severe physical and psychosocial impairment. Wound healing after burn injury is a substantial challenge in medical community. This study investigated the biological effects of the demethylase fat mass and obesity-associated protein (FTO) on burn injury. FTO protein level in burn skin tissues of patients was measured with Western blot assay. Keratinocytes (HaCaT cells) were given heat stimulation to induce an in vitro burn injury model, and then transfected with overexpression plasmids of FTO (pcDNA-FTO) or small interfering RNA against FTO (si-FTO). Cell proliferation, migration, and angiogenesis in keratinocytes were evaluated with CCK-8, Transwell, and tube formation assays, respectively. Tissue factor pathway inhibitor-2 (TFPI-2) m6A methylation level was detected with MeRIP­qPCR assay. Then rescue experiments were conducted to explore the effects of FTO/TFPI-2 axis on keratinocyte functions. Lentivirus carrying FTO overexpression plasmids was injected into a burn rat model to detect its effects on wound healing and depressive-like behaviors in burn rats. FTO was downregulated in burn skin and heat-stimulated keratinocytes. FTO prominently augmented proliferation, migration and angiogenesis in heat-stimulated keratinocytes, while FTO knockdown showed the opposite results. FTO inhibited TFPI-2 expression by FTO-mediated m6A methylation modification. TFPI-2 overexpression abrogated FTO mediated enhancement of proliferation, migration and angiogenesis in keratinocytes. Additionally, FTO overexpression accelerated wound healing and improved depressive-like behaviors in burn rat model. FTO prominently augmented proliferation, migration and angiogenesis in heat-stimulated keratinocytes though inhibiting TFPI-2, and then improved wound healing and depressive-like behaviors.

Properties and functions of acylated starch with short-chain fatty acids: a comprehensive review.

Short-chain fatty acids (SCFAs) are the primary energy source of colonic epithelial cells, but oral SCFAs are digested, absorbed, or degraded before reaching the colon. The acylated starch with SCFAs can be fermented and release specific SCFAs under the action of colonic intestinal microbiota. This review first introduces the preparation method, reaction mechanism, and substitution factors. Second, the structure, physical and chemical properties, in vitro function, and mechanism of acylated starch were expounded. Finally, the application of acylated starch in foods is introduced, and its safety is evaluated, providing a basis for the further development of acylated starch-based foods. The acylated starch obtained by different acylation types and preparation methods is different in particle, molecular, and crystal structures, leading to changes in the function and physicochemical properties. Meanwhile, acylated starch has the functional potential of targeted delivery of SCFAs to the colon, which can increase SCFAs in feces and intestine, selectively regulate the intestinal microbiota, and produce a prebiotic effect conducive to host health. The safety of acetylated starch has been supported by relevant studies, which have been widely used in various food fields and have great potential in the food industry.

The protective role of RACK1 in hepatic ischemia‒reperfusion injury-induced ferroptosis.

Although ferroptosis plays a crucial role in hepatic ischemia‒reperfusion injury (IRI), the molecular mechanisms underlying this process remain unclear. We aimed to explore the potential involvement of the receptor for activated C kinase 1 (RACK1) in hepatic IRI-triggered ferroptosis. Using hepatocyte-specific RACK1 knockout mice and alpha mouse liver 12 (AML12) cells, we conducted a series of in vivo and in vitro experiments. We found that RACK1 has a protective effect on hepatic IRI-induced ferroptosis. Specifically, RACK1 was found to interact with AMPKα through its 1-93 amino acid (aa) region, which facilitates the phosphorylation of AMPKα at threonine 172 (Thr172), ultimately exerting an antiferroptotic effect. Furthermore, the long noncoding RNA (lncRNA) ZNFX1 Antisense 1 (ZFAS1) directly binds to aa 181-317 of RACK1. ZFAS1 has a dual impact on RACK1 by promoting its ubiquitin‒proteasome-mediated degradation and inhibiting its expression at the transcriptional level, which indirectly exacerbates hepatic IRI-induced ferroptosis. These findings underscore the protective role of RACK1 in hepatic IRI-induced ferroptosis and showcase its potential as a prophylactic target for hepatic IRI mitigation.

Comparing perioperative outcomes between regional anesthesia and general anesthesia in patients undergoing hip fracture surgery: a systematic review and meta-analysis.

PURPOSE: Nearly all patients with hip fractures undergo surgical treatment. The use of different anesthesia techniques during surgery may influence the clinical outcomes. The optimal anesthetic technique for patients undergoing hip fracture surgery is still controversial. We performed this updated systematic review and meta-analysis to compare clinical outcomes of patients undergoing hip fracture surgery with different anesthesia techniques. SOURCE: Articles published from 2000 to May 2023 were included from MEDLINE, Embase, Web of Science, and the Cochrane Library. We included randomized controlled trials and observational studies comparing general anesthesia (GA) with regional anesthesia (RA) for the outcomes of 30-day mortality, 90-day mortality, in-hospital mortality, perioperative complications, length of hospital stay, and length of surgery in patients undergoing hip fracture surgery. Subgroup analyses were performed for the outcomes based on study design (randomized controlled trials or observational studies). We used a random-effects model for all analyses. PRINCIPAL FINDINGS: In this meta-analysis, we included 12 randomized controlled trials. There was no difference in postoperative 30-day mortality between the two groups (odds ratio [OR], 0.88; 95% confidence interval [CI], 0.44 to 1.74; I2 = 0%). The incidence of intraoperative hypotension was lower in patients who received RA vs GA (OR, 0.52; 95% CI, 0.38 to 0.72; I2 = 0%). No significant differences were observed in 90-day mortality, in-hospital mortality, postoperative delirium, pneumonia, myocardial infarction, venous thromboembolism, length of surgery, and length of hospital stay. CONCLUSION: In this updated systematic review and meta-analysis, RA did not reduce postoperative 30-day mortality in hip fracture surgery patients compared to GA. Fewer patients receiving RA had intraoperative hypotension than those receiving GA did. Apart from intraoperative hypotension, the data showed no differences in complications between the two anesthetic techniques. STUDY REGISTRATION: PROSPERO (CRD42023411854); registered 7 April 2023.

RéSUMé: OBJECTIF: Presque toutes les personnes ayant subi une fracture de la hanche se font opérer. L'utilisation de différentes techniques d'anesthésie pendant la chirurgie peut influencer les issues cliniques. La technique d'anesthésie optimale pour la patientèle bénéficiant de chirurgie de fracture de la hanche est encore controversée. Nous avons réalisé cette mise à jour par revue systématique et méta-analyse pour comparer les issues cliniques des personnes bénéficiant d'une chirurgie de fracture de la hanche avec différentes techniques d'anesthésie. SOURCES: Les articles publiés de 2000 à mai 2023 ont été inclus à partir des bases de données MEDLINE, Embase, Web of Science et Cochrane Library. Nous avons inclus des études randomisées contrôlées et des études observationnelles comparant l'anesthésie générale (AG) à l'anesthésie régionale (AR) pour les issues de mortalité à 30 jours, de mortalité à 90 jours, de mortalité intrahospitalière, de complications périopératoires, de durée de séjour à l'hôpital et de durée de la chirurgie pour les personnes bénéficiant d'une chirurgie de fracture de la hanche. Des analyses de sous-groupes ont été réalisées pour les issues en fonction de la méthodologie utilisée (étude randomisée contrôlée ou étude observationnelle). Un modèle à effets aléatoires a été utilisé pour toutes les analyses. CONSTATATIONS PRINCIPALES: Dans cette méta-analyse, nous avons inclus 12 études randomisées contrôlées. Il n'y avait pas de différence dans la mortalité postopératoire à 30 jours entre les deux groupes (rapport de cotes [RC], 0,88; intervalle de confiance à 95 % [IC], 0,44 à 1,74; I2 = 0 %). L'incidence d'hypotension peropératoire était plus faible chez les patient·es ayant reçu une AR vs une AG (RC, 0,52; IC 95 %, 0,38 à 0,72; I2 = 0 %). Aucune différence significative n'a été observée dans les issues de mortalité à 90 jours, de mortalité intrahospitalière, de delirium postopératoire, de pneumonie, d'infarctus du myocarde, de thromboembolie veineuse, de durée de la chirurgie, et de durée du séjour à l'hôpital. CONCLUSION: Dans cette revue systématique avec méta-analyse, l'anesthésie régionale n'a pas réduit la mortalité postopératoire à 30 jours chez les personnes ayant bénéficié d'une chirurgie de fracture de la hanche par rapport à l'anesthésie générale. Une proportion moindre de patient·es ayant reçu une AR présentaient une hypotension peropératoire par rapport aux personnes ayant reçu une AG. En dehors de l'hypotension peropératoire, les données n'ont montré aucune différence dans les complications entre les deux techniques anesthésiques. ENREGISTREMENT DE L'éTUDE: PROSPERO (CRD42023411854); enregistrée le 7 avril 2023.

Sagittal morphometry of intervertebral spaces in subaxial cervical region of asymptomatic Chinese.

PURPOSE: This study aimed to quantify and evaluate morphology of intervertebral space between neighboring cervical units using radiographic imaging indices, to help spine surgeons when performing anterior cervical discectomy and fusion (ACDF) surgery on the Chinese population. METHODS: The background and imaging parameters of the subjects were assessed. Cervical lateral radiographs were employed to measure the intervertebral height (IH), intervertebral height index (IHI), and segmental lordosis (SL). Endplate parameters measurements were conducted on sagittal T2-weighted magnetic resonance imaging (MRI), including endplate sagittal diameter (ESD), and endplate concavity depth (ECD). All individuals were divided into three age groups: individuals aged 20-35 were in group A, individuals aged 36-50 were in group B, and individuals aged over 50 were in group C. A comparison of the variables was conducted among the three groups. Additionally, these radiographic parameters were also compared between males and females. RESULTS: A total of 102 individuals were included in this study. IH was greater at C6/7 than those at other segmental levels (p < 0.001). The largest SL values were found at C6/7, while the least were found at C3/4. The superior ESD (ESDs) and ECD (ECDs) of the intervertebral space were significantly greater than those of the inferior endplates (p < 0.05). The ESD and ECD values were the largest at C6/7, while the least at C3/4. Additionally, age and gender had an influence on several parameters. IH was significantly lower in group A compared to group B (p < 0.05) and group C (p < 0.05) from C3/4 level to C6/7 level. ECDs were lower in group A compared to group B (p < 0.05) and group C (p < 0.05) at each level. IH and ESD in males were generally significantly greater than those in females at all levels (p < 0.05). CONCLUSION: The current study found that C6/7 had the greatest IH, SL, ESD, and ECD values in asymptomatic Chinese. SL gradually increased from C3/4 to C6/7 levels. IH and ECD were significantly associated with age. Males had greater IH and ESD values than females. These findings provide baseline information for planning for selection of anterior screws and intervertebral implants.

Maslinic acid alleviates intervertebral disc degeneration by inhibiting the PI3K/AKT and NF-κB signaling pathways.

Intervertebral disc degeneration (IDD) is the cause of low back pain (LBP), and recent research has suggested that inflammatory cytokines play a significant role in this process. Maslinic acid (MA), a natural compound found in olive plants ( Olea europaea), has anti-inflammatory properties, but its potential for treating IDD is unclear. The current study aims to investigate the effects of MA on TNFα-induced IDD in vitro and in other in vivo models. Our findings suggest that MA ameliorates the imbalance of the extracellular matrix (ECM) and mitigates senescence by upregulating aggrecan and collagen II levels as well as downregulating MMP and ADAMTS levels in nucleus pulposus cells (NPCs). It can also impede the progression of IDD in rats. We further find that MA significantly affects the PI3K/AKT and NF-κB pathways in TNFα-induced NPCs determined by RNA-seq and experimental verification, while the AKT agonist Sc-79 eliminates these signaling cascades. Furthermore, molecular docking simulation shows that MA directly binds to PI3K. Dysfunction of the PI3K/AKT pathway and ECM metabolism has also been confirmed in clinical specimens of degenerated nucleus pulposus. This study demonstrates that MA may hold promise as a therapeutic agent for alleviating ECM metabolism disorders and senescence to treat IDD.

The Cytotoxic Activity and Metabolic Profiling of Hyptis rhomboidea Mart. et Gal.

Many naturally occurring chemical metabolites with significant cytotoxic activities have been isolated from medicinal plants and have become the leading hotspot of anti-cancer research in recent years. Hyptis rhomboidea Mart. et Gal is used as a folk medicine in South China to treat or assist in the treatment of liver disease, ulcers, and edema. But its chemical constituents have not been fully investigated yet. This study aimed to assess the cytotoxicity of H. rhomboidea, which was chemically characterized by chromatography-mass spectrometry methods. The results showed that the 95% ethanol extract of H. rhomboidea has marked inhibitory effects on five human cancer cell lines (HL-60, A549, SMMC-7721, MDA-MB-231, and SW480), with IC50 values ranging from 15.8 to 40.0 µg/mL. A total of 64 compounds were identified by ultra-high-performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) and gas chromatograph-mass spectroscopy (GC-MS) analysis of H. rhomboidea crude extract. Among them, kaempferol, quercetin, rosmarinic acid, squalene, and campesterol were found to be abundant and might be the major metabolites involved to its bioactivity. The cytotoxic characterization and metabolite profiling of H. rhomboidea displayed in this research provides scientific evidence to support its use as medicinal properties.

Electronic Excitation Characteristics and Spectral Behavior of Phosphate Anions.

Absorption spectra are fundamental bases for the qualitative and quantitative analysis of the target chemical, and the development of an analytical model can be improved by studying its characteristics and rules. In the present study, the electronic excitation characteristics of phosphate anions (H2PO4-, HPO42-, and PO43-) were analyzed based on the charge-transfer spectrum. In addition, the absorption spectra of phosphate anions at the energy level of PBE0/6-311+G (d,p) were recorded based on the time-dependent density functional theory (TD-DFT) method. Different (HPO42-)n·(H2O)10-n molecular clusters were theoretically constructed, and the combined TD-DFT method and independent gradient model revealed that red shift of the maximum absorption wavelength (λmax) with the increase of phosphate anion concentration (0-10 mM) may be caused by the decrease of hydrogen bond interaction. In addition, the prominent dispersion in the short-wave region mainly resulted in the red shift of λmax with the increase in optical path length (1-100 mm). Moreover, with the increase in spectral bandwidth (0.4-3.0 nm), λmax slightly blue-shifted because of the increase in energy through the slit, and repeatability of the corresponding absorbance measurement at λmax gradually improved. As the spectral bandwidth increased, light monochromaticity became poor, resulting in the decrease of the linearly fitted correlation coefficient of the concentration-absorbance curve. Finally, the multivariate analysis of variance results showed that the optical path length was the most significant factor that influenced the absorption spectral characteristics of phosphate anions. This study provides a basis for the qualitative and quantitative analysis of phosphate anions by using absorption spectra and also renders a theoretical reference for absorption spectroscopy of other chemicals.

Identifying the key genes regulating mesenchymal stem cells chondrogenic differentiation: an in vitro study.

BACKGROUND: Mesenchymal stem cells (MSCs) possess the potential to differentiate into chondrocytes, which makes them an ideal source for healing cartilage defects. Here, we seek to identify the essential genes participating in MSCs chondrogenesis. METHODS: Human MSCs were induced for chondrogenesis for 7, 14, and 21 days using a high-density micromass culture system, and RNA was extracted for RNA-seq. RESULTS: A total of 6247 differentially expressed genes (DEGs) were identified on day 7, and 85 DEGs were identified on day 14. However, no significant DEGs was identified on day 21. The top 30 DEGs at day 7, including COL9A3, COL10A1, and CILP2, are closely related to extracellular matrix organization. While the top 30 DEGs at day 14 revealed that inflammation-related genes were enriched, including CXCL8, TLR2, and CCL20. We also conducted protein-protein interaction (PPI) networks analysis using the search tool for the retrieval of interacting genes (STRING) database and identified key hub genes, including CXCL8, TLR2, CCL20, and MMP3. The transcriptional factors were also analyzed, identifying the top 5 TFs: LEF1, FOXO1, RORA, BHLHE41, and SOX5. We demonstrated one particular TF, RORA, in promoting early MSCs chondrogenesis. CONCLUSIONS: Taken together, our results suggested that these DEGs may have a complex effect on MSCs chondrogenesis both synergistically and solitarily.

Comparison of anterior or posterior approach in surgical treatment of thoracic and lumbar tuberculosis: a retrospective case-control study.

BACKGROUND: With the widespread use of the posterior surgery, more and more surgeons chose posterior surgery to treat thoracic and lumbar tuberculosis. But others still believed that the anterior surgery is more conducive to eradicating the lesions, and easier to place larger bone pieces for bone graft fusion. We compared the clinical and radiological outcomes of anterior and posterior surgical approaches and presented our views. METHODS: This study included 52 thoracic and lumbar tuberculosis patients at Sun Yat-sen Memorial Hospital from January 2010 to June 2018. All cases underwent radical debridement, nerve decompression, intervertebral bone graft fusion and internal fixation. Cases were divided into anterior group (24 cases) and posterior group (28 cases). Statistical analysis was used to compare the clinical effectiveness, radiological outcomes, complications and other related information. RESULTS: Patients in the anterior group and the posterior group were followed up for an average of 27.4 and 22.3 months, respectively. There were no statistically significant differences between groups in the preoperative, postoperative and last follow-up VAS score, ASIA grade and Cobb angle of local kyphosis. Moreover, there were no statistically significant differences in the improvement of neurological function, loss of kyphotic correction, total incidence of complications, operative time, intraoperative blood loss and hospital stay between the two groups (P > 0.05). But there was greater correction of kyphosis, earlier bone fusion, lower incidence of poor wound healing, less interference with the normal spine and less internal fixation consumables and medical cost in the anterior group (P < 0.05). CONCLUSIONS: Both anterior and posterior approaches are feasible for thoracic and lumbar tuberculosis. While for thoracic and lumbar tuberculosis patients with a single lesion limited in the anterior and middle columns of the spine without severe kyphosis, the anterior approach surgery may have greater advantages in kyphosis correction, bone fusion, wound healing, protection of the normal spine, and medical consumables and cost.

MET promotes the proliferation and differentiation of myoblasts.

The receptor tyrosine kinase MET plays a vital role in skeletal muscle development and in postnatal muscle regeneration. However, the effect of MET on myogenesis of myoblasts has not yet been fully understood. This study aimed to investigate the effects of MET on myogenesis in vivo and in vitro. Decreased myonuclei and down-regulated expression of myogenesis-related markers were observed in Met p.Y1232C mutant heterozygous mice. To explore the effects of MET on myoblast proliferation and differentiation, Met was overexpressed or interfered in C2C12 myoblast cells through the lentiviral transfection. The Met overexpression cells exhibited promotion in myoblast proliferation, while the Met deficiency cells showed impediment in proliferation. Moreover, myoblast differentiation was enhanced by the stable Met overexpression, but was impaired by Met deficiency. Furthermore, this study demonstrated that SU11274, an inhibitor of MET kinase activity, suppressed myoblast differentiation, suggesting that MET regulated the expression of myogenic regulatory factors (MRFs) and of desmin through the classical tyrosine kinase pathway. On the basis of the above findings, our work confirmed that MET promoted the proliferation and differentiation of myoblasts, deepening our understanding of the molecular mechanisms underlying muscle development.

Inverse Agonist of Retinoid-Related Orphan Receptor-Alpha Prevents Apoptosis and Degeneration in Nucleus Pulposus Cells via Upregulation of YAP.

Intervertebral disc degenerative disease (IDD) is the most common degenerative spine disease, which leads to chronic low back pain and symptoms in the lower extremities. In this study, we found that RORα, a member of the retinoid-related orphan receptor family, is significantly elevated in nucleus pulposus tissue in IDD patients. The elevation of RORα is associated with increased apoptosis of nucleus pulposus (NP) cells. Therefore, we applicated a well-established inverse agonist of RORα, SR3335, to investigate its role in regulating NP cell metabolism and apoptosis. To further investigate the mechanism that SR3335 regulates the pathogenesis of IDD in vitro, tumor necrosis factor alpha (TNF-α) stimulation was used in human NP cells to mimic the hostile environment that leads to degeneration. We found that SR3335 treatment reversed the trend of increased apoptosis in NP cells induced by TNF-α treatment. Next, TNF-α treatment upregulated the expression of type II collagen and aggrecan and downregulated MMP13 (matrix-degrading enzyme matrix metalloproteinase 13) and ADAMTS4 (a disintegrin and metalloproteinase with thrombospondin motifs 4). However, these effects were reversed after SR3335 treatment. Furthermore, we find that SR3335 mediated the effect in NP cells by regulating the YAP signaling pathway, especially by affecting the phosphorylation state of YAP. In conclusion, the reduction of matrix degradation enzymes and apoptosis upon SR3335 treatment suggests that SR3335 is a promising drug in reversing the deleterious microenvironment in IDD patients.

Glutathione-functionalized two-dimensional cobalt sulfide nanosheets for rapid and highly efficient enrichment of N-glycopeptides.

Protein glycosylation plays pivotal role in a variety of biological processes and has association with many diseases. The highly efficient glycopeptide enrichment is essential for the mass spectrometry-based glycoproteome research to reduce interference from non-glycopeptides. In this study, novel glutathione-functionalized two-dimensional cobalt sulfide nanosheets (Co-S@Au-GSH) were synthesized for rapid and highly effective enrichment of glycopeptides. By using this nanomaterial, 34 and 21 N-glycopeptides were effectively captured from human serum immunoglobulin G (IgG) and horseradish peroxidase (HRP) digests, respectively. In addition, the Co-S@Au-GSH showed remarkable performance in N-glycopeptide extraction with high selectivity (HRP: BSA = 1:500), low limit of detection (0.5 fmol/µL), high binding capacity (150 mg/g), good reusability, and great robustness. Moreover, it was successfully applied in complex serum samples, demonstrating its excellent enrichment performance. These results indicated that this nanomaterial has great potential in complicated practice samples in glycoproteome determination.

A modified method to treat severe asymptomatic pre-existing degeneration of adjacent segment: a retrospective case-control study.

BACKGROUND: Pre-existing degeneration of adjacent segment is an important risk factor for adjacent-segment degeneration (ASD), but only limited and controversial studies have addressed its management. METHODS: We retrospectively analyzed patients with symptomatic degeneration of the L5/S1 segment warranting surgical interference and severe asymptomatic degeneration of the L4/5 segment. Of these patients, those who underwent interbody fusion of the causative (L5/S1) segment and distraction of the intervertebral space and facet fusion of the adjacent L4/5 segment were included in Group A (n = 103), while those who underwent interbody fusion of both the L5/S1 and L4/5 segments were included in Group B (n = 81). Clinical and radiographic outcomes were evaluated. RESULTS: Mean follow-up time was 58.5 months (range, 48-75 months). We found no significant difference in clinical outcomes or incidence of ASD in the L3/4 segment between Groups A and B. Compared with Group B, Group A experienced less bleeding (315 ± 84 ml vs. 532 ± 105 ml), shorter operation time (107 ± 34 min vs. 158 ± 55 min) and lower costs (US $13,830 ± $2640 vs. US $16,020 ± $3380; P < 0.05). In Group A, the disc height ratio (DHR) of the L4/5 segment was significantly increased from a preoperative value of 0.40 ± 0.13 to a last-follow-up value of 0.53 ± 0.18 (P < 0.05), while the degree of canal stenosis (DCS) was decreased from a preoperative value of 34.3 ± 11.2% to a last-follow-up value of 15.9 ± 9.3 % (P < 0.05). CONCLUSIONS: This modified method could be effective in treating severe asymptomatic pre-existing degeneration of adjacent segment in the lumbar spine.

Observation of the Elevation of Cholinesterase Activity in Brain Glioma by a Near-Infrared Emission Chemsensor.

The excessive expression of cholinesterases (ChEs) directly disturbs the metabolism of acetylcholine (ACh), causing disordering neurotransmission in the brain or even Alzheimer's disease and cancer. However, the variation of ChEs including acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) in brain glioma has not yet been investigated. Therefore, the development of a suitable method for in situ imaging ChEs in brain tissues to understand the physiological functions of ChEs in depth is very important. Herein, a new near-infrared emission fluorescent probe (IPAN) for visualization of ChE activity was developed. IPAN exhibits ultrafast response to ChEs, low detection limit for AChE (0.127 U/mL) and BChE (0.0117 U/mL), and a large Stokes shift with near-infrared emission. Based on these excellent attributes, the IPAN was effectively utilized for imaging the fluctuations of ChE activity in the apoptosis cells and zebrafish. Notably, by utilizing the unique probe IPAN, we observed a significant enhancement of ChE activity in the tumor cells and brain glioma, for the first time. We believe that this interesting finding could provide a powerful guidance for tumor resection in the future.

Characterization and directed evolution of propionyl-CoA carboxylase and its application in succinate biosynthetic pathway with two CO2 fixation reactions.

Propionyl-CoA carboxylase (PCC) is a promising enzyme in the fields of biological CO2 utilization, synthesis of natrual products, and so on. The activity and substrate specificity of PCC are dependent on its key subunit carboxyltransferase (CT). To obtain PCC with high enzyme activity, seven pccB genes encoding CT subunit from diverse microorganisms were expressed in recombinant E. coli, and PccB from Bacillus subtilis showed the highest activity in vitro. To further optimize this protein using directed evolution, a genetic screening system based on oxaloacetate availability was designed to enrich the active variants of PccBBs. Four amino acid substitutions (D46G, L97Q, N220I and I391T) proved of great assistance in PccBBs activity improvement, and a double mutant of PccBBs (N220I/I391T) showed a 94-fold increase of overall catalytic efficiency indicated by kcat/Km. Moreover, this PccBBs double mutant was applied in construction of new succinate biosynthetic pathway. This new pathway produces succinate from acetyl-CoA with fixation of two CO2 molecules, which was confirmed by isotope labeling experiment with NaH13CO3. Compared with previous succinate production based on carboxylation of phosphoenolpyruvate or pyruvate, this new pathway showed some advantages including higher CO2 fixation potentiality and availability under aerobic conditions. In summary, this study developed a PCC with high enzyme activity which can be widely used in biotechnology field, and also demonstrated the feasibility of new succinate biosynthetic pathway with two CO2 fixation reactions.

A ratiometric fluorescent probe for reversible monitoring of endogenous SO2/formaldehyde in cytoplasm and nucleoli regions and its applications in living mice.

The excessive production of sulfur dioxide (SO2) and formaldehyde (FA) by organisms is closely associated with several diseases, including neurological disorders, respiratory disease, and genotoxicity. RNA plays a central role in the expression of genes. However, it is difficult for fluorescent probes to explore the intersecting correlation of SO2 and FA near the nucleolus regions due to the protective obstacle of the cell nucleus membrane. Herein, a unique fluorescent probe (DP) for reversible detection of the interaction of SO2 and FA in the nucleolus regions was constructed. In light of the outstanding attributes of DP, including a large fluorescence ratio variation, ultrafast detection of SO2, and excellent reversibility, it was successfully employed to track the variation of endogenous SO2 and FA in the cytoplasm and nucleolus regions of live cells. In addition, the DP probe could be applied to the imaging of endogenous SO2 and then recovered by FA in live mice.