A novel score for early prediction of urinary tract infection risk in patients with acute ischemic stroke: a nomogram-based retrospective cohort study.

This study aimed to construct and externally validate a user-friendly nomogram-based scoring model for predicting the risk of urinary tract infections (UTIs) in patients with acute ischemic stroke (AIS). A retrospective real-world cohort study was conducted on 1748 consecutive hospitalized patients with AIS. Out of these patients, a total of 1132 participants were ultimately included in the final analysis, with 817 used for model construction and 315 utilized for external validation. Multivariate regression analysis was applied to develop the model. The discriminative capacity, calibration ability, and clinical effectiveness of the model were evaluated. The overall incidence of UTIs was 8.13% (92/1132), with Escherichia coli being the most prevalent causative pathogen in patients with AIS. After multivariable analysis, advanced age, female gender, National Institute of Health Stroke Scale (NIHSS) score ≥ 5, and use of urinary catheters were identified as independent risk factors for UTIs. A nomogram-based SUNA model was constructed using these four factors (Area under the receiver operating characteristic curve (AUC) = 0.810), which showed good discrimination (AUC = 0.788), calibration, and clinical utility in the external validation cohort. Based on four simple and readily available factors, we derived and externally validated a novel and user-friendly nomogram-based scoring model (SUNA score) to predict the risk of UTIs in patients with AIS. The model has a good predictive value and provides valuable information for timely intervention in patients with AIS to reduce the occurrence of UTIs.

Postpartum choriocarcinoma - a rare cause of delayed postpartum hemorrhage: Four case reports and literature review.

BACKGROUND: Delayed postpartum hemorrhage is rare, with an incidence of 0.5% to 2.0% in all pregnancies. The most important causes are placental remnants, infections, and placental bed subinvolution. Postpartum choriocarcinoma, a highly malignant complication of pregnancy, is a rare condition that can be easily misdiagnosed as other common causes, such as gestational remnants, and delays the diagnosis. METHODS: Four patients visited our clinic complaining of delayed postpartum hemorrhage, combined with respiratory and neurological symptoms in 2 cases. Two cases were confirmed by histopathological examination and in addition, medical history, elevated human chorionic gonadotropin (hCG) level, and imaging findings help confirm the diagnosis of delayed postpartum hemorrhage caused by postpartum choriocarcinoma in other cases. Individualized combination chemotherapies were prescribed. In the light of massive cerebral metastasis in case 2, intrathecal methotrexate injection combined with whole-brain radiotherapy was prescribed. RESULTS: Due to the absence of routine monitoring of ß-hCG following full-term delivery, there was widespread metastasis at the time of diagnosis. Three patients got complete remission and there is no sign of recurrence. One patient had relapse and widespread metastasis and died at home 6 months after the last chemotherapy. CONCLUSION: It is important to be aware of the possibility of choriocarcinoma in patients with delayed postpartum hemorrhage. Clinicians should improve the recognition of choriocarcinoma following full-term delivery, emphasize the monitoring of ß-hCG, comprehensively analyze the general condition of patients, and conduct standardized and individualized chemotherapy protocols.

Profiling Human Cerebrospinal Fluid (CSF) Endogenous Peptidome in Alzheimer's Disease.

Human cerebrospinal fluid (CSF) is a rich source for central nervous system (CNS)-related disease biomarker discovery due to its direct interchange with the extracellular fluid of the CNS. Though extensive proteome-level profiling has been conducted for CSF, studies targeting at its endogenous peptidome is still limited. It is more difficult to include the post-translational modifications (PTMs) characterization of the peptidome in the mass spectrometry (MS) analysis because of their low abundance and the challenge of data interpretation. In this chapter, we present a peptidomic workflow that combines molecular weight cut-off (MWCO) separation, electron-transfer and higher-energy collision dissociation (EThcD) fragmentation, and a three-step database searching strategy for comprehensive PTM analysis of endogenous peptides including both N-glycosylation and O-glycosylation and other common peptide PTMs. The method has been successfully adopted to analyze CSF samples from healthy donors, mild cognitive impairment (MCI), and Alzheimer's disease (AD) patients to provide a landscape of peptidome in different disease states.

Characteristics of germline DNA damage response gene mutations in ovarian cancer in Southwest China.

DNA damage response (DDR) pathways are responsible for repairing endogenous or exogenous DNA damage to maintain the stability of the cellular genome, including homologous recombination repair (HRR) pathway, mismatch repair (MMR) pathway, etc. In ovarian cancer, current studies are focused on HRR genes, especially BRCA1/2, and the results show regional and population differences. To characterize germline mutations in DDR genes in ovarian cancer in Southwest China, 432 unselected ovarian cancer patients underwent multi-gene panel testing from October 2016 to October 2020. Overall, deleterious germline mutations in DDR genes were detected in 346 patients (80.1%), and in BRCA1/2 were detected in 126 patients (29.2%). The prevalence of deleterious germline mutations in BRCA2 is higher than in other studies (patients are mainly from Eastern China), and so is the mismatch repair genes. We identified three novel BRCA1/2 mutations, two of which probably deleterious (BRCA1 p.K1622* and BRCA2 p.L2987P). Furthermore, we pointed out that deleterious mutations of FNACD2 and RECQL4 are potential ovarian cancer susceptibility genes and may predispose carriers to ovarian cancer. In conclusion, our study highlights the necessity of comprehensive germline mutation detection of DNA damage response genes in ovarian cancer patients, which is conducive to patient management and genetic counseling.

Decoding Molecular Mechanism Underlying Human Olfactory Receptor OR8D1 Activation by Sotolone Enantiomers.

Sotolone, a chiral compound, plays an important role in the food industry. Herein, (R)-/(S)-sotolone were separated to determine their odor characteristics and thresholds in air (R-form: smoky, burned, herb, and green aroma, 0.0514 µg/m3; S-form: sweet, milk, acid, and nutty aroma, 0.0048 µg/m3). OR8D1 responses to (R)-/(S)-sotolone were detected in a HEK293 cell-based luminescence assay. (S)-Sotolone was a more potent agonist than (R)-sotolone (EC50 values of 84.98 ± 1.05 and 167.20 ± 0.25 µmol/L, respectively). Molecular dynamics simulations and molecular mechanics Poisson-Boltzmann surface area analyses confirmed that the combination of (S)-sotolone and OR8D1 was more stable than that of (R)-sotolone. Odorant docking, multiple sequence alignments, site-directed mutagenesis, and functional studies with recombinant odorant receptors (ORs) in a cell-based luminescence assay identified 11 amino-acid residues that influence the enantioselectivity of OR8D1 toward sotolone significantly and that N2065.46 was indispensable to the activation of OR8D1 by (S)-sotolone.

PARP inhibitor maintenance treatment for newly diagnosed ovarian cancer patients: a real-world study from China.

Purpose: This study evaluated the efficacy and safety in a real-world population of epithelial ovarian cancer (EOC) treated with poly (ADP-ribose) polymerase inhibitor (PARPi) as first-line maintenance therapy in the largest gynecologic oncology center in Western China. Methods: This study included patients newly diagnosed EOC who received PARPi as first-line maintenance therapy in West China Second University Hospital from August 1, 2018 to September 31, 2022. The primary endpoints were progression-free survival (PFS) and safety evaluated by Common Terminology Criteria for Adverse Events Version 5.0(CTCAE 5.0). The secondary endpoints were overall survival (OS) and prognostic factors influencing the PFS of patients in real world. Results: Among the eligible 164 patients, 104 patients received olaparib and 60 patients received niraparib. 100 patients (61.0%) had mutations in breast cancer susceptibility gene (BRCA). 87 patients (53.0%) received primary debulking surgery (PDS) while 77 patients (47.0%) received interval debulking surgery (IDS). 94 patients (94/164, 57.3%) achieved R0 and 39 patients (23.8%) achieved R1 after PDS/IDS. 112 (68.3%) achieved complete response (CR) after first-line chemotherapy, while 49 (29.9%) achieved partial response (PR). The median follow-up time was 17.0 months (95% CI 15.6-18.4), and the median PFS has not been reached yet. Multivariate analysis demonstrated that BRCA mutations and CR/PR after platinum-based chemotherapy were independent factors associated with prolonged PFS. Hematologic toxicity was the most common grade≥3 AE. There were no incidence of myelodysplastic syndromes/acute myelogenous leukemia (MDS/AML). Conclusion: Focusing on PARPi as first-line maintenance therapy for patients with EOC, this study represented the largest single-center real-world study in China to date. Two independent factors were identified to prolong the PFS of patients: BRCA mutated type and CR/PR after primary treatment, which should be further confirmed with long-term follow-up and large sample sizes.

Construction and evaluation of a cloud follow-up platform for gynecological patients receiving chemotherapy.

BACKGROUND: Patient follow-up is an essential component of hospital management. In the current information era, the patient follow-up scheme is expected to be replaced by Internet technology. This study constructed a cloud follow-up platform for gynecological chemotherapy patients and assessed its cost-effectiveness and patients' feedback. METHODS: A total of 2,538 patients were followed up using a cloud follow-up system between January and October 2021. Prior to this, 690 patients were followed manually via telephone calls. Patients' characteristics, follow-up rate, satisfaction, and session duration were compared between the cloud follow-up and manual follow-up groups. In addition, the read rate of health education materials in the cloud follow-up group was analyzed. RESULTS: General information, including age, education attainment, cancer stage, and disease category, and follow-up rate (cloud: 6,957/7,614, 91.4%; manual: 1,869/2,070, 90.3%; P = 0.13) did not significantly differ between the two groups. The follow-up satisfaction of the cloud follow-up patients was significantly better than that of the manual follow-up group (cloud: 7,192/7,614, 94.5%; manual: 1,532/2,070, 74.0%; P<0.001). The time spent on the follow-up was approximately 1.2 h for 100 patients in the cloud follow-up group and 10.5 h in the manual follow-up group. Multivariate analysis indicated that the cloud follow-up group had significantly greater follow-up satisfaction (odds ratio: 2.239, 95% CI: 1.237 ~ 5.219). Additionally, the average follow-up duration of the cloud follow-up group decreased by 9.287 h (coefficient: -9.287, 95% CI: -1.439~-0.165). The read rate of health education materials was 72.9% in the cloud follow-up group. CONCLUSIONS: The follow-up effect of the cloud follow-up group was not inferior to that of the manual follow-up group. The cloud follow-up was more effective for prevention and control requirements in the post-epidemic era. Cloud follow-up can save medical resources, improve cost-effectiveness, provide sufficient health education resources for patients, and improve their satisfaction.

Human papillomavirus E7 protein induces homologous recombination defects and PARPi sensitivity.

PURPOSE: Cervical cancer is a common gynecological malignancy, pathologically associated with persistent infection of high-risk types of human papillomavirus (HPV). Previous studies revealed that HPV-positive cervical cancer displays genomic instability; however, the underlying mechanism is not fully understood. METHODS: To investigate if DNA damage responses are aggravated in precancerous lesions of HPV-positive cervical epithelium, cervical tissues were biopsied and cryosectioned, and subjected to immunofluorescent staining. Cloned HA-tagged E6 and E7 genes of HPV16 subtype were transfected into HEK293T or C33A cells, and indirect immunofluorescent staining was applied to reveal the competency of double strand break (DSB) repair. To test the synthetic lethality of E7-indued HRD and PARP inhibitor (PARPi), we expressed E7 in C33A cells in the presence or absence of olaparib, and evaluated cell viability by colony formation. RESULTS: In precancerous lesions, endogenous DNA lesions were elevated along with the severity of CIN grade. Expressing high-risk viral factor (E7) in HPV-negative cervical cells did not impair checkpoint activation upon genotoxic insults, but affected the potential of DSB repair, leading to homologous recombination deficiency (HRD). Based on this HPV-induced genomic instability, the viability of E7-expressing cells was reduced upon exposure to PARPi in comparison with control cells. CONCLUSION: In aggregate, our findings demonstrate that HPV-E7 is a potential driver for genome instability and provides a new angle to understand its role in cancer development. The viral HRD could be employed to target HPV-positive cervical cancer via synthetic lethality.

Cotton Ti-IMAC: Developing Phosphorylated Cotton as a Novel Platform for Phosphopeptide Enrichment.

Protein phosphorylation is an important post-translational modification (PTM), which is involved in many important cellular functions. Understanding protein phosphorylation at the molecular level is critical to deciphering its relevant biological processes and signaling networks. Mass spectrometry (MS) has become a powerful tool for the comprehensive profiling of protein phosphorylation. Yet the low ionization efficiency and low abundance of phosphopeptides among complex biological samples make its MS analysis challenging; an enrichment strategy with high efficiency and selectivity is always necessary prior to MS analysis. In this study, we developed a phosphorylated cotton-fiber-based Ti(IV)-IMAC material (termed as Cotton Ti-IMAC) that can serve as a novel platform for phosphopeptide enrichment. The cotton fiber can be effectively grafted with phosphate groups covalently in a single step, where the titanium ions can then be immobilized to enable capturing phosphopeptides. The material can be prepared using cost-effective reagents within only 4 h. Benefiting from the flexibility and filterability of cotton fibers, the material can be easily packed as a spin-tip and make the enrichment process convenient. Cotton Ti-IMAC successfully enriched phosphopeptides from protein standard digests and exhibited a high selectivity (BSA/ß-casein = 1000:1) and excellent sensitivity (0.1 fmol/µL). Moreover, 2354 phosphopeptides were profiled in one LC-MS/MS injection after enriching from only 100 µg of HeLa cell digests with an enrichment specificity of up to 97.51%. Taken together, we believe that Cotton Ti-IMAC can serve as a widely applicable and robust platform for achieving large-scale phosphopeptide enrichment and expanding our knowledge of phosphoproteomics in complex biological systems.

Identification of nonvolatile chemical constituents in Chinese Huangjiu using widely targeted metabolomics.

Huangjiu is a traditional Chinese alcoholic beverage, whose non-volatile chemical profile remains unclarified. Here, the non-volatile compounds of Huangjiu were first identified using a widely targeted metabolomics analysis. In total, 1146 compounds were identified, 997 of them were identified in Huangjiu for the first time. Moreover, 113 compounds were identified as key active ingredients of traditional Chinese medicines and 78 components were found as active pharmaceutical ingredients against 389 diseases. In addition, the comparative analysis and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis revealed that Huangjiu from different regions differ in metabolite composition. Cofactor and amino acid biosynthesis and ABC transport were the dominant metabolic pathways. Furthermore, 7 metabolic pathways and 77 metabolic pathway regulatory markers were further found to be related with the different characteristics of different Huangjius. This study provides a theoretical and material basis for the quality control, health efficacy, and industrial development of Huangjiu.

The Different Mechanisms of Lipid Accumulation in Hepatocytes Induced by Oleic Acid/Palmitic Acid and High-Fat Diet.

Non-alcoholic fatty liver disease (NAFLD) is the primary chronic liver disease worldwide, mainly manifested by hepatic steatosis. Hepatic lipids may be derived from dietary intake, plasma free fatty acid (FFA) uptake, or hepatic de novo lipogenesis (DNL). Currently, cellular and animal models of hepatocellular steatosis are widely used to study the pathogenesis of NAFLD and to investigate therapeutic agents. However, whether there are differences between the in vivo and in vitro models of the mechanisms that cause lipid accumulation has not been reported. We used OA/PA-induced NCTC 1469 cells and high-fat-diet-fed C57BL/6J mice to simulate a hepatocyte steatosis model of NAFLD and to detect indicators related to FFA uptake and DNL. In addition, when serological indicators were analysed in the mouse model, it was found that serum FASN levels decreased. The results revealed that, in the cellular model, indicators related to DNL were decreased, FASN enzyme activity was unchanged, and indicators related to FFA uptake were increased, including the high expression of CD36; while, in the animal model, indicators related to both FFA uptake and de novo synthesis were increased, including the high expression of CD36 and the increased protein levels of FASN with enhanced enzyme activity. In addition, after an analysis of the serological indicators in the mouse model, it was found that the serum levels of FASN were reduced. In conclusion, the OA/PA-induced cellular model can be used to study the mechanism of FFA uptake, whereas the high-fat-diet-induced mouse model can be used to study the mechanism of FFA uptake and DNL. Combined treatment with CD36 and FASN may be more effective against NAFLD. FASN in the serum can be used as one of the indicators for the clinical diagnosis of NAFLD.

Superlattice Surface Lattice Resonances in Plasmonic Nanoparticle Arrays with Patterned Dielectrics.

This paper describes how two-dimensional plasmonic nanoparticle lattices covered with microscale arrays of dielectric patches can show superlattice surface lattice resonances (SLRs). These optical resonances originate from multiscale diffractive coupling that can be controlled by the periodicity and size of the patterned dielectrics. The features in the optical dispersion diagram are similar to those of index-matched microscale arrays of metal nanoparticle lattices, having the same lateral dimensions as the dielectric patches. With an increase in nanoparticle size, superlattice SLRs can also support quadrupole excitations with distinct dispersion diagrams. The tunable optical band structure enabled by patterned dielectrics on plasmonic nanoparticle arrays offers prospects for enhanced nonlinear optics, nanoscale lasing, and engineered parity-time symmetries.

Comparison of bacterial and fungal communities structure and dynamics during chicken manure and pig manure composting.

Composting is a sustainable and eco-friendly technology that turns animal waste into organic fertilizers. It remains unclear whether differences exist in the structure of microbial communities during different livestock manure composting. This study analyzed the dynamic change of bacterial and fungal communities, metabolic function, and trophic mode during chicken manure (CM) and pig manure (PM) composting based on 16S rRNA and ITS sequencing. Environmental factors were investigated for their impact on microbial communities. During composting, bacterial diversity decreased and then increased, while fungal diversity slightly increased and then decreased. Saccharomonospora and Aspergillus were the dominant genera and key microorganisms in CM and PM, respectively, which played crucial roles in sustaining the stability of the ecological network structure in the microbial ecology and participating in metabolism. Saccharomonospora gradually increased, while Aspergillus increased at first and then decreased. PM had better microbial community stability and more keystone taxa than CM. In CM and PM, the primary function of bacterial communities was metabolism, while saprotroph was the primary trophic mode of fungal communities. Dissolved organic carbon (DOC) was the primary factor influencing the structure and function of microbial communities in CM and PM. In addition to DOC, pH and moisture were important factors affecting the fungal communities in CM and PM, respectively. These results show that the succession of bacteria and fungi in CM and PM proceeded in a similar pattern, but there are still some differences in the dominant genus and their responses to environmental factors.

Chemotherapy effect on myocardial fibrosis markers in patients with gynecologic cancer and low cardiovascular risk.

Background: Patients with gynecologic cancers experience side effects of chemotherapy cardiotoxicity. We aimed to quantify cardiac magnetic resonance (CMR) markers of myocardial fibrosis in patients with gynecologic cancer and low cardiovascular risk who undergo chemotherapy. Methods: This study is part of a registered clinical research. CMR T1 mapping was performed in patients with gynecologic cancer and low cardiovascular risk undergoing chemotherapy. The results were compared with those of age-matched healthy control subjects. Results: 68 patients (median age = 50 years) and 30 control subjects were included. The median number of chemotherapy cycles of patients was 9.0 (interquartile range [IQR] 3.3-17.0). Extracellular volume fraction (ECV) (27.2% ± 2.7% vs. 24.5% ± 1.7%, P < 0.001) and global longitudinal strain (-16.2% ± 2.8% vs. -17.4% ± 2.0%, P = 0.040) were higher in patients compared with controls. Patients with higher chemotherapy cycles (>6 cycles) (n=41) had significantly lower intracellular mass indexed (ICMi) compared with both patients with lower chemotherapy cycles (≤6 cycles) (n=27) (median 27.44 g/m2 [IQR 24.03-31.15 g/m2] vs. median 34.30 g/m2 [IQR 29.93-39.79 g/m2]; P = 0.002) and the control group (median 27.44 g/m2 [IQR 24.03-31.15 g/m2] vs. median 32.79 g/m2 [IQR 27.74-35.76 g/m2]; P = 0.002). Patients with two or more chemotherapy regimens had significantly lower ICMi compared with both patients with one chemotherapy regimen (27.45 ± 5.16 g/m2 vs. 33.32 ± 6.42 g/m2; P < 0.001) and the control group (27.45 ± 5.16 g/m2 vs. 33.02 ± 5.52 g/m2; P < 0.001). The number of chemotherapy cycles was associated with an increase in the ECV (Standard regression coefficient [ß] = 0.383, P = 0.014) and a decrease in the ICMi (ß = -0.349, P = 0.009). Conclusion: Patients with gynecologic cancer and low cardiovascular risk who undergo chemotherapy have diffuse extracellular volume expansion, which is obvious with the increase of chemotherapy cycles. Myocyte loss may be part of the mechanism in patients with a higher chemotherapy load. Clinical trial registration: http://www.chictr.org.cn, identifier ChiCTR-DDD-17013450.

Correlation between connexin 43 expression in circulating tumor cells and biological characteristics of breast cancer.

Background: Connexin 43 (Cx43) has been closely linked to the occurrence and progression of breast cancer. Distant metastasis of breast cancer is aided by the epithelial-mesenchymal transition of circulating tumor cells (CTCs). However, the impact of Cx43 expression on CTCs and the extent of its role in the disease remain unclear. Methods: We determined CTCs in 156 patients, who had breast cancer with a disease course of two or more years. We also measured the expression of Cx43 in the CTCs. The CTCs were detected in the blood of 139 of these patients. These 139 patients were divided into two groups: the Cx43 group and the non-Cx43 group based on their Cx43 expression. Results: Overall, Cx43 expression was found in 83 of the 139 patients (59.7%, 83/139 cases). The two groups significantly differed in terms of the number of mixed biphenotypic type CTCs and the total number of CTCs (P < 0.05). There were significant correlations between Cx43 expression and Ki67 expression, tumor size, lymph node metastasis, and TNM stage (P < 0.05 for all). The data suggested that patients with Cx43 expression had a higher risk of distant metastasis and had later-stage disease. The difference in Cx43 expression between patients with and without epidermal growth factor receptor 2 (Her2) overexpression was statistically significant (P < 0.05). The difference in disease-free survival (DFS) between the two groups was statistically significant (P = 0.03), and the Cx43 group had a shorter duration of DFS. Univariate Cox regression analysis revealed that Cx43 expression, Her2 expression, and tumor size were significantly correlated with DFS (P = 0.03, 0.0023, and 0.01, respectively). Conclusion: Cx43 expression in the CTCs of patients with breast cancer is a cancer-promoting factor.

Primary ovarian choriocarcinoma occurring in a postmenopausal woman: A case report.

BACKGROUND: Nongestational ovarian choriocarcinoma (NGOC) is a rare but aggressive neoplasm with limited sensitivity to chemotherapy and a very poor prognosis. Few cases of NGOC have been reported, and there is limited information regarding its clinical features, treatment protocols, or prognosis. CASE SUMMARY: A postmenopausal woman in her 5th decade of life visited our clinic because of abnormal vaginal bleeding and an abdominal mass. Although she had been menopausal for more than eight years and her last abortion occurred nine years ago, she had an increased level of serum ß-human chorionic gonadotropin (ß-hCG). Thus, an ovarian neoplasm of trophoblastic origin was suspected, and exploratory laparotomy was performed. Based on the patient's clinical history and the histopathological examination and immunohistochemistry results obtained postoperatively, we concluded that she most likely had primary NGOC. Cytoreductive surgery was performed in combination with adjuvant chemotherapy comprising bleomycin, etoposide, and cisplatin. Serum ß-hCG levels decreased to normal after two cycles, and there was no evidence of recurrence after four cycles of chemotherapy. CONCLUSION: Even in postmenopausal women, ovarian choriocarcinoma should be considered in the initial differential diagnosis for an adnexal mass.

DiLeu Isobaric Labeling Coupled with Limited Proteolysis Mass Spectrometry for High-Throughput Profiling of Protein Structural Changes in Alzheimer's Disease.

High-throughput quantitative analysis of protein conformational changes has a profound impact on our understanding of the pathological mechanisms of Alzheimer's disease (AD). To establish an effective workflow enabling quantitative analysis of changes in protein conformation within multiple samples simultaneously, here we report the combination of N,N-dimethyl leucine (DiLeu) isobaric tag labeling with limited proteolysis mass spectrometry (DiLeu-LiP-MS) for high-throughput structural protein quantitation in serum samples collected from AD patients and control donors. Twenty-three proteins were discovered to undergo structural changes, mapping to 35 unique conformotypic peptides with significant changes between the AD group and the control group. Seven out of 23 proteins, including CO3, CO9, C4BPA, APOA1, APOA4, C1R, and APOA, exhibited a potential correlation with AD. Moreover, we found that complement proteins (e.g., CO3, CO9, and C4BPA) related to AD exhibited elevated levels in the AD group compared to those in the control group. These results provide evidence that the established DiLeu-LiP-MS method can be used for high-throughput structural protein quantitation, which also showed great potential in achieving large-scale and in-depth quantitative analysis of protein conformational changes in other biological systems.

ATP-Coated Dual-Functionalized Titanium(IV) IMAC Material for Simultaneous Enrichment and Separation of Glycopeptides and Phosphopeptides.

Protein glycosylation and phosphorylation are two of the most common post-translational modifications (PTMs), which play an important role in many biological processes. However, low abundance and poor ionization efficiency of phosphopeptides and glycopeptides make direct MS analysis challenging. In this study, we developed a hydrophilicity-enhanced bifunctional Ti-IMAC (IMAC: immobilized metal affinity chromatography) material with grafted adenosine triphosphate (denoted as epoxy-ATP-Ti4+) to enable simultaneous enrichment and separation of common N-glycopeptides, phosphopeptides, and M6P glycopeptides from tissue/cells. The enrichment was achieved through a dual-mode mechanism based on the electrostatic and hydrophilic properties of the material. The epoxy-ATP-Ti4+ IMAC material was prepared from epoxy-functionalized silica particles via a convenient two-step process. The ATP molecule provided strong and active phosphate sites for binding phosphopeptides in the conventional IMAC mode and also contributed significantly to the hydrophilicity, which permitted the enrichment of glycopeptides via hydrophilic interaction chromatography. The two modes could be implemented simultaneously, allowing glycopeptides and phosphopeptides to be collected sequentially in a single experiment from the same sample. In addition to standard protein samples, the material was further applied to glycopeptide and phosphopeptide enrichment and characterization from HeLa cell digests and mouse lung tissue samples. In total, 2928 glycopeptides and 3051 phosphopeptides were identified from the mouse lung tissue sample, supporting the utility of this material for large-scale PTM analysis of complex biological samples. Overall, the newly developed epoxy-ATP-Ti4+ IMAC material and associated fractionation method enable simple and effective enrichment and separation of glycopeptides and phosphopeptides, offering a useful tool to study potential crosstalk between these two important PTMs in biological systems. The MS data have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the data set identifier PXD029775.

Uncarboxylated Osteocalcin Decreases SCD1 by Activating AMPK to Alleviate Hepatocyte Lipid Accumulation.

Uncarboxylated osteocalcin (GluOC), a small-molecule protein specifically synthesized and secreted by osteoblasts, is important in the regulation of energy metabolism. In our previous study, GluOC was shown to be effective in ameliorating dyslipidemia and hepatic steatosis in KKAy mice. However, the underlying mechanism of GluOC action on hepatocytes has not been well validated. In this study, oleic acid/palmitic acid (OA/PA)-induced HepG2 and NCTC 1469 cells were used as non-alcoholic fatty liver disease (NAFLD) cell models, and triacylglycerol (TG) levels were measured by oil red O staining, Nile Red staining, and ELISA. The fatty acid synthesis-related protein expression was detected by real-time quantitative polymerase chain reaction, Western blotting, and immunofluorescence. The results show that GluOC reduced triglyceride levels, and decreased the expression of sterol regulatory element-binding protein-1c (SREBP-1c) and stearyl-coenzyme A desaturase 1 (SCD1). si-SCD1 mimicked the lipid accumulation-reducing effect of GluOC, while overexpression of SCD1 attenuated the effect of GluOC. In addition, GluOC activated AMP-activated protein kinase (AMPK) phosphorylation to affect lipid metabolism in hepatocytes. Overall, the results of this study suggest that GluOC decreases SCD1 by activating AMPK to alleviate hepatocyte lipid accumulation, which provides a new target for improving NAFLD in further research.