Clinicopathologic characteristics of HPV-associated head and neck squamous cell carcinoma in Southern China: long-term retrospective study of 400 cases.

Background: Human papillomavirus (HPV)-associated head and neck squamous cell carcinoma (HNSCC) is an evolving and growing disease, especially in developing countries. However, the clinical characteristics of HPV-associated HNSCC in regard to HPV infection rates, patient features, and prognosis are under-reported in the Asian population. Methods: In this study, we retrospectively enrolled a 400-case cohort of HNSCC with p16 immunochemistry and analyzed with long-term follow-up. We investigate the current HPV prevalence of HNSCC, unique HPV-associated patient clinical characteristics, and patient prognosis in the southern China population. Results: HPV infection exhibited a 15% prevalence in all HNSCC cases, notably higher in oropharyngeal cases (30.7%), followed by oral cavity (11.8%), laryngeal (10.1%), and hypopharyngeal (2.5%). HPV status, gender, old age, and location of tumor were significantly associated with the patient's survival. Tonsil invasion was found more frequent in HPV-positive oropharyngeal HNSCC than in HPV-negative cases. HPV-associated HNSCC patients tend to possess stronger tobacco and alcohol habits, which were correlated to poor survival. HPV status's correlation with gender, age, and anatomical location is associated intricately with patient survival. The secondary primary tumor rate was found higher within the HPV-negative group, compared to the HPV-positive group (9.12% versus 1.67%). Conclusion: Our study provided a current picture of HPV-associated HNSCC in the southern China population and elaborated the understanding of key factors that correlate to HNSCC prognosis. Our findings indicated a strong susceptibility of HPV-associated oropharyngeal HNSCC in the tonsil and the difference in secondary primary tumor rates associated with HPV status.

HPV in head and neck cancer In this study, we retrospectively enrolled a 400-case cohort of HNSCC with p16 immunochemistry and analyzed with long-term follow-up. We investigate the current HPV prevalence of HNSCC, unique HPV-associated patient characteristics, along with patient prognosis in southern China population. Our findings indicated a strong susceptibility of HPV-associated oropharyngeal HNSCC in tonsil and difference of secondary primary tumor associated with HPV status. Our study provided a current picture of HPV-associated HNSCC in southern China population and elaborated the understanding of key factors that correlate to HNSCC prognosis.

Progress of nanopreparation technology applied to volatile oil drug delivery systems.

Traditional Chinese medicine volatile oil has a long history and possesses extensive pharmacological activity. However, volatile oils have characteristics such as strong volatility, poor water solubility, low bioavailability, and poor targeting, which limit their application. The use of volatile oil nano drug delivery systems can effectively improve the drawbacks of volatile oils, enhance their bioavailability and chemical stability, and reduce their volatility and toxicity. This article first introduces the limitations of the components of traditional Chinese medicine volatile oils, discusses the main classifications and latest developments of volatile oil nano formulations, and briefly describes the preparation methods of traditional Chinese medicine volatile oil nano formulations. Secondly, the limitations of nano formulation technology are discussed, along with future challenges and prospects. A deeper understanding of the role of nanotechnology in traditional Chinese medicine volatile oils will contribute to the modernization of volatile oils and broaden their application value.

Neoadjuvant chemoimmunotherapy shows major pathological response and low recurrence in head and neck squamous cell carcinoma.

BACKGROUND: The study aimed to investigate the efficacy and survival outcomes of neoadjuvant chemotherapy combined with programmed cell death protein 1 (PD-1) blockade (neoadjuvant chemoimmunotherapy) for patients with resectable head and neck squamous cell carcinoma (HNSCC). METHODS: A retrospective analysis was conducted. Patients with initially diagnosed, resectable HNSCCs who received the neoadjuvant chemoimmunotherapy and radical surgery were included. Correlation analysis between patients' clinical characteristics and pathological responses, and survival analysis were performed. RESULTS: A total of 79 patients were included. The majority of patients (55, 69.6%) were diagnosed at locally advanced stages and most of them (58, 73.4%) had tumor located at the oral cavity. Nearly half of patients (35, 44.3%) received two cycles of neoadjuvant chemoimmunotherapy and the rest had three or more cycles. The R0 resection rate was 98.7%. In the pathological evaluation, 53.1% of patients reached pathological complete responses or major pathological responses. After a median follow-up of 17.0 months, the 1-year disease-free survival (DFS) and overall survival (OS) rates were 87.2% and 97.4%, respectively. The pathological response showed a significantly positive association with survival benefits (p < 0.001). Patients with human papillomavirus (HPV)-positive oropharyngeal cancer had the best pathological response and survival outcomes. Besides, history of radiation at head and neck region and poor pathological response were found to be independent risk factors of DFS for patients receiving such treatments. CONCLUSION: Neoadjuvant chemoimmunotherapy of HNSCC showed high rate of pathological response and low recurrence rate, holding promise for becoming the new standard of care for resectable HNSCC.

Characterization of Oxidized Glycerophosphoethanolamines via Radical-Directed Dissociation Tandem Mass Spectrometry and the Paternò-Büchi Derivatization.

Oxidized glycerophosphoethanolamines (oxPEs) represent a subclass of bioactive lipids that have intricate roles in various physiological and pathological events. Conventional mass spectrometric methods cannot provide unambiguous information to locate the OH group and the sites of unsaturation. Herein, we report a combined strategy for in-depth structural characterization of oxPEs, including radical-directed dissociation tandem mass spectrometry (RDD-MS/MS) for localizing the OH group and the Paternò-Büchi derivatization coupled with tandem mass spectrometry for pinpointing carbon-carbon double-bond locations. The RDD-MS/MS method has been integrated on a reversed-phase liquid chromatography-mass spectrometry workflow. It enables the profiling of 24 distinct oxPE molecules with unequivocal assignment of the OH sites at nM sensitivity in bovine liver lipid extract treated by soybean 15-lipoxygenase. These findings showcase that the developed method has a good potential in analyzing biological systems where oxPEs may play important roles.

Development and validation of web-based prognostic nomograms for massive hepatocellular carcinoma (≥10 cm): A retrospective study based on the SEER database.

BACKGROUND AND AIMS: Massive hepatocellular carcinoma (MHCC, a maximum tumor size of at least 10 cm) tends to have a poor prognosis. Therefore, this study aims to construct and validate prognostic nomograms for MHCC. METHODS: Clinic data of 1292 MHCC patients between 2010 and 2015 were got from the surveillance, epidemiology, and end results (SEER) cancer registration database. The whole set was separated into the training and validation sets at a ratio of 2:1 randomly. Variables, significantly associated with cancer-specific (CSS) and overall survival (OS) of MHCC were figured out by multivariate Cox regression analysis and were taken to develop nomograms. The concordance index (C-index), calibration curve, and decision curve analysis (DCA) were taken to validate the predictive abilities and accuracy of the nomograms. RESULTS: Race, alpha-fetoprotein (AFP), grade, combined summary stage, and surgery were identified as independent factors of CSS, and fibrosis score, AFP, grade, combined summary stage, and surgery significantly correlated with OS in the training cohort. They then were taken to construct prognostic nomograms. The constructed model for predicting CSS exhibited satisfactory performance with a C-index of 0.727 (95% CI: 0.746-0.708) in the training group and 0. 672 (95% CI: 0.703-0.641) in the validation group. Besides, the model for predicting OS of MHCC also showed strong performance both in the training group (C-index: 0.722, 95% CI: 0.741-0.704) and the validation (C-index: 0.667, 95% CI: 0.696-0.638) group. All calibration curves and decision curves performed satisfactory predictive accuracy and clinic application values of the nomograms. CONCLUSION: The web-based nomograms for CSS and OS of MHCC were developed and validated in this study, which prospectively could be tested and may serve as additional tools to assess patient's individualized prognosis and make precise therapeutic selection to improve the poor outcome of MHCC.

Origin and chromatin remodeling of young X/Y sex chromosomes in catfish with sexual plasticity.

Assembly of a complete Y chromosome is a significant challenge in animals with an XX/XY sex-determination system. Recently, we created YY-supermale yellow catfish by crossing XY males with sex-reversed XY females, providing a valuable model for Y-chromosome assembly and evolution. Here, we assembled highly homomorphic Y and X chromosomes by sequencing genomes of the YY supermale and XX female in yellow catfish, revealing their nucleotide divergences with only less than 1% and with the same gene compositions. The sex-determining region (SDR) was identified to locate within a physical distance of 0.3 Mb by FST scanning. Strikingly, the incipient sex chromosomes were revealed to originate via autosome-autosome fusion and were characterized by a highly rearranged region with an SDR downstream of the fusion site. We found that the Y chromosome was at a very early stage of differentiation, as no clear evidence of evolutionary strata and classical structure features of recombination suppression for a rather late stage of Y-chromosome evolution were observed. Significantly, a number of sex-antagonistic mutations and the accumulation of repetitive elements were discovered in the SDR, which might be the main driver of the initial establishment of recombination suppression between young X and Y chromosomes. Moreover, distinct three-dimensional chromatin organizations of the Y and X chromosomes were identified in the YY supermales and XX females, as the X chromosome exhibited denser chromatin structure than the Y chromosome, while they respectively have significantly spatial interactions with female- and male-related genes compared with other autosomes. The chromatin configuration of the sex chromosomes as well as the nucleus spatial organization of the XX neomale were remodeled after sex reversal and similar to those in YY supermales, and a male-specific loop containing the SDR was found in the open chromatin region. Our results elucidate the origin of young sex chromosomes and the chromatin remodeling configuration in the catfish sexual plasticity.

LipidOA: A Machine-Learning and Prior-Knowledge-Based Tool for Structural Annotation of Glycerophospholipids.

The Paternò-Büchi (PB) reaction is a carbon-carbon double bond (C═C)-specific derivatization reaction that can be used to pinpoint the location(s) of C═C(s) in unsaturated lipids and quantitate the location of isomers when coupled with tandem mass spectrometry (MS/MS). As the data of PB-MS/MS are increasingly generated, the establishment of a corresponding data analysis tool is highly needed. Herein, LipidOA, a machine-learning and prior-knowledge-based data analysis tool, is developed to analyze PB-MS/MS data generated by liquid chromatography-mass spectrometry workflows. LipidOA consists of four key functional modules to realize an annotation of glycerophospholipid (GPL) structures at the fatty acyl-specific C═C location level. These include (1) data preprocessing, (2) picking C═C diagnostic ions, (3) de novo annotation, and (4) result ranking. Importantly, in the result-ranking module, the reliability of structural annotation is sorted via the use of a machine learning classifier and comparison to the total fatty acid database generated from the same sample. LipidOA is trained and validated by four PB-MS/MS data sets acquired using different PB reagents on mass spectrometers of different resolutions and of different biological samples. Overall, LipidOA provides high precision (higher than 0.9) and a wide coverage for structural annotations of GPLs. These results demonstrate that LipidOA can be used as a robust and flexible tool for annotating PB-MS/MS data collected under different experimental conditions using different lipidomic workflows.

Inhibition of cannabinoid receptor type 1 sensitizes triple-negative breast cancer cells to ferroptosis via regulating fatty acid metabolism.

Triple-negative breast cancer (TNBC) is a heterogeneous subtype of breast cancer that displays highly aggressive with poor prognosis. Owing to the limited targets and drugs for TNBC clinical therapy, it is necessary to investigate the factors regulating cancer progression and develop novel therapies for cancer treatment. Ferroptosis, a nonapoptotic form of programmed cell death characterized by accumulation of iron-dependent peroxidation of phospholipids, is regulated by cellular metabolism, redox homeostasis, and various cancer-related signaling pathways. Recently, considerable progress has been made in demonstrating the critical role of lipid metabolism in regulating ferroptosis, indicating potential combinational therapeutic strategies for cancer treatment. In this study, by drug combination screen of lipid metabolism compounds with ferroptosis inducers in decreasing TNBC cell viability, we found potent synergy of the CB1 antagonist rimonabant with erastin/(1 S, 3 R)-RSL3 (RSL3) in inhibiting TNBC cell growth both in vitro and in vivo via promoting the levels of lipid peroxides, malondialdehyde (MDA), 4-hydroxynonenal (4-HNE) and cytosolic reactive oxygen species (ROS) production, enhancing intracellular glutathione (GSH) depletion and inducing G1 cell cycle arrest. We identified that inhibition of CB1 promoted the effect of erastin/RSL3 on inducing ferroptosis and enhanced their inhibitory effect on tumor growth. Using RNA-Seq, fatty acid analyses and functional assays, we found that CB1 regulated stearoyl-CoA desaturase 1 (SCD1)- and fatty acyl desaturase 2 (FADS2)-dependent fatty acid metabolism via phosphatidylinositol 3 kinase (PI3K)-AKT and mitogen-activated protein kinase (MAPK) signaling pathways to modulate ferroptosis sensitivity in TNBC cells. These data demonstrate that dual targeting of CB1 and ferroptosis could be a promising therapeutic strategy for TNBC.

Genome-wide association study reveals the genetic basis of growth trait in yellow catfish with sexual size dimorphism.

Sexual size dimorphism has been widely observed in a large number of animals including fish species. Genome-wide association study (GWAS) is a powerful tool to dissect the genetic basis of complex traits, whereas the sex-differences in the genomics of animal complex traits have been ignored in the GWAS analysis. Yellow catfish (Pelteobagrus fulvidraco) is an important aquaculture fish in China with significant sexual size dimorphism. In this study, GWAS was conducted to identify candidate SNPs and genes related to body length (BL) and body weight (BW) in 125 female yellow catfish from a breeding population. In total, one BL-related SNP and three BW-related SNPs were identified to be significantly associated with the traits. Besides, one of these SNPs (Chr15:19195072) was shared in both the BW and BL traits in female yellow catfish, which was further validated in 185 male individuals and located on the exon of stat5b gene. Transgenic yellow catfish and zebrafish that expressed yellow catfish stat5b showed increased growth rate and reduction of sexual size dimorphism. These results not only reveal the genetic basis of growth trait and sexual size dimorphism in fish species, but also provide useful information for the marker-assisted breeding in yellow catfish.

Profiling of branched-chain fatty acids via nitroxide radical-directed dissociation integrated on an LC-MS/MS workflow.

Chain modifications on fatty acyls, such as methyl branching, are important to modulate the biochemical and biophysical properties of lipids. The current lipid analysis workflows which mainly rely on collisional-induced dissociation (CID) to obtain the structural information of lipids often fail in locating the chain modifications. Radical-directed dissociation (RDD) is a new type of tandem mass spectrometry (MS/MS) method capable of producing intrachain cleavages, thus allowing the detailed characterization of lipid structures. In this study, we have developed an RDD method induced by nitroxide radicals (NO˙) for the analysis of branched-chain fatty acids (BCFAs). Fatty acids (FAs) are first amidated by O-benzylhydroxylamine; MS2 CID of the lithium adduct ion of the derivatized FAs uncages the nitroxide radical, which subsequently initiates RDD along the chain. The location of methyl branching can be determined via characteristic 28 Da spacing due to cleavages on either side of the branching point, with enhanced fragmentation observed toward the carbonyl end. This nitroxide-RDD method has been integrated onto reversed-phase liquid chromatography and applied for the profiling of BCFAs from yak milk powder and pooled human plasma samples. Other than the more often encountered iso- and anteiso-BCFAs, we have identified FA n-5 17 : 0 as a minor component from human plasma, which has been rarely reported before.

Localization of Intrachain Modifications in Bacterial Lipids Via Radical-Directed Dissociation.

Intrachain modifications of membrane glycerophospholipids (GPLs) due to formation of the carbon-carbon double bond (C═C), cyclopropane ring, and methyl branching are crucial for bacterial membrane homeostasis. Conventional collision-induced dissociation (CID) of even-electron ions of GPL favors charge-directed fragmentation channels, and thus little structurally informative fragments can be detected for locating intrachain modifications. In this study, we report a radical-directed dissociation (RDD) approach for characterization of the intrachain modifications within phosphoethanolamines (PEs), a major lipid component in bacterial membrane. In this method, a radical precursor that can produce benzyl or pyridine methyl radical upon low-energy CID at high efficiency is conjugated onto the amine group of PEs. The carbon-centered radical ions subsequently initiate RDD along the fatty acyl chain, producing fragment patterns key to the assignment and localization of intrachain modifications including C═C, cyclopropane rings, and methyl branching. Besides intrachain fragmentation, RDD on the glycerol backbone produces fatty acyl loss as radicals, allowing one to identify the fatty acyl chain composition of PE. Moreover, RDD of lyso-PEs produces radical losses for distinguishing the sn-isomers. The above RDD approach has been incorporated onto a liquid chromatography-mass spectrometry workflow and applied for the analysis of lipid extracts from Escherichia coli and Bacillus subtilis.

Deep Profiling of Aminophospholipids Reveals a Dysregulated Desaturation Pattern in Breast Cancer Cell Lines.

Phosphatidylethanolamines (PEs), ether-PEs, and phosphatidylserines (PSs) are glycerophospholipids harboring a primary amino group in their headgroups. They are key components of mammalian cell membranes and play pivotal roles in cell signaling and apoptosis. In this study, a liquid chromatography-mass spectrometry (LC-MS) workflow for deep profiling of PEs, ether-PEs, and PSs has been developed by integrating two orthogonal derivatizations: (1) derivatization of the primary amino group by 4-trimethylammoniumbutyryl-N-hydroxysuccinimide (TMAB-NHS) for enhanced LC separation and MS detection and (2) the Paternò-Büchi (PB) reaction for carbon-carbon double bond (C═C) derivatization and localization. Significant improvement of the limit of identification down to the C═C location has been achieved for the standards of PSs (3 nM) and ether-PEs (20 nM). This workflow facilitates an identification of more than 200 molecular species of aminophospholipids in the porcine brain, two times more than those identified without TMAB-NHS derivatization. Importantly, we discovered that the n-10 isomers in C16:1 and C18:1 of aminophospholipids showed elevated contribution among other isomers, which correlated well with an increased transcription of the corresponding desaturase (FADS2) in the human breast cancer cell line (MDA-MB-231) relative to that in the normal cell line (HMEC). The abovementioned data suggest that lipid reprograming via forming different C═C location isomers might be an alternative mechanism in cancer cells.

Mechanisms of Dihuang (Rehmanniae Radix) in treating diabetic nephropathy complicated with depression based on network pharmacology / 数字中医药（英文）

@#Objective To predict the molecular mechanism of Dihuang (Rehmanniae Radix) in the treatment of diabetic nephropathy (DN) complicated with depression based on network pharmacology. Methods The components of Dihuang (Rehmanniae Radix) were identified from the Integrated Pharmacology-based Research Platform of Traditional Chinese Medicine (TCMIP), Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP), and relevant literature. The component targets were detected by combining the SwissTargetPrediction and PubChem databases. Disease targets were collected from the Therapeutic Target Database (TTD), DisGeNET, and Ensembl databases with “diabetic nephropathy” and “depression” as keywords. The disease-component targets were mapped using Venny 2.1.0 to obtain potential targets. A protein-protein interaction (PPI) network was constructed using the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database and Cytoscape 3.7.2. The co-expression genes of the key targets were collected based on the COXPRESdb 7.3. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis were performed for potential targets using R language. Target-component docking was verified and evaluated using Discovery Studio 4.5. Results According to the databases and literature reports, Dihuang (Rehmanniae Radix) contained 65 active components, and had 155 related targets for the treatment of DN complicated with depression. PPI screening showed that the key targets included serine/threonine protein kinase 1 (AKT1), signal transducer and activator transcription 3 (STAT3), interleukin 6 (IL-6), mitogen-activated protein kinase 1 (MAPK1), and vascular endothelial growth factor A (VEGFA), etc. GO enrichment analysis mainly involved biological processes, such as lipid metabolism, protein secretion regulation, cell homeostasis, and phosphatidylinositol 3 kinase activity. KEGG pathway enrichment analysis included the role of the AGE-RAGE signaling pathway in diabetic complements, insulin resistance (IR), neurotrophin signal path, Toll-like receptor signaling pathway, relaxin signaling pathway, epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), etc. Molecular docking showed that the target had high affinity for stachyose, manninotriose, verbascose, nigerose, etc. Conclusion Based on network parmacology, this study preliminarily predict the effects of Dihuang (Rehmanniae Radix) in treating DN complicated with depression by regulating inflammation, glucose metabolism, nution nerve, etc.

Single-cell lipidomics with high structural specificity by mass spectrometry.

Single-cell analysis is critical to revealing cell-to-cell heterogeneity that would otherwise be lost in ensemble analysis. Detailed lipidome characterization for single cells is still far from mature, especially when considering the highly complex structural diversity of lipids and the limited sample amounts available from a single cell. We report the development of a general strategy enabling single-cell lipidomic analysis with high structural specificity. Cell fixation is applied to retain lipids in the cell during batch treatments prior to single-cell analysis. In addition to tandem mass spectrometry analysis revealing the class and fatty acyl-chain for lipids, batch photochemical derivatization and single-cell droplet treatment are performed to identify the C=C locations and sn-positions of lipids, respectively. Electro-migration combined with droplet-assisted electrospray ionization enables single-cell mass spectrometry analysis with easy operation but high efficiency in sample usage. Four subtypes of human breast cancer cells are correctly classified through quantitative analysis of lipid C=C location or sn-position isomers in ~160 cells. Most importantly, the single-cell deep lipidomics strategy successfully discriminates gefitinib-resistant cells from a population of wild-type human lung cancer cells (HCC827), highlighting its unique capability to promote precision medicine.

Next-Generation Paternò-Büchi Reagents for Lipid Analysis by Mass Spectrometry.

The Paternò-Büchi (PB) reaction is a photochemical reaction involving [2 + 2] cycloaddition between electronically excited carbonyl and carbon-carbon double bond (C═C). It has been established as a lipid derivatization strategy, leading to confident assignment of C═C locations in lipids when coupled with tandem mass spectrometry (MS/MS). Although acetone and several aryl-containing ketones or aldehydes have been explored as PB reagents, the chemical properties critical to achieving efficient conversion and minimum side reactions remain unclear. Herein, we investigated a set of acetophenone (AP) derivatives, aiming to provide insights into the development of new PB reagents with enhanced performance for lipid analysis. For AP derivatives, we found that electron-withdrawing groups (e.g., -F and -CF3) on the benzene ring improved the overall conversion, while a bulky group at the ortho-position decreased the conversion. Norrish Type I cleavage was largely diminished; however, the Norrish Type II side reaction was more competitive, producing products isomeric to the PB reaction products. Among all AP derivatives tested, 2',4',6'-trifluoroacetophenone (triFAP) showed the best performance. It offered a relatively high PB yield (20-30%) for different types of C═C, high sensitivity (sub-nM) for C═C identification, and accurate isomer quantitation. Due to the significantly reduced chemical interferences in shotgun analysis, triFAP provided better performance than that from acetone PB-MS/MS. An offline triFAP PB reaction was implemented in a liquid chromatography analysis workflow, which enabled the large-scale identification of phospholipids including C═C location isomers from a complex lipid extract.

Igf2bp3 maintains maternal RNA stability and ensures early embryo development in zebrafish.

Early embryogenesis relies on maternally inherited mRNAs. Although the mechanism of maternal mRNA degradation during maternal-to-zygotic transition (MZT) has been extensively studied in vertebrates, how the embryos maintain maternal mRNA stability remains unclear. Here, we identify Igf2bp3 as an important regulator of maternal mRNA stability in zebrafish. Depletion of maternal igf2bp3 destabilizes maternal mRNAs prior to MZT and leads to severe developmental defects, including abnormal cytoskeleton organization and cell division. However, the process of oogenesis and the expression levels of maternal mRNAs in unfertilized eggs are normal in maternal igf2bp3 mutants. Gene ontology analysis revealed that these functions are largely mediated by Igf2bp3-bound mRNAs. Indeed, Igf2bp3 depletion destabilizes while its overexpression enhances its targeting maternal mRNAs. Interestingly, igf2bp3 overexpression in wild-type embryos also causes a developmental delay. Altogether, these findings highlight an important function of Igf2bp3 in controlling early zebrafish embryogenesis by binding and regulating the stability of maternal mRNAs.

Analysis of ether glycerophosphocholines at the level of C[double bond, length as m-dash]C locations from human plasma.

Plasmanyl and plasmenyl glycerophosphocholine are ether lipids featuring the 1-O-alkyl or 1-O-alk-1'-enyl ether linkage at the sn-1 position of the glycerol backbone, respectively. Aberrant levels of ether glycerophosphocholines (ether PCs) have been correlated with cellular dysfunctions and various human diseases. Profiling ether PCs with accurate structural information is challenging because of the common presence of isomeric and isobaric species in a lipidome. The Paternò-Büchi (PB) reaction, a double bond (C[double bond, length as m-dash]C) specific derivatization method, is capable of pinpointing C[double bond, length as m-dash]C locations in unsaturated lipids, when coupled with subsequent tandem mass spectrometry (MS/MS). In this study, we have tailored the acetone PB reaction for the analysis of ether PCs. PB-MS/MS via low energy collision-induced dissociation (CID) provides diagnostic ions specific to the alkenyl ether C[double bond, length as m-dash]C bond, which are different from those derived from the isolated C[double bond, length as m-dash]C bond in the alkyl or acyl chain, thereby facilitating the distinction of isomeric plasmenyl from plasmanyl PCs. PB-MS/MS coupled with high resolution MS and multi-stage MS/MS further enable confident identification of isomeric ether PCs and isobaric diacyl PCs from mixtures. A total of 45 ether PCs in human plasma have been identified for ether linkage type and chain composition, while 28 ether PCs have structures being fully characterized down to C[double bond, length as m-dash]C locations.

A novel PDZ domain-containing gene is essential for male sex differentiation and maintenance in yellow catfish (Pelteobagrus fulvidraco).

The sex-determining genes are found to be variable among different fish species. Yellow catfish (Pelteobagrus fulvidraco) is an important aquaculture fish species in China with XX/XY sex-determining type. Recently, YY super-male yellow catfish has been successfully produced by combining hormonal-induced sex reversal method with sex chromosome-linked markers. Here, we identified a novel PDZ domain-containing gene in yellow catfish designated as pfpdz1, in whose intron the sex-linked marker was located. The coding sequence of pfpdz1 in Y chromosome was identical to that in X chromosome except a missense SNP (A/T) that changes an amino acid (E8V) in the N-terminal region. Pfpdz1 displayed male-specific expression during sex differentiation. Overexpression of pfpdz1 using additive transgenesis induces XX ovary to differentiate into testis-like tissue, while the targeted inactivation of pfpdz1 in Y chromosome using CRISPR/Cas9-mediated mutagenesis triggers ovarian differentiation. Furthermore, we demonstrated that pfpdz1 initiates testicular differentiation through upregulating expression of amh, dmrt1 and sox9a1, as well as downregulating expression of cyp19a1, foxl2 and wnt4. Our data provide functional evidence that pfpdz1 is significant for male differentiation and maintenance in yellow catfish.

Distinct and Cooperative Roles of amh and dmrt1 in Self-Renewal and Differentiation of Male Germ Cells in Zebrafish.

Spermatogenesis is a fundamental process in male reproductive biology and depends on precise balance between self-renewal and differentiation of male germ cells. However, the regulative factors for controlling the balance are poorly understood. In this study, we examined the roles of amh and dmrt1 in male germ cell development by generating their mutants with Crispr/Cas9 technology in zebrafish. Amh mutant zebrafish displayed a female-biased sex ratio, and both male and female amh mutants developed hypertrophic gonads due to uncontrolled proliferation and impaired differentiation of germ cells. A large number of proliferating spermatogonium-like cells were observed within testicular lobules of the amh-mutated testes, and they were demonstrated to be both Vasa- and PH3-positive. Moreover, the average number of Sycp3- and Vasa-positive cells in the amh mutants was significantly lower than in wild-type testes, suggesting a severely impaired differentiation of male germ cells. Conversely, all the dmrt1-mutated testes displayed severe testicular developmental defects and gradual loss of all Vasa-positive germ cells by inhibiting their self-renewal and inducing apoptosis. In addition, several germ cell and Sertoli cell marker genes were significantly downregulated, whereas a prominent increase of Insl3-positive Leydig cells was revealed by immunohistochemical analysis in the disorganized dmrt1-mutated testes. Our data suggest that amh might act as a guardian to control the balance between proliferation and differentiation of male germ cells, whereas dmrt1 might be required for the maintenance, self-renewal, and differentiation of male germ cells. Significantly, this study unravels novel functions of amh gene in fish.

Characterization and development of EST-SSR markers derived from transcriptome of yellow catfish.

Yellow catfish (Pelteobagrus fulvidraco) is one of the most important freshwater fish due to its delicious flesh and high nutritional value. However, lack of sufficient simple sequence repeat (SSR) markers has hampered the progress of genetic selection breeding and molecular research for yellow catfish. To this end, we aimed to develop and characterize polymorphic expressed sequence tag (EST)-SSRs from the 454 pyrosequencing transcriptome of yellow catfish. Totally, 82,794 potential EST-SSR markers were identified and distributed in the coding and non-coding regions. Di-nucleotide (53,933) is the most abundant motif type, and AC/GT, AAT/ATT, AAAT/ATTT are respective the most frequent di-, tri-, tetra-nucleotide repeats. We designed primer pairs for all of the identified EST-SSRs and randomly selected 300 of these pairs for further validation. Finally, 263 primer pairs were successfully amplified and 57 primer pairs were found to be consistently polymorphic when four populations of 48 individuals were tested. The number of alleles for the 57 loci ranged from 2 to 17, with an average of 8.23. The observed heterozygosity (HO), expected heterozygosity (HE), polymorphism information content (PIC) and fixation index (fis) values ranged from 0.04 to 1.00, 0.12 to 0.92, 0.12 to 0.91 and -0.83 to 0.93, respectively. These EST-SSR markers generated in this study could greatly facilitate future studies of genetic diversity and molecular breeding in yellow catfish.