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Jiao, L.

Publications and source records attributed to Jiao, L..

13 recordsLinked to original sources

Particle association and monsoon seasonality influence microbial communities in marine coastal waters of Singapore

Marine microbial communities vary seasonally and spatially, shaped by physiochemical gradients and biotic interactions. Spatiotemporal variability of seawater microbiomes in tropical coastal regions is comparatively understudied, especially in Southeast Asia with high pressures from development and anthropogenic activities. Here, we examined the microspatial and temporal variability of bacterioplankton in the Singapore Strait, which is a tropical system in Southeast Asia influenced by monsoons. By applying total community amplicon sequencing to three particle size fractions reflecting microspatial habitats of seawater (0.22-1 {micro}m ''free-living'', 1-10 {micro}m ''large cells and small aggregates'' and 10-150 {micro}m ''particle-associated''), we show that the seawater microbial community was structured by their microspatial habitats, monsoon seasons and physiochemical variables. Monsoon-driven alternation of water masses originating from the South China Sea to the East and from off the Sumatran coast to the West resulted in a distinct community during the Southwest monsoon across all three size fractions. Total DNA (biomass) was lowest in the 10-150 {micro}m fraction, but these particle-associated sequences had the highest diversity and were surprisingly enriched with picocyanobacterial and some pathogenic taxa, potentially reflecting aggregate formation and/or host-derived particle association. This fraction also exhibited greater temporal variability than the two smaller fractions, which could be related to a more heterogenous environment in particle microhabitats. Overall, this study demonstrated compositional variability in the bacterioplankton across space and time in an equatorial region influenced by monsoons.

microbiology↗

Frataxin deficiency drives cardiac dysfunction and transcriptional dysregulation in Friedreich ataxia iPSC model

Friedreich ataxia (FRDA) is a progressive neuromuscular degenerative disorder caused by GAA repeat expansions in the FXN gene, leading to frataxin deficiency and multisystem pathology. Cardiomyopathy is the leading cause of mortality in individuals with FRDA. To investigate the cellular and molecular mechanisms underlying FRDA-associated cardiac dysfunction, we employed induced pluripotent stem cell (iPSC) lines derived from three individuals with FRDA, each paired with an isogenic control line generated through CRISPR/Cas9-mediated excision of the pathogenic GAA repeat expansion. Correction of the mutation restored FXN expression to levels comparable to healthy donor iPSCs, and all lines differentiated efficiently into cardiomyocytes. Functional analysis revealed significant contractile abnormalities in FRDA cardiomyocytes and multicellular cardiac microtissues, including prolonged contraction and relaxation times and faster beating rates, consistent with clinical observations of cardiac contractile dysfunction. FRDA cardiomyocytes also exhibited pathological features such as increased cell size, irregular calcium transients, elevated mitochondrial reactive oxygen species levels, increased mitochondrial fission and increased cell death. These phenotypes were exacerbated by pathological levels of iron supplementation in culture media, highlighting the heightened sensitivity of frataxin-deficient cardiomyocytes to iron-induced metabolic stress. RNA sequencing revealed a distinct transcriptional profile associated with frataxin deficiency. MEG3 and PCDHGA10 were consistently dysregulated across all three FRDA-iPSC lines and may represent early molecular markers of FRDA cardiomyopathy. Together, these findings establish a robust human iPSC model of FRDA cardiomyopathy that captures early disease phenotypes and reveals novel molecular targets. This preclinical human model provides valuable insight into the pathogenesis of FRDA and provides a platform for developing early-stage therapeutic interventions.

pathology↗

Multiomics analysis revealed anti-freezing mechanism of Staphylococcus aureus in its anti-freezing strain

Frozen food is currently a common food type. However, the presence of Staphylococcus aureus contamination caused serious challenge to frozen food safety. In this study, we explored the differences between sensitive strains and anti-freeze strains through multiomics analysis such as proteomics, phosphorylated proteomics, and metabolomics studies to understand the anti-freezing mechanism of S. aureus. This study compared the proteomics, phosphorylated proteomics and metabolomic differences between anti-freeze strains and sensitive strains before and after freezing. pre- and post-freezing, antifreeze strains mainly responded to low temperatures by enhancing antioxidant capacity, energy metabolism and antibiotic synthesis before freezing, while after freezing, bacteria depended more on biofilm formation, nitrogen metabolism and amino acid metabolism to improve frost resistance and adaptability. The ket gene such as sucD and coaD in the energy metabolism and metabolic pathways, gapA1 and tpiA in glucose metabolism and energy balance, asd and gnd in the metabolic pathways of amino acid synthesis and protein synthesis, crtN in the context of protective mechanisms and stress response should be explored furthermore. In metabolomic research, the arginine synthesis pathway, biofilm formation pathway, Adenosine triphosphate-binding cassette transporters and other metabolic pathways deserve special attention and research. IMPORTANCEThis study highlights the importance of understanding the anti-freezing mechanisms of *Staphylococcus aureus* in frozen food safety. By analyzing proteomics, phosphorylated proteomics, and metabolomics, it identifies key pathways like energy metabolism, biofilm formation, and amino acid synthesis that enhance bacterial frost resistance, offering insights for improving food preservation and safety.

microbiology↗

AUTO-SP: automated sample preparation for analyzing proteins and protein modifications

Liquid chromatography (LC) tandem mass spectrometry (MS/MS) is one of the widely used proteomic techniques to study the alterations occurred at protein expression level as well as post-translation modifications (PTMs) of proteins that are relevant to different physiological or pathological statuses. The mass spectrometric analysis of peptides fragmented from proteins (bottom-up proteomics) has emerged as one of the major approaches for proteomics. In this approach, proteins are first cleaved into peptides for mass spectrometric analysis and peptides with PTMs are further enriched followed by the LC-MS/MS analysis. To achieve a reproducible and quantitative proteomic characterization, a well-established protease digestion and PTM peptide enrichment protocol is critical. In this study, we developed an automated sample preparation (AUTO-SP) for analyzing proteins and protein modifications utilizing Patient-Derived Xenograft (PDX) breast cancer tumors (basal-like and luminal subtypes). The protein amount was quantified and proteins were further digested by using AUTO-SP for each PDX sample. Based on the data-independent acquisition (DIA)-MS data, we observed samples of the same breast cancer subtypes were highly correlated (>0.98). Additionally, >14,000 ubiquitinated peptides were identified in the PDX samples when using AUTO-SP for ubiquitin enrichment, while unique pathways were enriched from the basal-like and luminal subtypes. AUTO-SP demonstrated its efficacy to provide reliable and reproducible sample preparation procedure for MS-based proteomic and PTM analyses.

systems biology↗

Multi-omic profiling of intraductal papillary neoplasms of the pancreas reveals distinct expression patterns and potential markers of progression

In order to advance our understanding of precancers in the pancreas, 69 pancreatic intraductal papillary neoplasms (IPNs), including 64 intraductal papillary mucinous neoplasms (IPMNs) and 5 intraductal oncocytic papillary neoplasms (IOPNs), 32 pancreatic cyst fluid samples, 104 invasive pancreatic ductal adenocarcinomas (PDACs), 43 normal adjacent tissues (NATs), and 76 macro-dissected normal pancreatic ducts (NDs) were analyzed by mass spectrometry. A total of 10,246 proteins and 22,284 glycopeptides were identified in all tissue samples, and 756 proteins with more than 1.5-fold increase in abundance in IPMNs relative to NDs were identified, 45% of which were also identified in cyst fluids. The over-expression of selected proteins was validated by immunolabeling. Proteins and glycoproteins overexpressed in IPMNs included those involved in glycan biosynthesis and the immune system. In addition, multiomics clustering identified two subtypes of IPMNs. This study provides a foundation for understanding tumor progression and targets for earlier detection and therapies. SignificanceThis multilevel characterization of intraductal papillary neoplasms of the pancreas provides a foundation for understanding the changes in protein and glycoprotein expression during the progression from normal duct to intraductal papillary neoplasm, and to invasive pancreatic carcinoma, providing a foundation for informed approaches to earlier detection and treatment.

cancer biology↗

Molecular mechanism of acid stress response of A. acidoterrestris DSM 3922T under sublethal pH environment

Acid-responsive proteome expression profiles of Alicyclobacillus acidoterrestris (A. acidoterrestris) were analysed using label-free quantitative mass spectrometry to investigate its acid resistance mechanism at sublethal pH. Totally, 325 differential expression proteins were identified during acid stress at pH2.5 condition for 15 min, of which the expressions of 83 proteins were up-regulated and the other 242 proteins expressions were down-regulated. Differentially expressed proteins were mainly involved in organic nitrogen compounds metabolism, small molecule metabolism, organic acid metabolism and signal transduction. Overall, they were mapped into 97 metabolic pathways. Combination of KEGG pathway analysis and protein functional analysis suggested that the pH homeostasis system, changes in metabolic pathways, cell membrane permeability and DNA repair are the main acid resistance mechanisms of A. acidoterrestris at sublethal pH conditions. It is speculated that A. acidoterrestris may sense and transmit pH signals from the external environment through the nhaB protein which holds histidine-dependent acid resistance system, initiating a series of acid tolerance reactions. Our study demonstrated global physiological response of A. acidoterrestris to sublethal pH, which provided a better understanding of acid adaption mechanism of A. acidoterrestris.

microbiology↗

Antibacterial mechanism of inosine against Alicyclobacillus acidoterrestris

Inosine could potentially become a novel antibacterial agent against A. acidoterrestris as low-dose of inosine can prevent A. acidoterrestris contamination. However, until now the antibacterial mechanism of inosine targeting A. acidoterrestris is still unknown. In this study, to unravel the mechanism of inosine against A. acidoterrestris puzzle, the effects of inosine on bacterial surface hydrophobicity, intracellular protein content, cell membrane damage extent and permeability of the A. acidoterrestris were investigated. The results showed that inosine can effectively inhibit the growth and reproduction of A. acidoterrestris by destroying the integrity of cell membrane and increasing its permeability, causing the leakage of intracellular nutrients. Furthermore, the interaction networks of inosine target proteins were analyzed. The interaction networks further revealed that damage of bacterial cell membrane might be relevant to inosines effect on bacterial DNA replication and cell energy metabolism through regulating nucleotide synthesis and metabolism and the activity of translation initiation factors. Finally, the antibacterial mechanism of inosine against A. acidoterrestris was proposed.

microbiology↗

An HBV mRNA vaccine with favorable virological suppression and superior immunity

BRIEF ABSTRACTHere we report on the development and comprehensive evaluations of an mRNA vaccine for chronic hepatitis B (CHB) treatment. In two different HBV carrier mouse models generated by viral vector-mediated HBV transfection (pAAV-HBV1.2 and rAAV8-HBV1.3), this vaccine demonstrates sufficient and persistent virological suppression, and robust immunogenicity in terms of induction of strong innate immune activation, high-level virus-specific antibodies, memory B cells and T cells. mRNA platform therefore holds prospects for therapeutic vaccine development to combat CHB.

immunology↗

A novel and effective Cre/lox-based genetic tool for repeated, targeted and markerless integration in Yarrowia lipolytica

The unconventional yeast Yarrowia lipolytica is extensively applied in bioproduction fields owing to its excellent metabolite and protein production ability. Nonetheless, utilization of this promising host is still restricted by limited availability of precise and effective gene integration tools. In this study, a novel and efficient genetic tool was developed for targeted, repeated, and markerless gene integration based on Cre/lox site-specific recombination system. The developed tool required only a single selection marker and could completely excise all of the unnecessary sequences. A total of three plasmids were created and seven rounds of marker-free gene integration were examined in Y. lipolytica. All the integration efficiencies remained above 90%, and analysis of protein production and growth characteristics of the engineered strains confirmed that genome modification via the novel genetic tool was feasible. Further work also confirmed the genetic tool was effective for integration of other genes, loci, and strains. Thus, this study significantly promotes the application of Cre/lox system and presents a powerful tool for genome engineering in Y. lipolytica. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=113 SRC="FIGDIR/small/424803v2_ufig1.gif" ALT="Figure 1"> View larger version (23K): org.highwire.dtl.DTLVardef@11b3be9org.highwire.dtl.DTLVardef@fa7e2aorg.highwire.dtl.DTLVardef@170fafaorg.highwire.dtl.DTLVardef@6d4750_HPS_FORMAT_FIGEXP M_FIG C_FIG The novel genetic tool comprised three plasmids, namely, Cre-Y1, Cre-Y2, and Cre-Y3. Cre-Y1 was introduced into the Upleu locus of Po1f, and then recombination between two lox71 sites could remove unnecessary plasmid elements and produce an initial strain harboring a lox71 site. Subsequently, Cre-Y2 was integrated onto the leu2 locus, forming a transitional strain with three lox sites (lox71, lox66, and rclox66). Recombination reactions among these three lox sites could excise unnecessary DNA fragments and retain a lox72 site, an rclox66 site, and a target gene expression cassette in the genome. Similarly, integration of Cre-Y3 produced strains harboring two target gene expression cassettes. Consequently, repeated, targeted, and markerless gene integration could be efficiently realized following iterative integration of Cre-Y2 and Cre-Y3. HighlightsO_LIA powerful genetic tool was developed for targeted and markerless gene integration C_LIO_LIThe genetic tool was effective for various genes, loci, and strains C_LIO_LIOnly a single selection marker was adequate for repeated gene integration C_LIO_LIAll of the useless and redundant sequences would be excised C_LIO_LIAll integration efficiencies could remain above 90% C_LI

synthetic biology↗

Enhanced inflammatory response mediated by parenchymal cells associates with resistance towards mTOR inhibition

Activation of the mTOR pathway is frequently found in cancer, but mTOR inhibitors have thus far failed to demonstrate significant antiproliferative efficacy in the majority of cancer types. Besides cancer cell-intrinsic resistance mechanisms, it is conceivable that mTOR inhibitors impact on non-malignant host cells in a manner that ultimately supports resistance of cancer cells. Against this background, we sought to analyze the functional consequences of mTOR inhibition in hepatocytes for the growth of metastatic colon cancer. To this end, we established a liver epithelial cell (LEC)-specific knock-out (KO) of mTOR (mTORLEC mice). We used these mice to characterize the growth of colorectal liver metastases with and without partial hepatectomy to model different clinical settings. While the LEC-specific loss of mTOR remained without effect on metastasis growth in intact liver, partial liver resection resulted in the formation of larger metastases in mTORLEC mice compared to wildtype controls. This was accompanied by significantly enhanced inflammatory activity in LEC-specific mTOR KO livers after partial liver resection. Analysis of NF-{kappa}B target gene expression and immunohistochemistry of p65 displayed a significant activation of NF-{kappa}B in mTORLEC mice, suggesting a functional importance of this pathway for the observed inflammatory phenotype. Taken together, we show an unexpected acceleration of liver metastases upon deletion of mTOR in liver epithelial cells. Our results support the notion that non-malignant host cells can contribute to resistance against mTOR inhibitors and encourage to test if anti-inflammatory drugs are able to improve the efficacy of mTOR inhibitor for cancer therapy.

cancer biology↗

Comparison of SARS-CoV-2 infections among 3 species of non-human primates

COVID-19, caused by SARS-CoV-2 infection, has recently been announced as a pandemic all over the world. Plenty of diagnostic, preventive and therapeutic knowledges have been enriched from clinical studies since December 2019. However, animal models, particularly non-human primate models, are urgently needed for critical questions that could not be answered in clinical patients, evaluations of anti-viral drugs and vaccines. In this study, two families of non-human primates, Old world monkeys (12 Macaca mulatta, 6 Macaca fascicularis) and New world monkeys (6 Callithrix jacchus), were experimentally inoculated with SARS-CoV-2. Clinical signs were recorded. Samples were collected for analysis of viral shedding, viremia and histopathological examination. Increased body temperature was observed in 100% (12/12) M. mulatta, 33.3% (2/6) M. fascicularis and none (0/6) of C. jacchus post inoculation of SARS-CoV-2. All of M. mulatta and M. fascicularis showed chest radiographic abnormality. Viral genomes were detected in nasal swabs, throat swabs, anal swabs and blood from all 3 species of monkeys. Viral shedding from upper respiratory samples reached the peak between day 6 and day 8 post inoculation. From necropsied M. mulatta and M. fascicularis, the tissues showing virus positive were mainly lung, weasand, bronchus and spleen. No viral genome was seen in any of tissues from 2 necropsied C. jacchus. Severe gross lesions and histopathological changes were observed in lung, heart and stomach of SARS-CoV-2 infected animals. In summary, we have established a NHP model for COVID-19, which could be used to evaluate drugs and vaccines, and investigate viral pathogenesis. M. mulatta is the most susceptible to SARS-CoV-2 infection, followed by M. fascicularis and C. jacchus. One Sentence SummaryM. mulatta is the most susceptible to SARS-CoV-2 infection as compared to M. fascicularis and C. jacchus.

microbiology↗

LncRNA and predictive model to improve the diagnosis of clinically diagnosed pulmonary tuberculosis

BackgroundClinically diagnosed pulmonary tuberculosis (PTB) patients lack Mycobacterium tuberculosis (MTB) microbiologic evidence, and misdiagnosis or delayed diagnosis often occurs as a consequence. We investigated the potential of lncRNAs and corresponding predictive models to diagnose these patients. MethodsWe enrolled 1372 subjects, including clinically diagnosed PTB patients, non-TB disease controls and healthy controls, in three cohorts (Screening, Selection and Validation). Candidate lncRNAs differentially expressed in blood samples of the PTB and healthy control groups were identified by microarray and qRT-PCR in the Screening Cohort. Logistic regression models were developed using lncRNAs and/or electronic health records (EHRs) from clinically diagnosed PTB patients and non-TB disease controls in the Selection Cohort. These models were evaluated by AUC and decision curve analysis, and the optimal model was presented as a Web-based nomogram, which was evaluated in the Validation Cohort. The biological function of lncRNAs was interrogated using ELISA, lactate dehydrogenase release analysis and flow cytometry. ResultsThree differentially expressed lncRNAs (ENST00000497872, n333737, n335265) were identified. The optimal model (i.e., nomogram) incorporated these three lncRNAs and six EHR variables (age, hemoglobin, weight loss, low-grade fever, CT calcification and TB-IGRA). The nomogram showed an AUC of 0.89, sensitivity of 0.86 and specificity of 0.82 in the Validation Cohort, which demonstrated better discrimination and clinical net benefit than the EHR model. ENST00000497872 may regulate inflammatory cytokine production, cell death and apoptosis during MTB infection. ConclusionsLncRNAs and the user-friendly nomogram could facilitate the early identification of PTB cases among suspected patients with negative MTB microbiologic evidence.

molecular biology↗

Autophagy determines osimertinib resistance through regulation of stem cell-like properties in EGFR-mutant lung cancer

Drug resistance to Osimertinib, a 3rd-generation EGFR-TKI is inevitable. Autophagy plays a contradictory role in resistance of 1st and 2nd generation EGFR-TKI, and its significance in osimertinib resistance is much less clear. We therefore investigated whether autophagy determines osimertinib resistance. First, osimertinib induced autophagy to a much greater extent than that of gefitinib, and autophagy inhibition further increased osimertinib efficacy. Next, enhanced autophagy was found in osimertinib resistant cells and autophagy inhibition partially reversed osimertinib resistance. Enhanced stem-cell like properties were found in resistant cells, and siRNA-knock down of SOX2 or ALDH1A1reversed osimertinib resistance. Of note, autophagy inhibition or siRNA-knock down of Beclin-1 decreased expression of SOX2 and ALDH1A1 and stem-cell like properties. Next, autophagy inhibition and osimertinib in combination effectively blocked tumor growth in xenografts, which was associated with decreased autophagy and stem cell-like properties in vivo. Finally, enhanced autophagy was found in lung cancer patients with resistance to osimertinib. In conclusion, the current study delineates a previously unknown function of autophagy in determining osimertinib resistance through promoting stem-cell like properties.

cancer biology↗