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1.
Curr Res Toxicol ; 7: 100184, 2024.
Article in English | MEDLINE | ID: mdl-39285937

ABSTRACT

Croton oil is liquid at room temperature, with a pale-yellow color and spicy odor. It is commonly used in combination with phenol as a chemical peeling agent in dermatology, which reveals its caustic exfoliating effects. Topical use of croton oil at a high dose produces skin irritation, inflammation, swelling, pain, and even tumors. Therefore, croton oil has been widely used for inflammation, pain, and tumor related research, with different animal models having been established. However, mechanistic studies through which croton oil induces skin swelling, injury and activates tissue repair/regeneration are limited. The present study used croton oil to induce mouse ear edema and examined tissue responses 4 h after exposure. To this end, croton oil was applied to the ventral side of mouse ears, followed by tissue collection. Samples were analyzed by hematoxylin and eosin (H&E) staining, toluidine blue staining, and immunohistochemistry staining for myeloperoxidase (MPO) and matrix metalloproteinase-9 (MMP-9). Western blotting and ELISA were also carried out for MMP-9 together with unbiased proteomic analysis using mass-spectrometry. Results from our study demonstrated that as soon as 4 h of exposure to 2.5 % croton oil, the expression levels of MPO and MMP-9 in the dermis significantly increased compared to acetone-treated (vehicle) control ears, as did other inflammatory reactions such as swelling and neutrophil aggregation and infiltration. Subsequently, proteomic analysis confirmed that croton oil treatment resulted in significant upregulation of proteins such as myeloperoxidase (MPO), matrix metalloproteinase-9 (MMP-9), and matrix metalloproteinase-8 (MMP-8) in the ear skin. Interestingly, mouse ears treated with acetone vehicle showed differential expression of 2,478 proteins relative to naïve tissues; among those differentially expressed in acetone-treated samples were members of the phosphatidylinositol-glycan biosynthesis class N, T and U proteins (PIGN, PIGT, and PIGU). Overall, this work confirms the presence of neutrophil-derived MPO and MMP-9 and extends the body of knowledge to show that MMP-8 is also present during croton oil-mediated skin inflammation in the mouse ear; moreover, we find that acetone vehicle is not inert and has effects on the skin that should be considered moving forward.

2.
Sci Adv ; 10(32): eadl1584, 2024 Aug 09.
Article in English | MEDLINE | ID: mdl-39110797

ABSTRACT

Histone acetyltransferases KAT2A and KAT2B are paralogs highly expressed in the intestinal epithelium, but their functions are not well understood. In this study, double knockout of murine Kat2 genes in the intestinal epithelium was lethal, resulting in robust activation of interferon signaling and interferon-associated phenotypes including the loss of intestinal stem cells. Use of pharmacological agents and sterile organoid cultures indicated a cell-intrinsic double-stranded RNA trigger for interferon signaling. Acetyl-proteomics and sequencing of immunoprecipitated double-stranded RNA were used to interrogate the mechanism behind this response, which identified mitochondria-encoded double-stranded RNA as the source of intrinsic interferon signaling. Kat2a and Kat2b therefore play an essential role in regulating mitochondrial functions and maintaining intestinal health.


Subject(s)
Histone Acetyltransferases , Interferons , Mice, Knockout , RNA, Double-Stranded , Signal Transduction , Stem Cells , Animals , RNA, Double-Stranded/metabolism , Mice , Stem Cells/metabolism , Stem Cells/cytology , Interferons/metabolism , Histone Acetyltransferases/metabolism , Histone Acetyltransferases/genetics , Intestinal Mucosa/metabolism , Intestinal Mucosa/cytology , Mitochondria/metabolism , Cell Self Renewal/genetics , Intestines/cytology
3.
bioRxiv ; 2024 May 12.
Article in English | MEDLINE | ID: mdl-38766142

ABSTRACT

Circadian clocks respond to temperature changes over the calendar year, allowing organisms to adjust their daily biological rhythms to optimize health and fitness. In Drosophila, seasonal adaptations and temperature compensation are regulated by temperature-sensitive alternative splicing (AS) of period (per) and timeless (tim) genes that encode key transcriptional repressors of clock gene expression. Although clock (clk) gene encodes the critical activator of clock gene expression, AS of its transcripts and its potential role in temperature regulation of clock function have not been explored. We therefore sought to investigate whether clk exhibits AS in response to temperature and the functional changes of the differentially spliced transcripts. We observed that clk transcripts indeed undergo temperature-sensitive AS. Specifically, cold temperature leads to the production of an alternative clk transcript, hereinafter termed clk-cold, which encodes a CLK isoform with an in-frame deletion of four amino acids proximal to the DNA binding domain. Notably, serine 13 (S13), which we found to be a CK1α-dependent phosphorylation site, is among the four amino acids deleted in CLK-cold protein. Using a combination of transgenic fly, tissue culture, and in vitro experiments, we demonstrated that upon phosphorylation at CLK(S13), CLK-DNA interaction is reduced, thus decreasing CLK occupancy at clock gene promoters. This is in agreement with our findings that CLK occupancy at clock genes and transcriptional output are elevated at cold temperature, which can be explained by the higher amounts of CLK-cold isoforms that lack S13 residue. This study provides new insights into the complex collaboration between AS and phospho-regulation in shaping temperature responses of the circadian clock.

4.
J Nutr Health Aging ; 28(6): 100223, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38598978

ABSTRACT

OBJECTIVES: Previous studies suggested protective associations of vegetables and fruits (VF) intake with cognitive function, but evidence on specific types of VF was insufficient. METHODS: The current study included 4066 participants from 1997 to 2006 in the China Health and Nutrition Survey (CHNS) and 6170 participants from 2013 to 2020 in the Health and Retirement Study (HRS). Dietary intake (using 3-day 24-h dietary recalls in CHNS and food frequency questionnaire in HRS) and cognitive function (using the Telephone Interview for Cognitive Status-Modified, TICS-m) were measured. Linear mixed-effects models were used to estimate the beta coefficients (ß) and the 95% confidence intervals (CI) to evaluate the association of VF with cognitive function (z-score) and its decline. RESULTS: Highest intake of total VF was associated with better cognitive function and slower cognitive decline. Differences in cognitive function z-score between the highest and lowest tertiles of VF consumption were 0.039 (95% CI: 0.002, 0.076) for CHNS and 0.063 (95% CI: 0.026, 0.100) for HRS. The corresponding differences in annual cognitive decline were 0.011 (95% CI: 0.002, 0.021) and 0.012 (95% CI: 0.003, 0.020) units respectively. Vegetables and fruits showed independent associations with cognitive function and its decline. In specific VF subgroups, when comparing the highest to the lowest tertile intake, cruciferous vegetables (ß = 0.058, 95% CI: 0.017, 0.100 in CHNS and ß = 0.067, 95% CI: 0.032, 0.101 in HRS) and green leafy vegetables (ß = 0.036, 95% CI: -0.001, 0.073 in CHNS and ß = 0.082, 95% CI: 0.046, 0.117 in HRS) was associated with better cognitive function in both cohorts. Similarly, higher intake of dark-colored vegetables (ß = 0.019, 95% CI: 0.008, 0.030 for red/yellow vegetables in CHNS and ß = 0.004, 95% CI: 0.001, 0.007 for green leafy vegetables in HRS) were associated with slower cognitive decline in subsequent years. Moreover, rigorous sensitivity analyses confirmed the stability of the results. CONCLUSIONS: Our findings support the potential beneficial roles of VF, especially cruciferous vegetables, green leafy vegetables, and red/yellow vegetables, in maintaining cognitive function and slowing cognitive decline in middle-aged and older adults.


Subject(s)
Cognition , Cognitive Dysfunction , Diet , Fruit , Vegetables , Humans , Female , Male , Cognition/physiology , Longitudinal Studies , Middle Aged , Aged , China , Diet/statistics & numerical data , Nutrition Surveys
5.
Biochem Biophys Res Commun ; 710: 149881, 2024 May 28.
Article in English | MEDLINE | ID: mdl-38583233

ABSTRACT

Maackia amurensis lectins serve as research and botanical agents that bind to sialic residues on proteins. For example, M. amurensis seed lectin (MASL) targets the sialic acid modified podoplanin (PDPN) receptor to suppress arthritic chondrocyte inflammation, and inhibit tumor cell growth and motility. However, M. amurensis lectin nomenclature and composition are not clearly defined. Here, we sought to definitively characterize MASL and its effects on tumor cell behavior. We utilized SDS-PAGE and LC-MS/MS to find that M. amurensis lectins can be divided into two groups. MASL is a member of one group which is composed of subunits that form dimers, evidently mediated by a cysteine residue in the carboxy region of the protein. In contrast to MASL, members of the other group do not dimerize under nonreducing conditions. These data also indicate that MASL is composed of 4 isoforms with an identical amino acid sequence, but unique glycosylation sites. We also produced a novel recombinant soluble human PDPN receptor (shPDPN) with 17 threonine residues glycosylated with sialic acid moieties with potential to act as a ligand trap that inhibits OSCC cell growth and motility. In addition, we report here that MASL targets PDPN with very strong binding kinetics in the nanomolar range. Moreover, we confirm that MASL can inhibit the growth and motility of human oral squamous cell carcinoma (OSCC) cells that express the PDPN receptor. Taken together, these data characterize M. amurensis lectins into two major groups based on their intrinsic properties, clarify the composition of MASL and its subunit isoform sequence and glycosylation sites, define sialic acid modifications on the PDPN receptor and its ability to act as a ligand trap, quantitate MASL binding to PDPN with KD in the nanomolar range, and verify the ability of MASL to serve as a potential anticancer agent.


Subject(s)
Antineoplastic Agents , Carcinoma, Squamous Cell , Head and Neck Neoplasms , Mouth Neoplasms , Humans , Carcinoma, Squamous Cell/pathology , Squamous Cell Carcinoma of Head and Neck , N-Acetylneuraminic Acid/metabolism , Maackia/chemistry , Maackia/metabolism , Mouth Neoplasms/pathology , Chromatography, Liquid , Ligands , Tandem Mass Spectrometry , Lectins/pharmacology , Antineoplastic Agents/pharmacology , Sequence Analysis , Cell Movement
6.
Curr Issues Mol Biol ; 46(3): 2480-2496, 2024 Mar 14.
Article in English | MEDLINE | ID: mdl-38534773

ABSTRACT

In the present work, we evaluated the antifungal activities of two novel ebselen analogs, N-allyl-benzisoselenazol-3(2H)-one (N-allyl-bs) and N-3-methylbutylbenzisoselenazol-3(2H)-one (N-3mb-bs). Colorimetric and turbidity assays were performed to determine the minimum inhibitory concentration (MIC) of these compounds in S1 (fluconazole-sensitive) and S2 (fluconazole-resistant) strains of C. albicans. N-3mb-bs was more active than the N-allyl-bs compound. It is noteworthy that the concentration of N-3mb-bs observed to inhibit fungal growth by 50% (18.2 µM) was similar to the concentration observed to inhibit the activity of the yeast plasma membrane H+-ATPase (Pma1p) by 50% (19.6 µM). We next implemented a mouse model of vulvovaginal candidiasis (VVC) using the S1 strain and examined the mouse and yeast proteins present in the vaginal lavage fluid using proteomics. The yeast proteins detected were predominately glycolytic enzymes or virulence factors associated with C. albicans while the mouse proteins present in the lavage fluid included eosinophil peroxidase, desmocollin-1, and gasdermin-A. We then utilized the N-3mb-bs compound (12.5 mg/kg) in the mouse VVC model and observed that it significantly reduced the vaginal fungal burden, histopathological changes in vagina tissue, and expression of myeloperoxidase (MPO). All in all, the present work has identified a potentially promising drug candidate for VVC treatment.

7.
Psychol Health Med ; 29(2): 362-374, 2024.
Article in English | MEDLINE | ID: mdl-37899648

ABSTRACT

The COVID-19 pandemic exposed the public to enormous health risks and induced wide-ranging impacts on people's mental health. Post-traumatic growth is a possible psychological benefits that may occur during struggling with the COVID-19 pandemic. This research explored 1) demographics differences on risk perception of COVID-19 pandemic, engagement in health-protective behavior and post-traumatic growth during the COVID-19 pandemic; and 2) the mediation effect of engaging in health-protective behaviors between risk perception and post-traumatic growth during the COVID-19 pandemic. Females showed a significant higher level of engagement in health-protective behaviors. People who were married reported a significantly higher level of risk perception, engagement in health-protective behavior and post-traumatic growth than those who were in other marital status (i.e. single, divorced, widowed). People who had acquaintances being infected with COVID-19 reported significant higher level of risk perception and engagement in health-protective behaviors. Engagement in health-protective behaviors mediated the relationship between risk perception and post-traumatic growth. Implications of the results for public health interventions are discussed.


Subject(s)
COVID-19 , Posttraumatic Growth, Psychological , Female , Humans , Pandemics/prevention & control , China/epidemiology , Perception
8.
Environ Pollut ; 338: 122681, 2023 Dec 01.
Article in English | MEDLINE | ID: mdl-37802288

ABSTRACT

Sulfonamide (SA) is an emerging contaminants and the efficient treatment of SA containing wastewater remains a challenge. Herein, SA degradation by gamma irradiation has been systematacially studied. SA (10 mg/L) could be totally removed with 1.5 kGy irradiation. Quenching experiments demonstrated that •OH and eaq- were the predominant for SA degradation. SA degradation was reduced with initial concentration increasing, and the removal was faster with pH increasing in the range of 3.1-10.8. The coexisting matters affected SA degradation through changing reactive species, and the introduction of SO42- and Cl- enhanced SA degradation, while CO32- had a negative impact on SA degradation, and the degradation was insignificantly affected when adding humic acid. Gamma irradiation could remain effective in real water matrixes. In conjunction with LC-MS analysis and DFT calculation, possible degradation pathways for SA were proposed. Gamma irradiation could reduce the toxicity of SA, while several byproducts with more toxic were also formed. Furthermore, gamma/priodate (PI) process was promising to enhance SA degradation and mineralization. k value increased by 1.85 times, and mineralization rate increased from 19.51% to 79.19% when adding PI. This study suggested that ionizing radiation was efficient to eliminate SA in wastewater.


Subject(s)
Water Pollutants, Chemical , Water Purification , Sulfanilamide , Wastewater , Water Pollutants, Chemical/radiation effects , Radiation, Ionizing , Sulfonamides , Water , Oxidation-Reduction
9.
bioRxiv ; 2023 Sep 05.
Article in English | MEDLINE | ID: mdl-37732252

ABSTRACT

Histone acetyltransferases KAT2A and KAT2B are paralogs highly expressed in the intestinal epithelium, but their functions are not well understood. In this study, double knockout of murine Kat2 genes in the intestinal epithelium was lethal, resulting in robust activation of interferon signaling and interferon-associated phenotypes including the loss of intestinal stem cells. Use of pharmacological agents and sterile organoid cultures indicated a cell-intrinsic double-stranded RNA trigger for interferon signaling. Acetyl-proteomics and dsRIP-seq were employed to interrogate the mechanism behind this response, which identified mitochondria-encoded double-stranded RNA as the source of intrinsic interferon signaling. Kat2a and Kat2b therefore play an essential role in regulating mitochondrial functions as well as maintaining intestinal health.

10.
Am J Clin Nutr ; 118(1): 174-182, 2023 07.
Article in English | MEDLINE | ID: mdl-37105521

ABSTRACT

BACKGROUND: Evidence on the association of the Mediterranean-Dietary Approaches to Stop Hypertension Intervention for Neurodegenerative Delay (MIND) diet with cognitive aging is limited and inconsistent. OBJECTIVES: We examined how the MIND diet is related to cognitive function and its decline among middle-aged and older adults. METHODS: We included 4066 participants with baseline dietary assessment and ≥1 cognitive test from the China Health and Nutrition Survey in 1997, 2000, 2004, and 2006, with a median follow-up of 3 y. The modified MIND diet score (range: 0-12) was calculated based on 9 healthy and 3 unhealthy food groups. Linear mixed-effect models were used to examine the association of adherence to the MIND diet with z-scores of cognitive function and cognitive decline. We also conducted a meta-analysis including our findings and 7 other cohort studies. RESULTS: At baseline, the median MIND diet scores across increasing tertile were 3.0, 4.0, and 5.5, respectively. Participants with higher MIND diet scores had better global cognitive function. The adjusted difference in global cognitive function z-score for every 3-point increment of MIND diet scores was 0.110 [95% confidence interval (CI), 0.060, 0.159, P-trend < 0.001], which was approximately equivalent to being 1 y younger in age. Consumption of nuts, fish, red meats, and tea showed independent positive associations with cognitive function, while fried food consumption exhibited inverse associations. In the meta-analysis of 26,103 participants, one standardized deviation increment of the MIND score was associated with 0.042 (95% CI: 0.020, 0.065) units higher in global cognitive function z-score and 0.010 (95% CI: -0.001, 0.021) units slower in annual cognitive decline. CONCLUSIONS: Our findings suggest that higher adherence to the MIND diet was associated with better cognitive function and potentially slower cognitive decline in later life. Further large-scale observational and interventional studies are warranted to elucidate the cognitive effects of the MIND diet. This meta-analysis was registered at PROSPERO as CRD42022330417.


Subject(s)
Cognitive Dysfunction , Diet, Mediterranean , Dietary Approaches To Stop Hypertension , Animals , Humans , Prospective Studies , Cohort Studies , Cognitive Dysfunction/prevention & control , Cognition
11.
Blood Cancer Discov ; 4(1): 12-33, 2023 01 06.
Article in English | MEDLINE | ID: mdl-36322781

ABSTRACT

T-cell acute lymphoblastic leukemia (T-ALL) is a NOTCH1-driven disease in need of novel therapies. Here, we identify a NOTCH1-SIRT1-KAT7 link as a therapeutic vulnerability in T-ALL, in which the histone deacetylase SIRT1 is overexpressed downstream of a NOTCH1-bound enhancer. SIRT1 loss impaired leukemia generation, whereas SIRT1 overexpression accelerated leukemia and conferred resistance to NOTCH1 inhibition in a deacetylase-dependent manner. Moreover, pharmacologic or genetic inhibition of SIRT1 resulted in significant antileukemic effects. Global acetyl proteomics upon SIRT1 loss uncovered hyperacetylation of KAT7 and BRD1, subunits of a histone acetyltransferase complex targeting H4K12. Metabolic and gene-expression profiling revealed metabolic changes together with a transcriptional signature resembling KAT7 deletion. Consistently, SIRT1 loss resulted in reduced H4K12ac, and overexpression of a nonacetylatable KAT7-mutant partly rescued SIRT1 loss-induced proliferation defects. Overall, our results uncover therapeutic targets in T-ALL and reveal a circular feedback mechanism balancing deacetylase/acetyltransferase activation with potentially broad relevance in cancer. SIGNIFICANCE: We identify a T-ALL axis whereby NOTCH1 activates SIRT1 through an enhancer region, and SIRT1 deacetylates and activates KAT7. Targeting SIRT1 shows antileukemic effects, partly mediated by KAT7 inactivation. Our results reveal T-ALL therapeutic targets and uncover a rheostat mechanism between deacetylase/acetyltransferase activities with potentially broader cancer relevance. This article is highlighted in the In This Issue feature, p. 1.


Subject(s)
Leukemia, T-Cell , Precursor T-Cell Lymphoblastic Leukemia-Lymphoma , Humans , Signal Transduction , Receptor, Notch1/genetics , Precursor T-Cell Lymphoblastic Leukemia-Lymphoma/drug therapy , Precursor T-Cell Lymphoblastic Leukemia-Lymphoma/genetics , Sirtuin 1/genetics , Sirtuin 1/metabolism , Sirtuin 1/pharmacology , Acetyltransferases/metabolism , Acetyltransferases/pharmacology , Acetyltransferases/therapeutic use , Histone Acetyltransferases/metabolism , Histone Acetyltransferases/pharmacology , Histone Acetyltransferases/therapeutic use
12.
Mol Carcinog ; 61(7): 677-689, 2022 07.
Article in English | MEDLINE | ID: mdl-35472679

ABSTRACT

The Src tyrosine kinase is a strong tumor promotor. Over a century of research has elucidated fundamental mechanisms that drive its oncogenic potential. Src phosphorylates effector proteins to promote hallmarks of tumor progression. For example, Src associates with the Cas focal adhesion adaptor protein to promote anchorage independent cell growth. In addition, Src phosphorylates Cas to induce Pdpn expression to promote cell migration. Pdpn is a transmembrane receptor that can independently increase cell migration in the absence of oncogenic Src kinase activity. However, to our knowledge, effects of Src kinase activity on anchorage independent cell growth and migration have not been examined in the absence of Pdpn expression. Here, we analyzed the effects of an inducible Src kinase construct in knockout cells with and without exogenous Pdpn expression on cell morphology migration and anchorage independent growth. We report that Src promoted anchorage independent cell growth in the absence of Pdpn expression. In contrast, Src was not able to promote cell migration in the absence of Pdpn expression. In addition, continued Src kinase activity was required for cells to assume a transformed morphology since cells reverted to a nontransformed morphology upon cessation of Src kinase activity. We also used phosphoproteomic analysis to identify 28 proteins that are phosphorylated in Src transformed cells in a Pdpn dependent manner. Taken together, these data indicate that Src utilizes Pdpn to promote transformed cell growth and motility in complementary, but parallel, as opposed to serial, pathways.


Subject(s)
Neoplasms , src-Family Kinases , Cell Adhesion , Cell Movement , Humans , Phosphorylation , src-Family Kinases/genetics , src-Family Kinases/metabolism
13.
Curr Biol ; 31(3): 502-514.e7, 2021 02 08.
Article in English | MEDLINE | ID: mdl-33217322

ABSTRACT

Circadian clocks orchestrate daily rhythms in organismal physiology and behavior to promote optimal performance and fitness. In Drosophila, key pacemaker proteins PERIOD (PER) and TIMELESS (TIM) are progressively phosphorylated to perform phase-specific functions. Whereas PER phosphorylation has been extensively studied, systematic analysis of site-specific TIM phosphorylation is lacking. Here, we identified phosphorylation sites of PER-bound TIM by mass spectrometry, given the importance of TIM as a modulator of PER function in the pacemaker. Among the 12 TIM phosphorylation sites we identified, at least two of them are critical for circadian timekeeping as mutants expressing non-phosphorylatable mutations exhibit altered behavioral rhythms. In particular, we observed that CK2-dependent phosphorylation of TIM(S1404) promotes nuclear accumulation of PER-TIM heterodimers by inhibiting the interaction of TIM and nuclear export component, Exportin 1 (XPO1). We propose that proper level of nuclear PER-TIM accumulation is necessary to facilitate kinase recruitment for the regulation of daily phosphorylation rhythm and phase-specific transcriptional activity of CLOCK (CLK). Our results highlight the contribution of phosphorylation-dependent nuclear export of PER-TIM heterodimers to the maintenance of circadian periodicity and identify a new mechanism by which the negative elements of the circadian clock (PER-TIM) regulate the positive elements (CLK-CYC). Finally, because the molecular phenotype of tim(S1404A) non-phosphorylatable mutant exhibits remarkable similarity to that of a mutation in human timeless that underlies familial advanced sleep phase syndrome (FASPS), our results revealed an unexpected parallel between the functions of Drosophila and human TIM and may provide new insights into the molecular mechanisms underlying human FASPS.


Subject(s)
Circadian Rhythm , Active Transport, Cell Nucleus , Animals , CLOCK Proteins , Drosophila Proteins/genetics , Drosophila Proteins/metabolism , Drosophila melanogaster/genetics , Drosophila melanogaster/metabolism , Humans , Sleep Disorders, Circadian Rhythm
14.
Planta ; 252(4): 60, 2020 Sep 22.
Article in English | MEDLINE | ID: mdl-32964359

ABSTRACT

MAIN CONCLUSION: AS events affect genes encoding protein domain composition and make the single gene produce more proteins with a certain number of genes to satisfy the establishment of photosynthesis during de-etiolation. The drastic switch from skotomorphogenic to photomorphogenic development is an excellent system to elucidate rapid developmental responses to environmental stimuli in plants. To decipher the effects of different light wavelengths on de-etiolation, we illuminated etiolated maize seedlings with blue, red, blue-red mixed and white light, respectively. We found that blue light alone has the strongest effect on photomorphogenesis and that this effect can be attributed to the higher number and expression levels of photosynthesis and chlorosynthesis proteins. Deep sequencing-based transcriptome analysis revealed gene expression changes under different light treatments and a genome-wide alteration in alternative splicing (AS) profiles. We discovered 41,188 novel transcript isoforms for annotated genes, which increases the percentage of multi-exon genes with AS to 63% in maize. We provide peptide support for all defined types of AS, especially retained introns. Further in silico prediction revealed that 58.2% of retained introns have changes in domains compared with their most similar annotated protein isoform. This suggests that AS acts as a protein function switch allowing rapid light response through the addition or removal of functional domains. The richness of novel transcripts and protein isoforms also demonstrates the potential and importance of integrating proteomics into genome annotation in maize.


Subject(s)
Alternative Splicing , Seedlings , Transcriptome , Zea mays , Alternative Splicing/genetics , Etiolation/genetics , Gene Expression Regulation, Plant , Light , Proteome , Seedlings/genetics , Zea mays/genetics
15.
Sci Total Environ ; 747: 141533, 2020 Dec 10.
Article in English | MEDLINE | ID: mdl-32795806

ABSTRACT

Oxygen vacancies and Ti3+ defects in anatase TiO2 have attracted great attention to address the insufficient optical absorption and photoinduced charge-carrier separation in photocatalysis. In this study, we demonstrate a superficial and innovative approach for synthesizing anatase TiO2 nanoparticles with abundant oxygen vacancies via γ-ray irradiation reduction at room temperature. X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR) confirm that oxygen vacancies and Ti3+ defects can be quantitatively and extensively obtained by merely regulating the irradiation dosage. Photoelectrochemical measurements suggest that oxygen vacancies and Ti3+ defects promoted the separation of electron-hole pairs and then enhanced the photocatalytic degradation performance for organic pollutant. In comparison with TiO2 (no irradiation), the sample (49.5 kGy irradiation) exhibited a 20.0-fold enhancement in visible-light decomposition of phenol. In addition, the results of scavenge experiments and mechanism analysis revealed that O2- are the dominant active species. The excited electrons generated at the conduction band and oxygen vacancy level of TiO2-x-49.5 conspicuously contributes to generate much more ·O2- species. This novel study shows at room temperature, the γ-ray approach of irradiation leads to faster formation and quantification of oxygen vacancies in the semiconductor materials.

17.
J Proteome Res ; 19(4): 1718-1730, 2020 04 03.
Article in English | MEDLINE | ID: mdl-32134668

ABSTRACT

Knowledge of intracellular location can provide important insights into the function of proteins and their respective organelles, and there is interest in combining classical subcellular fractionation with quantitative mass spectrometry to create global cellular maps. To evaluate mass spectrometric approaches specifically for this application, we analyzed rat liver differential centrifugation and Nycodenz density gradient subcellular fractions by tandem mass tag (TMT) isobaric labeling with reporter ion measurement at the MS2 and MS3 level and with two different label-free peak integration approaches, MS1 and data independent acquisition (DIA). TMT-MS2 provided the greatest proteome coverage, but ratio compression from contaminating background ions resulted in a narrower accurate dynamic range compared to TMT-MS3, MS1, and DIA, which were similar. Using a protein clustering approach to evaluate data quality by assignment of reference proteins to their correct compartments, all methods performed well, with isobaric labeling approaches providing the highest quality localization. Finally, TMT-MS2 gave the lowest percentage of missing quantifiable data when analyzing orthogonal fractionation methods containing overlapping proteomes. In summary, despite inaccuracies resulting from ratio compression, data obtained by TMT-MS2 assigned protein localization as well as other methods but achieved the highest proteome coverage with the lowest proportion of missing values.


Subject(s)
Proteome , Proteomics , Animals , Ions , Mass Spectrometry , Rats
18.
Mol Cell Proteomics ; 18(11): 2244-2261, 2019 11.
Article in English | MEDLINE | ID: mdl-31501224

ABSTRACT

Treatments are emerging for the neuronal ceroid lipofuscinoses (NCLs), a group of similar but genetically distinct lysosomal storage diseases. Clinical ratings scales measure long-term disease progression and response to treatment but clinically useful biomarkers have yet to be identified in these diseases. We have conducted proteomic analyses of brain and cerebrospinal fluid (CSF) from mouse models of the most frequently diagnosed NCL diseases: CLN1 (infantile NCL), CLN2 (classical late infantile NCL) and CLN3 (juvenile NCL). Samples were obtained at different stages of disease progression and proteins quantified using isobaric labeling. In total, 8303 and 4905 proteins were identified from brain and CSF, respectively. We also conduced label-free analyses of brain proteins that contained the mannose 6-phosphate lysosomal targeting modification. In general, we detect few changes at presymptomatic timepoints but later in disease, we detect multiple proteins whose expression is significantly altered in both brain and CSF of CLN1 and CLN2 animals. Many of these proteins are lysosomal in origin or are markers of neuroinflammation, potentially providing clues to underlying pathogenesis and providing promising candidates for further validation.


Subject(s)
Aminopeptidases/physiology , Biomarkers/blood , Biomarkers/cerebrospinal fluid , Brain/metabolism , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/physiology , Lysosomes/metabolism , Membrane Glycoproteins/physiology , Molecular Chaperones/physiology , Neuronal Ceroid-Lipofuscinoses/diagnosis , Serine Proteases/physiology , Thiolester Hydrolases/physiology , Animals , Disease Models, Animal , Female , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Neuronal Ceroid-Lipofuscinoses/blood , Neuronal Ceroid-Lipofuscinoses/cerebrospinal fluid , Proteome/analysis , Tripeptidyl-Peptidase 1
19.
Genomics Proteomics Bioinformatics ; 17(6): 603-622, 2019 12.
Article in English | MEDLINE | ID: mdl-32179194

ABSTRACT

The ubiquitin system is crucial for the development and fitness of higher plants. De-etiolation, during which green plants initiate photomorphogenesis and establish autotrophy, is a dramatic and complicated process that is tightly regulated by a massive number of ubiquitylation/de-ubiquitylation events. Here we present site-specific quantitative proteomic data for the ubiquitylomes of de-etiolating seedling leaves of Zea mays L. (exposed to light for 1, 6, or 12 h) achieved through immunoprecipitation-based high-resolution mass spectrometry (MS). Through the integrated analysis of multiple ubiquitylomes, we identified and quantified 1926 unique ubiquitylation sites corresponding to 1053 proteins. We analyzed these sites and found five potential ubiquitylation motifs, KA, AXK, KXG, AK, and TK. Time-course studies revealed that the ubiquitylation levels of 214 sites corresponding to 173 proteins were highly correlated across two replicate MS experiments, and significant alterations in the ubiquitylation levels of 78 sites (fold change >1.5) were detected after de-etiolation for 12 h. The majority of the ubiquitylated sites we identified corresponded to substrates involved in protein and DNA metabolism, such as ribosomes and histones. Meanwhile, multiple ubiquitylation sites were detected in proteins whose functions reflect the major physiological changes that occur during plant de-etiolation, such as hormone synthesis/signaling proteins, key C4 photosynthetic enzymes, and light signaling proteins. This study on the ubiquitylome of the maize seedling leaf is the first attempt ever to study the ubiquitylome of a C4 plant and provides the proteomic basis for elucidating the role of ubiquitylation during plant de-etiolation.


Subject(s)
Etiolation , Proteomics , Seedlings/growth & development , Seedlings/metabolism , Ubiquitination , Zea mays/growth & development , Zea mays/metabolism , Kinetics , Ubiquitin/metabolism
20.
Sci Total Environ ; 645: 267-276, 2018 Dec 15.
Article in English | MEDLINE | ID: mdl-30029108

ABSTRACT

In this work, we describe a flocculation performance evaluation of a novel anionic polyacrylamide (APAM) synthesized using low dose γ-ray initiation. The APAM structure and morphology were characterized using Fourier transform-infrared spectroscopy (FTIR), High performance liquid chromatography (HPLC), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) techniques. In comparison to commercially purchased APAM (Mw = 1.0 × 107), γ-ray initiation was demonstrated to be a more effective method to increase molecular weight, decrease the residual acrylamide monomer, and improve thermal stability. Flocculant performance was evaluated by assessing their ability to remove Cd(II) from water. We utilized the Plackett-Burman (PB), steepest ascent, and response surface methodology (RSM) experimental design to identify the optimal flocculating conditions for the removal of soluble Cd(II). Under optimal conditions [26.84 mg L-1 CaO, 71.28 mg L-1 polyaluminium chloride (PAC) and 2.87 mg L-1 APAM], the maximum percent removal of Cd(II) was observed to reach 93.65%. A potential flocculation mechanism for the Cd(II) removal from water was further studied by evaluating the colloid Zeta potential. Results from these studies demonstrated that PAC had a greater capability to change the Zeta potential of collide under alkaline conditions, while APAM played a critical role in the bridging, enmeshment, and sweeping effect. The composite of two types of predominance makes considerable sense in regards to enhancing flocculating efficiency, decreasing secondary pollution, and reducing flocculant cost.

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