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International Journal of Molecular... Jun 2024Water deficit is the major stress factor magnified by climate change that causes the most reductions in plant productivity. Knowledge of photosystem II (PSII) response...
Water deficit is the major stress factor magnified by climate change that causes the most reductions in plant productivity. Knowledge of photosystem II (PSII) response mechanisms underlying crop vulnerability to drought is critical to better understanding the consequences of climate change on crop plants. Salicylic acid (SA) application under drought stress may stimulate PSII function, although the exact mechanism remains essentially unclear. To reveal the PSII response mechanism of celery plants sprayed with water (WA) or SA, we employed chlorophyll fluorescence imaging analysis at 48 h, 96 h, and 192 h after watering. The results showed that up to 96 h after watering, the stroma lamellae of SA-sprayed leaves appeared dilated, and the efficiency of PSII declined, compared to WA-sprayed plants, which displayed a better PSII function. However, 192 h after watering, the stroma lamellae of SA-sprayed leaves was restored, while SA boosted chlorophyll synthesis, and by ameliorating the osmotic potential of celery plants, it resulted in higher relative leaf water content compared to WA-sprayed plants. SA, by acting as an antioxidant under drought stress, suppressed phototoxicity, thereby offering PSII photoprotection, together with enhanced effective quantum yield of PSII photochemistry (Φ) and decreased quantity of singlet oxygen (O) generation compared to WA-sprayed plants. The PSII photoprotection mechanism induced by SA under drought stress was triggered by non-photochemical quenching (NPQ), which is a strategy to protect the chloroplast from photo-oxidative damage by dissipating the excess light energy as heat. This photoprotective mechanism, triggered by NPQ under drought stress, was adequate in keeping, especially in high-light conditions, an equal fraction of open PSII reaction centers (q) as of non-stress conditions. Thus, under water deficit stress, SA activates a regulatory network of stress and light energy partitioning signaling that can mitigate, to an extent, the water deficit stress on PSII functioning.
Topics: Photosystem II Protein Complex; Salicylic Acid; Plant Leaves; Chlorophyll; Apium; Droughts; Water; Photosynthesis; Dehydration; Stress, Physiological
PubMed: 38928427
DOI: 10.3390/ijms25126721 -
International Journal of Molecular... Jun 2024Bosentan, an endothelin receptor antagonist (ERA), has potential anti-atherosclerotic properties. We investigated the complementary effects of bosentan and atorvastatin...
Bosentan, an endothelin receptor antagonist (ERA), has potential anti-atherosclerotic properties. We investigated the complementary effects of bosentan and atorvastatin on the progression and composition of the atherosclerotic lesions in diabetic mice. Forty-eight male mice were fed high-fat diet (HFD) for 14 weeks. At week 8, diabetes was induced with streptozotocin, and mice were randomized into four groups: (1) control/COG: no intervention; (2) ΒOG: bosentan 100 mg/kg/day per os; (3) ATG: atorvastatin 20 mg/kg/day per os; and (4) BO + ATG: combined administration of bosentan and atorvastatin. The intra-plaque contents of collagen, elastin, monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-a (TNF-a), matrix metalloproteinases (MMP-2, -3, -9), and TIMP-1 were determined. The percentage of lumen stenosis was significantly lower across all treated groups: BOG: 19.5 ± 2.2%, ATG: 12.8 ± 4.8%, and BO + ATG: 9.1 ± 2.7% compared to controls (24.6 ± 4.8%, < 0.001). The administration of both atorvastatin and bosentan resulted in significantly higher collagen content and thicker fibrous cap versus COG ( < 0.01). All intervention groups showed lower relative intra-plaque concentrations of MCP-1, MMP-3, and MMP-9 and a higher TIMP-1concentration compared to COG ( < 0.001). Importantly, latter parameters presented lower levels when bosentan was combined with atorvastatin compared to COG ( < 0.05). Bosentan treatment in diabetic, atherosclerotic mice delayed the atherosclerosis progression and enhanced plaques' stability, showing modest but additive effects with atorvastatin, which are promising in atherosclerotic cardiovascular diseases.
Topics: Animals; Bosentan; Atorvastatin; Mice; Male; Atherosclerosis; Endothelin Receptor Antagonists; Diabetes Mellitus, Experimental; Drug Therapy, Combination; Collagen; Diet, High-Fat; Chemokine CCL2; Tumor Necrosis Factor-alpha; Plaque, Atherosclerotic; Mice, Knockout; Tissue Inhibitor of Metalloproteinase-1
PubMed: 38928320
DOI: 10.3390/ijms25126614 -
International Journal of Molecular... Jun 2024Water deficit affects the growth as well as physiological and biochemical processes in plants. The aim of this study was to determine differences in physiological and...
Water deficit affects the growth as well as physiological and biochemical processes in plants. The aim of this study was to determine differences in physiological and biochemical responses to drought stress in two wheat cultivars-Chinese Spring (CS) and SQ1 (which are parents of a mapping population of doubled haploid lines)-and to relate these responses to final yield and agronomic traits. Drought stress was induced by withholding water for 14 days, after which plants were re-watered and maintained until harvest. Instantaneous gas exchange parameters were evaluated on the 3rd, 5th, 10th, and 14th days of seedling growth under drought. After 14 days, water content and levels of chlorophyll +, carotenoids, malondialdehyde, soluble carbohydrates, phenolics, salicylic acid, abscisic acid (ABA), and polyamines were measured. At final maturity, yield components (grain number and weight), biomass, straw weight, and harvest index were evaluated. Physiological and biochemical parameters of CS responded more than those of SQ1 to the 14-day drought, reflected in a greater reduction in final biomass and yield in CS. Marked biochemical differences between responses of CS and SQ1 to the drought were found for soluble carbohydrates and polyamines. These would be good candidates for testing in the mapping population for the coincidence of the genetic control of these traits and final biomass and yield.
Topics: Triticum; Droughts; Stress, Physiological; Chlorophyll; Water; Chromosome Mapping; Biomass; Abscisic Acid; Seedlings
PubMed: 38928284
DOI: 10.3390/ijms25126573 -
International Journal of Molecular... Jun 2024MIXTA-like transcription factors AtMYB16 and AtMYB106 play important roles in the regulation of cuticular wax accumulation in dicot model plant , but there are very few...
MIXTA-like transcription factors AtMYB16 and AtMYB106 play important roles in the regulation of cuticular wax accumulation in dicot model plant , but there are very few studies on the MIXTA-like transcription factors in monocot plants. Herein, wheat MIXTA-like transcription factors TaMIXTA1 and TaMIXTA2 were characterized as positive regulators of cuticular wax accumulation. The virus-induced gene silencing experiments showed that knock-down of wheat and expressions resulted in the decreased accumulation of leaf cuticular wax, increased leaf water loss rate, and potentiated chlorophyll leaching. Furthermore, three wheat orthologous genes of (, , and ) and their function in cuticular wax deposition were reported. The silencing of by BSMV-VIGS led to reduced loads of leaf cuticular wax and enhanced rates of leaf water loss and chlorophyll leaching, indicating the essential role of the gene in the deposition of wheat cuticular wax. In addition, we demonstrated that TaMIXTA1 and TaMIXTA2 function as transcriptional activators and could directly stimulate the transcription of wax biosynthesis gene and wax deposition gene . The above results strongly support that wheat MIXTA-Like transcriptional activators TaMIXTA1 and TaMIXTA2 positively regulate cuticular wax accumulation via activating and gene transcription.
Topics: Waxes; Triticum; Gene Expression Regulation, Plant; Plant Proteins; Transcription Factors; Plant Leaves; Chlorophyll; Trans-Activators; Plant Epidermis
PubMed: 38928263
DOI: 10.3390/ijms25126557 -
International Journal of Molecular... Jun 2024Photodynamic Therapy (PDT) is recognized for its exceptional effectiveness as a promising cancer treatment method. However, it is noted that overexposure to the dosage...
Photodynamic Therapy (PDT) is recognized for its exceptional effectiveness as a promising cancer treatment method. However, it is noted that overexposure to the dosage and sunlight in traditional PDT can result in damage to healthy tissues, due to the low tumor selectivity of currently available photosensitizers (PSs). To address this challenge, we introduce herein a new strategy where the small molecule-targeted agent, erlotinib, is integrated into a boron dipyrromethene (BODIPY)-based PS to form conjugate to enhance the precision of PDT. This conjugate demonstrates optical absorption, fluorescence emission, and singlet oxygen generation efficiency comparable to the reference compound , which lacks erlotinib. In vitro studies reveal that, after internalization, conjugate predominantly accumulates in the lysosomes of HepG2 cells, exhibiting significant photocytotoxicity with an IC value of 3.01 µM. A distinct preference for HepG2 cells over HELF cells is observed with conjugate but not with compound . In vivo experiments further confirm that conjugate has a specific affinity for tumor tissues, and the combination treatment of conjugate with laser illumination can effectively eradicate H22 tumors in mice with outstanding biosafety. This study presents a novel and potential PS for achieving precise PDT against cancer.
Topics: Humans; Photochemotherapy; Animals; Mice; Porphobilinogen; Photosensitizing Agents; Hep G2 Cells; Liver Neoplasms; Erlotinib Hydrochloride; Boron Compounds
PubMed: 38928126
DOI: 10.3390/ijms25126421 -
International Journal of Molecular... Jun 2024Ferrochelatase (FECH) is the terminal enzyme in human heme biosynthesis, catalyzing the insertion of ferrous iron into protoporphyrin IX (PPIX) to form protoheme IX...
Ferrochelatase (FECH) is the terminal enzyme in human heme biosynthesis, catalyzing the insertion of ferrous iron into protoporphyrin IX (PPIX) to form protoheme IX (Heme). Phosphorylation increases the activity of FECH, and it has been confirmed that the activity of FECH phosphorylated at T116 increases. However, it remains unclear whether the T116 site and other potential phosphorylation modification sites collaboratively regulate the activity of FECH. In this study, we identified a new phosphorylation site, T218, and explored the allosteric effects of unphosphorylated (UP), PT116, PT218, and PT116 + PT218 states on FECH in the presence and absence of substrates (PPIX and Heme) using molecular dynamics (MD) simulations. Binding free energies were evaluated with the MM/PBSA method. Our findings indicate that the PT116 + PT218 state exhibits the lowest binding free energy with PPIX, suggesting the strongest binding affinity. Additionally, this state showed a higher binding free energy with Heme compared to UP, which facilitates Heme release. Moreover, employing multiple analysis methods, including free energy landscape (FEL), principal component analysis (PCA), dynamic cross-correlation matrix (DCCM), and hydrogen bond interaction analysis, we demonstrated that phosphorylation significantly affects the dynamic behavior and binding patterns of substrates to FECH. Insights from this study provide valuable theoretical guidance for treating conditions related to disrupted heme metabolism, such as various porphyrias and iron-related disorders.
Topics: Ferrochelatase; Humans; Phosphorylation; Molecular Dynamics Simulation; Heme; Protoporphyrins; Catalytic Domain; Protein Binding; Binding Sites; Thermodynamics
PubMed: 38928065
DOI: 10.3390/ijms25126360 -
International Journal of Molecular... Jun 2024The development of resistance to tyrosine kinase inhibitors (TKIs) is a major cause of treatment failure in metastatic renal cell carcinoma (mRCC). A deeper...
The development of resistance to tyrosine kinase inhibitors (TKIs) is a major cause of treatment failure in metastatic renal cell carcinoma (mRCC). A deeper understanding of the metabolic mechanisms associated with TKI resistance is critical for refining therapeutic strategies. In this study, we established resistance to sunitinib and pazopanib by exposing a parental Caki-1 cell line to increasing concentrations of sunitinib and pazopanib. The intracellular and extracellular metabolome of sunitinib- and pazopanib-resistant mRCC cells were investigated using a nuclear magnetic resonance (NMR)-based metabolomics approach. Data analysis included multivariate and univariate methods, as well as pathway and network analyses. Distinct metabolic signatures in sunitinib- and pazopanib-resistant RCC cells were found for the first time in this study. A common metabolic reprogramming pattern was observed in amino acid, glycerophospholipid, and nicotinate and nicotinamide metabolism. Sunitinib-resistant cells exhibited marked alterations in metabolites involved in antioxidant defence mechanisms, while pazopanib-resistant cells showed alterations in metabolites associated with energy pathways. Sunitinib-resistant RCC cells demonstrated an increased ability to proliferate, whereas pazopanib-resistant cells appeared to restructure their energy metabolism and undergo alterations in pathways associated with cell death. These findings provide potential targets for novel therapeutic strategies to overcome TKI resistance in mRCC through metabolic regulation.
Topics: Humans; Drug Resistance, Neoplasm; Kidney Neoplasms; Protein Kinase Inhibitors; Cell Line, Tumor; Sunitinib; Sulfonamides; Metabolomics; Indazoles; Carcinoma, Renal Cell; Pyrimidines; Metabolome; Cell Proliferation; Tyrosine Kinase Inhibitors
PubMed: 38928035
DOI: 10.3390/ijms25126328 -
Genes Jun 2024Chilling stress is one of the main abiotic factors affecting rice growth and yield. In rice, chlorophyllide oxygenase encoded by is responsible for converting...
Chilling stress is one of the main abiotic factors affecting rice growth and yield. In rice, chlorophyllide oxygenase encoded by is responsible for converting chlorophyllide to chlorophyllide , playing a crucial role in photosynthesis and thus rice growth. However, little is known about the function of in chilling stress responses. The presence of the -acting element involved in low-temperature responsiveness (LTR) in the promoter implied that probably is a cold-responsive gene. The gene expression level of was usually inhibited by low temperatures during the day and promoted by low temperatures at night. The knockout mutants generated by the CRISPR-Cas9 technology in rice ( L.) exhibited significantly weakened chilling tolerance at the seedling stage. dysfunction led to the accumulation of reactive oxygen species and malondialdehyde, an increase in relative electrolyte leakage, and a reduction in antioxidant gene expression under chilling stress. In addition, the functional deficiency of resulted in more severe damage to chloroplast morphology, such as abnormal grana thylakoid stacking, caused by low temperatures. Moreover, the rice yield was reduced in knockout mutants. Therefore, the elevated expression of probably has the potential to increase both rice yield and chilling tolerance simultaneously, providing a strategy to cultivate chilling-tolerant rice varieties with high yields.
Topics: Oryza; Seedlings; Cold Temperature; Gene Expression Regulation, Plant; Plant Proteins; Oxygenases; Cold-Shock Response; Gene Knockout Techniques; Reactive Oxygen Species; Chlorophyll; Photosynthesis
PubMed: 38927664
DOI: 10.3390/genes15060721 -
Genes May 2024LONP1 is the principal AAA+ unfoldase and bulk protease in the mitochondrial matrix, so its deletion causes embryonic lethality. The AAA+ unfoldase CLPX and the... (Review)
Review
Knockout Mouse Studies Show That Mitochondrial CLPP Peptidase and CLPX Unfoldase Act in Matrix Condensates near IMM, as Fast Stress Response in Protein Assemblies for Transcript Processing, Translation, and Heme Production.
LONP1 is the principal AAA+ unfoldase and bulk protease in the mitochondrial matrix, so its deletion causes embryonic lethality. The AAA+ unfoldase CLPX and the peptidase CLPP also act in the matrix, especially during stress periods, but their substrates are poorly defined. Mammalian CLPP deletion triggers infertility, deafness, growth retardation, and cGAS-STING-activated cytosolic innate immunity. CLPX mutations impair heme biosynthesis and heavy metal homeostasis. CLPP and CLPX are conserved from bacteria to humans, despite their secondary role in proteolysis. Based on recent proteomic-metabolomic evidence from knockout mice and patient cells, we propose that CLPP acts on phase-separated ribonucleoprotein granules and CLPX on multi-enzyme condensates as first-aid systems near the inner mitochondrial membrane. Trimming within assemblies, CLPP rescues stalled processes in mitoribosomes, mitochondrial RNA granules and nucleoids, and the D-foci-mediated degradation of toxic double-stranded mtRNA/mtDNA. Unfolding multi-enzyme condensates, CLPX maximizes PLP-dependent delta-transamination and rescues malformed nascent peptides. Overall, their actions occur in granules with multivalent or hydrophobic interactions, separated from the aqueous phase. Thus, the role of CLPXP in the matrix is compartment-selective, as other mitochondrial peptidases: MPPs at precursor import pores, m-AAA and i-AAA at either IMM face, PARL within the IMM, and OMA1/HTRA2 in the intermembrane space.
Topics: Endopeptidase Clp; Animals; Mice; Mitochondria; Mitochondrial Proteins; Mice, Knockout; Heme; Protein Biosynthesis; Humans; Mitochondrial Membranes; Stress, Physiological
PubMed: 38927630
DOI: 10.3390/genes15060694 -
Biomolecules Jun 2024Lysine acetylation of proteins plays a critical regulatory function in plants. A few advances have been made in the study of plant acetylproteome. However, until now,...
Lysine acetylation of proteins plays a critical regulatory function in plants. A few advances have been made in the study of plant acetylproteome. However, until now, there have been few data on Pall. (). We analyzed the molecular mechanisms of photosynthesis and stress resistance in under UV-B stress. We measured chlorophyll fluorescence parameters of under UV-B stress and performed a multi-omics analysis. Based on the determination of chlorophyll fluorescence parameters, Y(NO) (Quantum yield of non-photochemical quenching) increased under UV-B stress, indicating that the plant was damaged and photosynthesis decreased. In the analysis of acetylated proteomics data, acetylated proteins were found to be involved in a variety of biological processes. Notably, acetylated proteins were significantly enriched in the pathways of photosynthesis and carbon fixation, suggesting that lysine acetylation modifications have an important role in these activities. Our findings suggest that has decreased photosynthesis and impaired photosystems under UV-B stress, but NPQ shows that plants are resistant to UV-B. Acetylation proteomics revealed that up- or down-regulation of acetylation modification levels alters protein expression. Acetylation modification of key enzymes of the Calvin cycle (Rubisco, GAPDH) regulates protein expression, making Rubisco and GAPDH proteins expressed as significantly different proteins, which in turn affects the carbon fixation capacity of . Thus, Rubisco and GAPDH are significantly differentially expressed after acetylation modification, which affects the carbon fixation capacity and thus makes the plant resistant to UV-B stress. Lysine acetylation modification affects biological processes by regulating the expression of key enzymes in photosynthesis and carbon fixation, making plants resistant to UV-B stress.
Topics: Acetylation; Ultraviolet Rays; Photosynthesis; Carbon Cycle; Rhododendron; Ribulose-Bisphosphate Carboxylase; Stress, Physiological; Plant Proteins; Proteomics; Gene Expression Regulation, Plant; Chlorophyll; Lysine
PubMed: 38927135
DOI: 10.3390/biom14060732