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1.
Nan Fang Yi Ke Da Xue Xue Bao ; 44(4): 636-643, 2024 Apr 20.
Article in Chinese | MEDLINE | ID: mdl-38708495

ABSTRACT

OBJECTIVE: To investigate the effect of Jisuikang formula-medicated serum for promoting spinal cord injury (SCI) repair in rats and explore the possible mechanism. METHODS: Thirty adult SD rats were randomized into sham-operated group, SCI (induced using a modified Allen method) model group, and Jisuikang formula-medicated serum treatment group. After the operations, the rats were treated with normal saline or Jisuikang by gavage on a daily basis for 14 days, and the changes in hindlimb motor function of the rats was assessed with Basso-Beattie-Bresnahan (BBB) scores and inclined-plate test. The injured spinal cord tissues were sampled from the SCI rat models for single-cell RNA sequencing, and bioinformatics analysis was performed to identify the target genes of Jisuikang, spinal cord injury and glycolysis. In the cell experiment, cultured astrocytes from neonatal SD rat cortex were treated with SOX2 alone or in combination with Jisuikang-medicated serum for 21 days, and the protein expressions of PKM2, p-PKM2 and YAP and colocalization of PKM2 and YAP in the cells were analyzed with Western blotting and immunofluorescence staining, respectively. RESULTS: The SCI rats with Jisuikang treatment showed significantly improved BBB scores and performance in inclined-plate test. At the injury site, high PKM2 expression was detected in various cell types. Bioinformatic analysis identified the HIPPO-YAP signaling pathway as the target pathway of Jisuikang. In cultured astrocytes, SOX2 combined with the mediated serum, as compared with SOX2 alone, significantly increased PKM2, p-PKM2 and YAP expressions and entry of phosphorylated PKM2 into the nucleus, and promoted PKM2 and YAP co-localization in the cells. CONCLUSION: Jisuikang formula accelerates SCI repair in rats possibly by promoting aerobic glycolysis of the astrocytes via activating the PKM2/YAP axis to induce reprogramming of the astrocytes into neurons.


Subject(s)
Astrocytes , Pyruvate Kinase , Signal Transduction , Spinal Cord Injuries , YAP-Signaling Proteins , Animals , Rats , Astrocytes/metabolism , Astrocytes/drug effects , Carrier Proteins/metabolism , Disease Models, Animal , Drugs, Chinese Herbal/pharmacology , Membrane Proteins/metabolism , Rats, Sprague-Dawley , Signal Transduction/drug effects , Spinal Cord Injuries/metabolism , Spinal Cord Injuries/drug therapy , Thyroid Hormone-Binding Proteins , Thyroid Hormones/metabolism
2.
Sci Adv ; 10(22): eadl0320, 2024 May 31.
Article in English | MEDLINE | ID: mdl-38820160

ABSTRACT

Translation of mRNAs is a fundamental process that occurs in all cell types of multicellular organisms. Conventionally, it has been considered a default step in gene expression, lacking specific regulation. However, recent studies have documented that certain mRNAs exhibit cell type-specific translation. Despite this, it remains unclear whether global translation is controlled in a cell type-specific manner. By using human cell lines and mouse models, we found that deletion of the ribosome-associated protein ribonuclease inhibitor 1 (RNH1) decreases global translation selectively in hematopoietic-origin cells but not in the non-hematopoietic-origin cells. RNH1-mediated cell type-specific translation is mechanistically linked to angiogenin-induced ribosomal biogenesis. Collectively, this study unravels the existence of cell type-specific global translation regulators and highlights the complex translation regulation in vertebrates.


Subject(s)
Protein Biosynthesis , Ribonuclease, Pancreatic , Ribosomes , Ribonuclease, Pancreatic/metabolism , Ribonuclease, Pancreatic/genetics , Humans , Animals , Mice , Ribosomes/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Gene Expression Regulation , Cell Line , Organ Specificity , Carrier Proteins
3.
Life Sci ; 349: 122719, 2024 Jul 15.
Article in English | MEDLINE | ID: mdl-38759866

ABSTRACT

In the vast landscape of human health, head and neck cancer (HNC) poses a significant health burden globally, necessitating the exploration of novel diagnostics and therapeutics. Metabolic alterations occurring within tumor microenvironment are crucial to understand the foundational cause of HNC. Post-translational modifications (PTMs) have recently emerged as a silent foe exerting a significantly heightened influence on various aspects of the biological processes associated with the onset and advancement of cancer, particularly in the context of HNC. There are numerous targets involved in HNC but recently, the enzyme pyruvate kinase M2 (PKM2) has come out as a hot target due to its involvement in glycolysis resulting in metabolic reprogramming of cancer cells. Various PTMs have been reported to affect the structure and function of PKM2 by modulating its activity. This review aims to investigate the impact of PTMs on the interaction between PKM2 and several signaling pathways and transcription factors in the context of HNC. These interactions possess significant ramification for cellular proliferation, apoptosis, angiogenesis and metastasis. This review primarily explores the role of PTMs influencing PKM2 and its involvement in tumor development. While acknowledging the significance of PKM2 interactions with other tumor regulators, the emphasis lies on dissecting PTM-related mechanisms rather than solely scrutinizing individual regulators. It lays the framework for the development of more sophisticated diagnostic tools and uncovers exciting possibilities for precision medicine essential for effectively addressing the complexity of this malignancy in a precise and focused manner.


Subject(s)
Carrier Proteins , Head and Neck Neoplasms , Membrane Proteins , Protein Processing, Post-Translational , Thyroid Hormone-Binding Proteins , Thyroid Hormones , Humans , Head and Neck Neoplasms/metabolism , Head and Neck Neoplasms/pathology , Thyroid Hormones/metabolism , Membrane Proteins/metabolism , Carrier Proteins/metabolism , Tumor Microenvironment , Animals , Signal Transduction
4.
J Genet ; 1032024.
Article in English | MEDLINE | ID: mdl-38736250

ABSTRACT

In acute lymphoblastic leukaemia (ALL), elevated foetal haemoglobin (HbF) levels have been associated with the prognosis of patients. Genetic variants in HbF regulatory genes: BAF chromatin remodelling complex subunit (BCL11A), HBS1L-MYB transcriptional GTPase intergenic region (HBS1L-MYB), Krüppel-like factor 1 (KLF1), haemoglobin gamma subunit 2 (HBG2), haemoglobin gamma subunit 1 (HBG1), and haemoglobin subunit beta pseudogene 1 (HBBP1) are often associatedwith elevatedHbF concentration. This study investigated the association of genetic variants in HbF regulatory genes with HbF concentration, unfavourable prognosis, and outcome in children with ALL.We quantified HbF concentration and genotyped 17 genetic variants in 48 patients with ALL and 64 children without ALL as a reference group. HbF concentrationwas higher in patients than in the reference group (4.4%vs 1.4%), and 75%(n = 36) of thepatientshadHbF>2.5%.Unfavourable prognosis ALL was established in 68.8% (n = 33) of the patients. Variant HBG2 rs7482144 was associated with high HbF concentration (P = 0.015); while HBS1L-MYB rs9399137 (P = 0.001), HBG2 rs7482144 (P = 0.001) and the ß-globin genes HBG2, HBG1, and HBPP1 haplotypeTGC(P = 0.017) with unfavourable prognosisALL.Additionally, variantBCL11A rs4671393 showed a protective role (P = 0.0001). In conclusion, variants HBG2 rs7482144, HBS1L-MYB rs9399137 and BCL11A rs4671393 may play a significant role in ALL.


Subject(s)
Fetal Hemoglobin , Polymorphism, Single Nucleotide , Precursor Cell Lymphoblastic Leukemia-Lymphoma , Repressor Proteins , Humans , Fetal Hemoglobin/genetics , Female , Male , Child , Prognosis , Repressor Proteins/genetics , Child, Preschool , Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics , Infant , Nuclear Proteins/genetics , Proto-Oncogene Proteins c-myb/genetics , Carrier Proteins/genetics , Adolescent , Genotype , gamma-Globins/genetics , GTP-Binding Proteins
5.
Zhonghua Gan Zang Bing Za Zhi ; 32(4): 354-362, 2024 Apr 20.
Article in Chinese | MEDLINE | ID: mdl-38733191

ABSTRACT

Objective: To observe the therapeutic effect of Shengsan Jiedu Huayu decoction in alleviating inflammatory liver injury in rats with acute-on-chronic liver failure (ACLF) and its effect on the activation intensity for the NLRP3 signaling pathway. Methods: 63 SD rats were randomly divided into a blank group, a model group, and low-, medium-, and high-dose groups of Shengsan Jiedu Huayu decoction (7.29 g/kg/d, 14.58 g/kg/d, and 29.16 g/kg/d). The ACLF rat model was replicated using carbon tetrachloride combined with d-galactosamine and lipopolysaccharide. Different dose gradients of the Shengsan Jiedu Huayu decoction were used for a five-day intervention treatment, and then rat serum and tissue samples were collected. A biochemical analyzer was used to detect the serum levels of ALT, AST, and TBIL in rats. ELISA was used to detect serum IL-18 and IL-1ß content. HE staining was used to observe histomorphological changes in liver tissue. Immunohistochemistry was used to detect GSDMD expression in liver tissue. Western blot and PCR were used to detect NLRP3, Caspase1, ASC, TLR4, IL-1ß, IL-18 protein, and mRNA expression levels.The groups were compared using analysis of variance and the rank-sum test. Results: Compared with the blank group, the model group's rat liver tissue was severely injured. Serum levels of ALT, AST, and TBIL, inflammatory factors IL-1ß and IL-18, and the GSDMD protein expression level, NLRP3 expression level, TLR4, caspase 1, ASC, IL-1ß, IL-18 protein, and mRNA (P<0.01) were all significantly increased in the model than the blank group (P<0.01). Additionally, compared with the model group, the low-, medium-, and high-dose groups of Shengsan Jiedu Huayu decoction had improved liver tissue injury in ACLF rats, while the serum levels of ALT, AST, TBIL, IL-1ß, IL-18, liver tissue GSDMD protein, NLRP3, TLR4, caspase 1, and ASC expressions were all lower in the different dose gradients of the Shengsan Jiedu Huayu decoction than the model group, with the most evident reduction in the high-dose group (P<0.01). Conclusion: Shengsan Jiedu Huayu decoction can weaken the activation intensity of the NLRP3 signaling pathway, alleviate liver tissue pathological injury, reduce inflammatory factor release, and alleviate inflammatory liver injury in ACLF rats.


Subject(s)
Acute-On-Chronic Liver Failure , Drugs, Chinese Herbal , NLR Family, Pyrin Domain-Containing 3 Protein , Rats, Sprague-Dawley , Signal Transduction , Animals , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Acute-On-Chronic Liver Failure/drug therapy , Acute-On-Chronic Liver Failure/etiology , Drugs, Chinese Herbal/pharmacology , Rats , Signal Transduction/drug effects , Male , Interleukin-18/metabolism , Liver/metabolism , Liver/drug effects , Liver/pathology , Interleukin-1beta/metabolism , Toll-Like Receptor 4/metabolism , Carrier Proteins/metabolism
6.
Biochem Biophys Res Commun ; 716: 149954, 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38704887

ABSTRACT

Membrane lipids and proteins form dynamic domains crucial for physiological and pathophysiological processes, including viral infection. Many plasma membrane proteins, residing within membrane domains enriched with cholesterol (CHOL) and sphingomyelin (SM), serve as receptors for attachment and entry of viruses into the host cell. Among these, human coronaviruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), use proteins associated with membrane domains for initial binding and internalization. We hypothesized that the interaction of lipid-binding proteins with CHOL in plasma membrane could sequestrate lipids and thus affect the efficiency of virus entry into host cells, preventing the initial steps of viral infection. We have prepared CHOL-binding proteins with high affinities for lipids in the plasma membrane of mammalian cells. Binding of the perfringolysin O domain four (D4) and its variant D4E458L to membrane CHOL impaired the internalization of the receptor-binding domain of the SARS-CoV-2 spike protein and the pseudovirus complemented with the SARS-CoV-2 spike protein. SARS-CoV-2 replication in Vero E6 cells was also decreased. Overall, our results demonstrate that the integrity of CHOL-rich membrane domains and the accessibility of CHOL in the membrane play an essential role in SARS-CoV-2 cell entry.


Subject(s)
Cell Membrane , Cholesterol , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Virus Internalization , Vero Cells , Chlorocebus aethiops , Cholesterol/metabolism , Animals , SARS-CoV-2/metabolism , SARS-CoV-2/physiology , Cell Membrane/metabolism , Cell Membrane/virology , Spike Glycoprotein, Coronavirus/metabolism , Spike Glycoprotein, Coronavirus/chemistry , Humans , Carrier Proteins/metabolism , COVID-19/virology , COVID-19/metabolism , Protein Binding
7.
Nat Commun ; 15(1): 4015, 2024 May 13.
Article in English | MEDLINE | ID: mdl-38740766

ABSTRACT

Microfibril-associated glycoprotein 4 (MFAP4) is a 36-kDa extracellular matrix glycoprotein with critical roles in organ fibrosis, chronic obstructive pulmonary disease, and cardiovascular disorders, including aortic aneurysms. MFAP4 multimerises and interacts with elastogenic proteins, including fibrillin-1 and tropoelastin, and with cells via integrins. Structural details of MFAP4 and its potential interfaces for these interactions are unknown. Here, we present a cryo-electron microscopy structure of human MFAP4. In the presence of calcium, MFAP4 assembles as an octamer, where two sets of homodimers constitute the top and bottom halves of each octamer. Each homodimer is linked together by an intermolecular disulphide bond. A C34S missense mutation prevents disulphide-bond formation between monomers but does not prevent octamer assembly. The atomic model, built into the 3.55 Å cryo-EM map, suggests that salt-bridge interactions mediate homodimer assembly, while non-polar residues form the interface between octamer halves. In the absence of calcium, an MFAP4 octamer dissociates into two tetramers. Binding studies with fibrillin-1, tropoelastin, LTBP4, and small fibulins show that MFAP4 has multiple surfaces for protein-protein interactions, most of which depend upon MFAP4 octamer assembly. The C34S mutation does not affect these protein interactions or cell interactions. MFAP4 assemblies with fibrillin-1 abrogate MFAP4 interactions with cells.


Subject(s)
Cryoelectron Microscopy , Extracellular Matrix Proteins , Fibrillin-1 , Tropoelastin , Humans , Fibrillin-1/metabolism , Fibrillin-1/genetics , Fibrillin-1/chemistry , Tropoelastin/metabolism , Tropoelastin/chemistry , Tropoelastin/genetics , Extracellular Matrix Proteins/metabolism , Extracellular Matrix Proteins/chemistry , Extracellular Matrix Proteins/genetics , Protein Multimerization , Protein Binding , Models, Molecular , Calcium/metabolism , Mutation, Missense , Microfibrils/metabolism , Microfibrils/chemistry , Microfibrils/ultrastructure , HEK293 Cells , Carrier Proteins , Glycoproteins , Adipokines
8.
Metallomics ; 16(5)2024 May 02.
Article in English | MEDLINE | ID: mdl-38692844

ABSTRACT

Eukaryotic DNA codes not only for proteins but contains a wealth of information required for accurate splicing of messenger RNA precursors and inclusion of constitutively or alternatively spliced exons in mature transcripts. This "auxiliary" splicing code has been characterized as exonic splicing enhancers and silencers (ESE and ESS). The exact interplay between protein and splicing codes is, however, poorly understood. Here, we show that exons encoding copper-coordinating amino acids in human cuproproteins lack ESEs and/or have an excess of ESSs, yet RNA sequencing and expressed sequence tags data show that they are more efficiently included in mature transcripts by the splicing machinery than average exons. Their largely constitutive inclusion in messenger RNA is facilitated by stronger splice sites, including polypyrimidine tracts, consistent with an important role of the surrounding intron architecture in ensuring high expression of metal-binding residues during evolution. ESE/ESS profiles of codons and entire exons that code for copper-coordinating residues were very similar to those encoding residues that coordinate zinc but markedly different from those that coordinate calcium. Together, these results reveal how the traditional and auxiliary splicing motifs responded to constraints of metal coordination in proteins.


Subject(s)
Copper , Exons , RNA Splicing , Humans , Exons/genetics , Copper/metabolism , Alternative Splicing , RNA, Messenger/genetics , RNA, Messenger/metabolism , Enhancer Elements, Genetic/genetics , Carrier Proteins/genetics , Carrier Proteins/metabolism
9.
Elife ; 122024 May 10.
Article in English | MEDLINE | ID: mdl-38727583

ABSTRACT

Retinitis pigmentosa (RP) is an inherited retinal disease in which there is a loss of cone-mediated daylight vision. As there are >100 disease genes, our goal is to preserve cone vision in a disease gene-agnostic manner. Previously we showed that overexpressing TXNIP, an α-arrestin protein, prolonged cone vision in RP mouse models, using an AAV to express it only in cones. Here, we expressed different alleles of Txnip in the retinal pigmented epithelium (RPE), a support layer for cones. Our goal was to learn more of TXNIP's structure-function relationships for cone survival, as well as determine the optimal cell type expression pattern for cone survival. The C-terminal half of TXNIP was found to be sufficient to remove GLUT1 from the cell surface, and improved RP cone survival, when expressed in the RPE, but not in cones. Knock-down of HSP90AB1, a TXNIP-interactor which regulates metabolism, improved the survival of cones alone and was additive for cone survival when combined with TXNIP. From these and other results, it is likely that TXNIP interacts with several proteins in the RPE to indirectly support cone survival, with some of these interactions different from those that lead to cone survival when expressed only in cones.


Subject(s)
Carrier Proteins , Disease Models, Animal , Retinal Cone Photoreceptor Cells , Retinitis Pigmentosa , Animals , Retinitis Pigmentosa/genetics , Retinitis Pigmentosa/metabolism , Retinal Cone Photoreceptor Cells/metabolism , Retinal Cone Photoreceptor Cells/pathology , Mice , Carrier Proteins/genetics , Carrier Proteins/metabolism , Mutation, Missense , Cell Survival , Alleles , Gene Deletion , Thioredoxins/genetics , Thioredoxins/metabolism , Retinal Pigment Epithelium/metabolism
10.
Sci Signal ; 17(835): eadj0032, 2024 May 07.
Article in English | MEDLINE | ID: mdl-38713765

ABSTRACT

Serum response factor (SRF) is an essential transcription factor for brain development and function. Here, we explored how an SRF cofactor, the actin monomer-sensing myocardin-related transcription factor MRTF, is regulated in mouse cortical neurons. We found that MRTF-dependent SRF activity in vitro and in vivo was repressed by cyclase-associated protein CAP1. Inactivation of the actin-binding protein CAP1 reduced the amount of actin monomers in the cytoplasm, which promoted nuclear MRTF translocation and MRTF-SRF activation. This function was independent of cofilin1 and actin-depolymerizing factor, and CAP1 loss of function in cortical neurons was not compensated by endogenous CAP2. Transcriptomic and proteomic analyses of cerebral cortex lysates from wild-type and Cap1 knockout mice supported the role of CAP1 in repressing MRTF-SRF-dependent signaling in vivo. Bioinformatic analysis identified likely MRTF-SRF target genes, which aligned with the transcriptomic and proteomic results. Together with our previous studies that implicated CAP1 in axonal growth cone function as well as the morphology and plasticity of excitatory synapses, our findings establish CAP1 as a crucial actin regulator in the brain relevant for formation of neuronal networks.


Subject(s)
Actins , Carrier Proteins , Cerebral Cortex , Mice, Knockout , Serum Response Factor , Trans-Activators , Animals , Cerebral Cortex/metabolism , Trans-Activators/metabolism , Trans-Activators/genetics , Serum Response Factor/metabolism , Serum Response Factor/genetics , Mice , Actins/metabolism , Actins/genetics , Neurons/metabolism , Microfilament Proteins/metabolism , Microfilament Proteins/genetics , Gene Expression Regulation , Signal Transduction
11.
Physiol Rep ; 12(9): e15977, 2024 May.
Article in English | MEDLINE | ID: mdl-38697929

ABSTRACT

FAM111A gene mutations cause Kenney-Caffey syndrome (KCS) and Osteocraniostenosis (OCS), conditions characterized by short stature, low serum ionized calcium (Ca2+), low parathyroid hormone (PTH), and bony abnormalities. The molecular mechanism mediating this phenotype is unknown. The c-terminal domain of FAM111A harbors all the known disease-causing variations and encodes a domain with high homology to serine proteases. However, whether this serine protease domain contributes to the maintenance of Ca2+ homeostasis is not known. We hypothesized the disruption of the serine protease domain of FAM111A would disrupt Ca2+ homeostasis. To test this hypothesis, we generated with CRISPR/Cas9, mice with a frameshift insertion (c.1450insA) or large deletion (c.1253-1464del) mutation in the Fam111a serine protease domain. Serum-ionized Ca2+ and PTH levels were not significantly different between wild type, heterozygous, or homozygous Fam111a mutant mice. Additionally, there were no significant differences in fecal or urine Ca2+ excretion, intestinal Ca2+ absorption or overall Ca2+ balance. Only female homozygous (c.1450insA), but not heterozygous mice displayed differences in bone microarchitecture and mineral density compared to wild-type animals. We conclude that frameshift mutations that disrupt the c-terminal serine protease domain do not induce a KCS or OCS phenotype in mice nor alter Ca2+ homeostasis.


Subject(s)
Calcium , Carrier Proteins , Homeostasis , Animals , Calcium/metabolism , Mice , Parathyroid Hormone/metabolism , Female , Male , Serine Proteases/metabolism , Serine Proteases/genetics , Mice, Inbred C57BL
12.
Science ; 384(6698): 920-928, 2024 May 24.
Article in English | MEDLINE | ID: mdl-38781377

ABSTRACT

Excitatory and inhibitory synapses do not overlap even when formed on one submicron-sized dendritic protrusion. How excitatory and inhibitory postsynaptic cytomatrices or densities (e/iPSDs) are segregated is not understood. Broadly, why membraneless organelles are naturally segregated in cellular subcompartments is unclear. Using biochemical reconstitutions in vitro and in cells, we demonstrate that ePSDs and iPSDs spontaneously segregate into distinct condensed molecular assemblies through phase separation. Tagging iPSD scaffold gephyrin with a PSD-95 intrabody (dissociation constant ~4 nM) leads to mistargeting of gephyrin to ePSD condensates. Unexpectedly, formation of iPSD condensates forces the intrabody-tagged gephyrin out of ePSD condensates. Thus, instead of diffusion-governed spontaneous mixing, demixing is a default process for biomolecules in condensates. Phase separation can generate biomolecular compartmentalization specificities that cannot occur in dilute solutions.


Subject(s)
Biomolecular Condensates , Carrier Proteins , Membrane Proteins , Membrane Proteins/metabolism , Membrane Proteins/chemistry , Animals , Biomolecular Condensates/chemistry , Biomolecular Condensates/metabolism , Carrier Proteins/metabolism , Carrier Proteins/chemistry , Humans , Post-Synaptic Density/metabolism , Disks Large Homolog 4 Protein/metabolism , HEK293 Cells , Synapses/physiology , Phase Separation
13.
Physiol Plant ; 176(3): e14359, 2024.
Article in English | MEDLINE | ID: mdl-38797943

ABSTRACT

Lipid transfer proteins (LTPs) play crucial roles in various biological processes in plants, such as pollen tube adhesion, phospholipid transfer, cuticle synthesis, and response to abiotic stress. While a few members of the non-specific LTPs (nsLTPs) have been identified, their structural characteristics remain largely unexplored. Given the observed improvement in the performance of Antarctic plants facing water deficit when associated with fungal endophytes, this study aimed to assess the role of these symbiotic organisms in the transcriptional modulation of putative nsLTPs. The study focused on identifying and characterizing two nsLTP in the Antarctic plant Colobanthus quitensis that exhibit responsiveness to drought stress. Furthermore, we investigated the influence of Antarctic endophytic fungi on the expression profiles of these nsLTPs, as these fungi have been known to enhance plant physiological and biochemical performance under water deficit conditions. Through 3D modeling, docking, and molecular dynamics simulations with different substrates, the conducted structural and ligand-protein interaction analyses showed that differentially expressed nsLTPs displayed the ability to interact with various ligands, with a higher affinity towards palmitoyl-CoA. Overall, our findings suggest a regulatory mechanism for the expression of these two nsLTPs in Colobanthus quitensis under drought stress, further modulated by the presence of endophytic fungi.


Subject(s)
Carrier Proteins , Droughts , Endophytes , Plant Proteins , Endophytes/physiology , Endophytes/metabolism , Antarctic Regions , Carrier Proteins/metabolism , Carrier Proteins/genetics , Plant Proteins/genetics , Plant Proteins/metabolism , Gene Expression Regulation, Plant , Fungi/physiology , Fungi/genetics , Stress, Physiological , Molecular Dynamics Simulation
14.
Nat Commun ; 15(1): 4430, 2024 May 24.
Article in English | MEDLINE | ID: mdl-38789420

ABSTRACT

Histone H2AX plays a key role in DNA damage signalling in the surrounding regions of DNA double-strand breaks (DSBs). In response to DNA damage, H2AX becomes phosphorylated on serine residue 139 (known as γH2AX), resulting in the recruitment of the DNA repair effectors 53BP1 and BRCA1. Here, by studying resistance to poly(ADP-ribose) polymerase (PARP) inhibitors in BRCA1/2-deficient mammary tumours, we identify a function for γH2AX in orchestrating drug-induced replication fork degradation. Mechanistically, γH2AX-driven replication fork degradation is elicited by suppressing CtIP-mediated fork protection. As a result, H2AX loss restores replication fork stability and increases chemoresistance in BRCA1/2-deficient tumour cells without restoring homology-directed DNA repair, as highlighted by the lack of DNA damage-induced RAD51 foci. Furthermore, in the attempt to discover acquired genetic vulnerabilities, we find that ATM but not ATR inhibition overcomes PARP inhibitor (PARPi) resistance in H2AX-deficient tumours by interfering with CtIP-mediated fork protection. In summary, our results demonstrate a role for H2AX in replication fork biology in BRCA-deficient tumours and establish a function of H2AX separable from its classical role in DNA damage signalling and DSB repair.


Subject(s)
BRCA1 Protein , BRCA2 Protein , DNA Replication , Drug Resistance, Neoplasm , Histones , Poly(ADP-ribose) Polymerase Inhibitors , Humans , BRCA1 Protein/metabolism , BRCA1 Protein/deficiency , BRCA1 Protein/genetics , Histones/metabolism , Poly(ADP-ribose) Polymerase Inhibitors/pharmacology , DNA Replication/drug effects , BRCA2 Protein/metabolism , BRCA2 Protein/genetics , BRCA2 Protein/deficiency , Cell Line, Tumor , Female , Drug Resistance, Neoplasm/genetics , Animals , Ataxia Telangiectasia Mutated Proteins/metabolism , Ataxia Telangiectasia Mutated Proteins/genetics , DNA Breaks, Double-Stranded , Breast Neoplasms/genetics , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Breast Neoplasms/drug therapy , Mice , Tumor Suppressor p53-Binding Protein 1/metabolism , Tumor Suppressor p53-Binding Protein 1/genetics , DNA Repair , Carrier Proteins/metabolism , Carrier Proteins/genetics , DNA Damage , Rad51 Recombinase/metabolism , Rad51 Recombinase/genetics
15.
Cell Biol Toxicol ; 40(1): 38, 2024 May 24.
Article in English | MEDLINE | ID: mdl-38789868

ABSTRACT

Ensartinib, an approved ALK inhibitor, is used as a first-line therapy for advanced ALK-positive non-small cell lung cancer in China. However, the hepatotoxicity of ensartinib seriously limits its clinical application and the regulatory mechanism is still elusive. Here, through transcriptome analysis we found that transcriptional activation of TXNIP was the main cause of ensartinib-induced liver dysfunction. A high TXNIP level and abnormal TXNIP translocation severely impaired hepatic function via mitochondrial dysfunction and hepatocyte apoptosis, and TXNIP deficiency attenuated hepatocyte apoptosis under ensartinib treatment. The increase in TXNIP induced by ensartinib is related to AKT inhibition and is mediated by MondoA. Through screening potential TXNIP inhibitors, we found that the natural polyphenolic flavonoid rutin, unlike most reported TXNIP inhibitors can inhibit TXNIP by binding to TXNIP and partially promoting its proteasomal degradation. Further studies showed rutin can attenuate the hepatotoxicity of ensartinib without antagonizing its antitumor effects. Accordingly, we suggest that TXNIP is the key cause of ensartinib-induced hepatotoxicity and rutin is a potential clinically safe and feasible therapeutic strategy for TXNIP intervention.


Subject(s)
Apoptosis , Carrier Proteins , Rutin , Rutin/pharmacology , Carrier Proteins/metabolism , Carrier Proteins/genetics , Humans , Animals , Apoptosis/drug effects , Hepatocytes/drug effects , Hepatocytes/metabolism , Liver/drug effects , Liver/metabolism , Liver/pathology , Mice , Chemical and Drug Induced Liver Injury/metabolism , Chemical and Drug Induced Liver Injury/prevention & control , Chemical and Drug Induced Liver Injury/genetics , Male
16.
Biochemistry ; 63(10): 1270-1277, 2024 May 21.
Article in English | MEDLINE | ID: mdl-38770609

ABSTRACT

Cyanovirin-N (CV-N) binds high-mannose oligosaccharides on enveloped viruses with two carbohydrate-binding sites, one bearing high affinity and one low affinity to Manα(1-2)Man moieties. A tandem repeat of two CV-N molecules (CVN2) was tested for antiviral activity against human immunodeficiency virus type I (HIV-1) by using a domain-swapped dimer. CV-N was shown to bind N-acetylmannosamine (ManNAc) and N-acetyl-d-glucosamine (GlcNAc) when the carbohydrate-binding sites in CV-N were free to interact with these monosaccharides independently. CVN2 recognized ManNAc at a Kd of 1.4 µM and bound this sugar in solution, regardless of the lectin making amino acid side chain contacts on the targeted viral glycoproteins. An interdomain cross-contacting residue Glu41, which has been shown to be hydrogen bonding with dimannose, was substituted in the monomeric CV-N. The amide derivative of glucose, GlcNAc, achieved similar high affinity to the new variant CVN-E41T as high-mannose N-glycans, but binding to CVN2 in the nanomolar range with four binding sites involved or binding to the monomeric CVN-E41A. A stable dimer was engineered and expressed from the alanine-to-threonine-substituted monomer to confirm binding to GlcNAc. In summary, low-affinity binding was achieved by CVN2 to dimannosylated peptide or GlcNAc with two carbohydrate-binding sites of differing affinities, mimicking biological interactions with the respective N-linked glycans of interest and cross-linking of carbohydrates on human T cells for lymphocyte activation.


Subject(s)
Acetylglucosamine , Bacterial Proteins , Carrier Proteins , Acetylglucosamine/metabolism , Acetylglucosamine/chemistry , Binding Sites , Bacterial Proteins/chemistry , Bacterial Proteins/metabolism , Bacterial Proteins/genetics , Carrier Proteins/metabolism , Carrier Proteins/chemistry , Humans , HIV-1/metabolism , Protein Binding , Hexosamines/metabolism , Hexosamines/chemistry , Models, Molecular , Protein Multimerization
17.
Cells ; 13(10)2024 May 14.
Article in English | MEDLINE | ID: mdl-38786060

ABSTRACT

Cells defend against oxidative stress by enhancing antioxidant capacity, including stress-activated metabolic alterations, but the underlying intracellular signaling mechanisms remain unclear. This paper reports that immunoglobulin superfamily containing leucine-rich repeat (ISLR) functions as a redox sensor that responds to reactive oxygen species (ROS) stimulation and modulates the antioxidant capacity by suppressing pyruvate kinase isozyme M2 (PKM2) activity. Following oxidative stress, ISLR perceives ROS stimulation through its cysteine residue 19, and rapidly degrades in the autophagy-lysosome pathway. The downregulated ISLR enhances the antioxidant capacity by promoting the tetramerization of PKM2, and then enhancing the pyruvate kinase activity, PKM2-mediated glycolysis is crucial to the ISLR-mediated antioxidant capacity. In addition, our results demonstrated that, in triple-negative breast cancer, cisplatin treatment reduced the level of ISLR, and PKM2 inhibition sensitizes tumors to cisplatin by enhancing ROS production; and argued that PKM2 inhibition can synergize with cisplatin to limit tumor growth. Our results demonstrate a molecular mechanism by which cells respond to oxidative stress and modulate the redox balance.


Subject(s)
Antioxidants , Oxidation-Reduction , Oxidative Stress , Reactive Oxygen Species , Humans , Oxidation-Reduction/drug effects , Reactive Oxygen Species/metabolism , Cell Line, Tumor , Antioxidants/metabolism , Antioxidants/pharmacology , Oxidative Stress/drug effects , Animals , Cisplatin/pharmacology , Female , Membrane Proteins/metabolism , Thyroid Hormones/metabolism , Thyroid Hormone-Binding Proteins , Mice , Pyruvate Kinase/metabolism , Glycolysis/drug effects , Autophagy/drug effects , Carrier Proteins/metabolism , Triple Negative Breast Neoplasms/metabolism , Triple Negative Breast Neoplasms/pathology , Triple Negative Breast Neoplasms/drug therapy , Triple Negative Breast Neoplasms/enzymology
18.
J Cell Biol ; 223(6)2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38748453

ABSTRACT

There has long been conflicting evidence as to how bundled actin filaments, found in cellular structures such as filopodia, are disassembled. In this issue, Chikireddy et al. (https://doi.org/10.1083/jcb.202312106) provide a detailed in vitro analysis of the steps involved in fragmentation of fascin-bundled actin filaments and propose a novel mechanism for severing two-filament bundles.


Subject(s)
Actin Cytoskeleton , Actin Cytoskeleton/metabolism , Microfilament Proteins/metabolism , Microfilament Proteins/genetics , Actins/metabolism , Pseudopodia/metabolism , Humans , Animals , Carrier Proteins/metabolism , Carrier Proteins/genetics
19.
PLoS One ; 19(5): e0299257, 2024.
Article in English | MEDLINE | ID: mdl-38696394

ABSTRACT

BACKGROUND: Acute kidney injury (AKI) is a common and severe complication in patients treated at an Intensive Care Unit (ICU). The pathogenesis of AKI has been reported to involve hypoperfusion, diminished oxygenation, systemic inflammation, and damage by increased intracellular iron concentration. Hepcidin, a regulator of iron metabolism, has been shown to be associated with sepsis and septic shock, conditions that can result in AKI. Heparin binding protein (HBP) has been reported to be associated with sepsis and AKI. The aim of the present study was to compare serum hepcidin and heparin binding protein (HBP) levels in relation to AKI in patients admitted to the ICU. METHODS: One hundred and forty patients with community acquired illness admitted to the ICU within 24 hours after first arrival to the hospital were included in the study. Eighty five of these patients were diagnosed with sepsis and 55 with other severe non-septic conditions. Logistic and linear regression models were created to evaluate possible correlations between circulating hepcidin and heparin-binding protein (HBP), stage 2-3 AKI, peak serum creatinine levels, and the need for renal replacement therapy (RRT). RESULTS: During the 7-day study period, 52% of the 85 sepsis and 33% of the 55 non-sepsis patients had been diagnosed with AKI stage 2-3 already at inclusion. The need for RRT was 20% and 15%, respectively, in the groups. Hepcidin levels at admission were significantly higher in the sepsis group compared to the non-sepsis group but these levels did not significantly correlate to the development of stage 2-3 AKI in the sepsis group (p = 0.189) nor in the non-sepsis group (p = 0.910). No significant correlation between hepcidin and peak creatinine levels, nor with the need for RRT was observed. Stage 2-3 AKI correlated, as expected, significantly with HBP levels at admission in both groups (Odds Ratio 1.008 (CI 1.003-1.014, p = 0.005), the need for RRT, as well as with peak creatinine in septic patients. CONCLUSION: Initial serum hepcidin, and HBP levels in patients admitted to the ICU are biomarkers for septic shock but in contrast to HBP, hepcidin does not portend progression of disease into AKI or a later need for RRT. Since hepcidin is a key regulator of iron metabolism our present data do not support a decisive role of initial iron levels in the progression of septic shock into AKI.


Subject(s)
Acute Kidney Injury , Antimicrobial Cationic Peptides , Blood Proteins , Hepcidins , Shock, Septic , Humans , Acute Kidney Injury/blood , Acute Kidney Injury/etiology , Hepcidins/blood , Male , Female , Shock, Septic/blood , Shock, Septic/complications , Aged , Middle Aged , Blood Proteins/metabolism , Carrier Proteins/blood , Community-Acquired Infections/complications , Community-Acquired Infections/blood , Biomarkers/blood , Intensive Care Units , Creatinine/blood , Aged, 80 and over
20.
Sci Rep ; 14(1): 10049, 2024 05 02.
Article in English | MEDLINE | ID: mdl-38698008

ABSTRACT

Although some studies have reported on the expression and clinical significance of Fascin-1 (FSCN1) in liver cancer, the clinical application and differential diagnosis value of FSCN1 in liver cancer are still unclear. The aim of this study was to analyze the expression level of FSCN1 protein in liver cancer tissues and explore its diagnostic and application value in differentiating between hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC). The immunehistochemical analysis was used to detect the expression of FSCN1 in 108 cases of HCC, 26 cases of ICC, 23 cases of liver cirrhosis, and 11 cases of normal liver tissues. The differences in the positive expression rate and strong positive expression rate of FSCN1 among different groups were analyzed. The positive rate of FSCN1 in normal liver tissues, liver cirrhosis, HCC, and ICC tissues was 0.0% (0/11), 0.0% (0/23), 13.9% (15/108), and 92.3% (24/26), respectively, while the strong positive rate was 0.0% (0/11), 0.0% (0/23), 0.9% (1/108), and 69.2% (18/26), respectively. Both the positive rate and strong positive rate of FSCN1 in ICC tissues were significantly higher than those in HCC, liver cirrhosis, and normal liver tissues. Additionally, the positive rate of FSCN1 in moderately to poorly differentiated HCC tissues was 18.8% (15/80), significantly higher than in well-differentiated HCC (0.0%, 0/28) (P = 0.031). In liver cancer, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of FSCN1 positive prediction for ICC were 92.3%, 86.1%, 61.5%, and 97.9%, respectively, whereas the sensitivity, specificity, PPV, and NPV of FSCN1 strong positive prediction for ICC were 69.2%, 99.1%, 94.7%, and 93.0%, respectively. These results suggest that FSCN1 may play an important role in the occurrence and progression of liver cancer, and it can be used as a novel diagnostic marker for ICC.


Subject(s)
Biomarkers, Tumor , Carcinoma, Hepatocellular , Carrier Proteins , Cholangiocarcinoma , Liver Neoplasms , Microfilament Proteins , Humans , Liver Neoplasms/diagnosis , Liver Neoplasms/metabolism , Microfilament Proteins/metabolism , Carrier Proteins/metabolism , Male , Female , Middle Aged , Carcinoma, Hepatocellular/diagnosis , Carcinoma, Hepatocellular/metabolism , Biomarkers, Tumor/metabolism , Cholangiocarcinoma/diagnosis , Cholangiocarcinoma/metabolism , Aged , Adult , Liver Cirrhosis/diagnosis , Liver Cirrhosis/metabolism , Diagnosis, Differential , Bile Duct Neoplasms/diagnosis , Bile Duct Neoplasms/metabolism , Bile Duct Neoplasms/pathology , Sensitivity and Specificity
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