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Effect of apigetrin in pseudo-SARS-CoV-2-induced inflammatory and pulmonary fibrosis in vitro model.Scientific Reports Jun 2024SARS-CoV-2 has become a global public health problem. Acute respiratory distress syndrome (ARDS) is the leading cause of death due to the SARS-CoV-2 infection. Pulmonary...
SARS-CoV-2 has become a global public health problem. Acute respiratory distress syndrome (ARDS) is the leading cause of death due to the SARS-CoV-2 infection. Pulmonary fibrosis (PF) is a severe and frequently reported COVID-19 sequela. In this study, an in vitro model of ARDS and PF caused by SARS-CoV-2 was established in MH-S, THP-1, and MRC-5 cells using pseudo-SARS-CoV-2 (PSCV). Expression of proinflammatory cytokines (IL-6, IL-1β, and TNF-α) and HIF-1α was increased in PSCV-infected MH-S and THP-1 cells, ARDS model, consistent with other profiling data in SARS-CoV-2-infected patients have been reported. Hypoxia-inducible factor-1 alpha (HIF-1α) siRNA and cobalt chloride were tested using this in vitro model. HIF-1α knockdown reduces inflammation caused by PSCV infection in MH-S and THP-1 cells and lowers elevated levels of CTGF, COLA1, and α-SMA in MRC-5 cells exposed to CPMSCV. Furthermore, apigetrin, a glycoside bioactive dietary flavonoid derived from several plants, including Crataegus pinnatifida, which is reported to be a HIF-1α inhibitor, was tested in this in vitro model. Apigetrin significantly reduced the increased inflammatory cytokine (IL-6, IL-1β, and TNF-α) expression and secretion by PSCV in MH-S and THP-1 cells. Apigetrin inhibited the binding of the SARS-CoV-2 spike protein RBD to the ACE2 protein. An in vitro model of PF induced by SARS-CoV-2 was produced using a conditioned medium of THP-1 and MH-S cells that were PSCV-infected (CMPSCV) into MRC-5 cells. In a PF model, CMPSCV treatment of THP-1 and MH-S cells increased cell growth, migration, and collagen synthesis in MRC-5 cells. In contrast, apigetrin suppressed the increase in cell growth, migration, and collagen synthesis induced by CMPSCV in THP-1 and MH-S MRC-5 cells. Also, compared to control, fibrosis-related proteins (CTGF, COLA1, α-SMA, and HIF-1α) levels were over two-fold higher in CMPSV-treated MRC-5 cells. Apigetrin decreased protein levels in CMPSCV-treated MRC-5 cells. Thus, our data suggest that hypoxia-inducible factor-1 alpha (HIF-1α) might be a novel target for SARS-CoV-2 sequela therapies and apigetrin, representative of HIF-1alpha inhibitor, exerts anti-inflammatory and PF effects in PSCV-treated MH-S, THP-1, and CMPVSC-treated MRC-5 cells. These findings indicate that HIF-1α inhibition and apigetrin would have a potential value in controlling SARS-CoV-2-related diseases.
Topics: Humans; Pulmonary Fibrosis; SARS-CoV-2; COVID-19; Hypoxia-Inducible Factor 1, alpha Subunit; Cytokines; Inflammation; Cell Line; Respiratory Distress Syndrome; THP-1 Cells
PubMed: 38914619
DOI: 10.1038/s41598-024-65447-w -
Nature Communications Jun 2024The NuA3 complex is a major regulator of gene transcription and the cell cycle in yeast. Five core subunits are required for complex assembly and function, but it...
The NuA3 complex is a major regulator of gene transcription and the cell cycle in yeast. Five core subunits are required for complex assembly and function, but it remains unclear how these subunits interact to form the complex. Here, we report that the Taf14 subunit of the NuA3 complex binds to two other subunits of the complex, Yng1 and Sas3, and describe the molecular mechanism by which the extra-terminal domain of Taf14 recognizes the conserved motif present in Yng1 and Sas3. Structural, biochemical, and mutational analyses show that two motifs are sandwiched between the two extra-terminal domains of Taf14. The head-to-toe dimeric complex enhances the DNA binding activity of Taf14, and the formation of the hetero-dimer involving the motifs of Yng1 and Sas3 is driven by sequence complementarity. In vivo assays in yeast demonstrate that the interactions of Taf14 with both Sas3 and Yng1 are required for proper function of the NuA3 complex in gene transcription and DNA repair. Our findings suggest a potential basis for the assembly of three core subunits of the NuA3 complex, Taf14, Yng1 and Sas3.
Topics: Saccharomyces cerevisiae Proteins; Saccharomyces cerevisiae; Protein Binding; Transcription Factor TFIID; Protein Subunits; TATA-Binding Protein Associated Factors; Histone Acetyltransferases; Protein Multimerization; Models, Molecular; Transcription, Genetic; Amino Acid Sequence
PubMed: 38914563
DOI: 10.1038/s41467-024-49730-y -
RNA Biology Jan 2024Ribosomes are large macromolecular complexes composed of both proteins and RNA, that require a plethora of factors and post-transcriptional modifications for their...
Ribosomes are large macromolecular complexes composed of both proteins and RNA, that require a plethora of factors and post-transcriptional modifications for their biogenesis. In human mitochondria, the ribosomal RNA is post-transcriptionally modified at ten sites. The N4-methylcytidine (mC) methyltransferase, METTL15, modifies the 12S rRNA of the small subunit at position C1486. The enzyme is essential for mitochondrial protein synthesis and assembly of the mitoribosome small subunit, as shown here and by previous studies. Here, we demonstrate that the mC modification is not required for small subunit biogenesis, indicating that the chaperone-like activity of the METTL15 protein itself is an essential component for mitoribosome biogenesis.
Topics: Methyltransferases; Humans; Mitochondrial Ribosomes; RNA, Ribosomal; Mitochondria; Methylation
PubMed: 38913872
DOI: 10.1080/15476286.2024.2369374 -
ELife Jun 2024Allosteric cooperativity between ATP and substrates is a prominent characteristic of the cAMP-dependent catalytic subunit of protein kinase A (PKA-C). This long-range...
Allosteric cooperativity between ATP and substrates is a prominent characteristic of the cAMP-dependent catalytic subunit of protein kinase A (PKA-C). This long-range synergistic action is involved in substrate recognition and fidelity, and it may also regulate PKA's association with regulatory subunits and other binding partners. To date, a complete understanding of this intramolecular mechanism is still lacking. Here, we integrated NMR(Nuclear Magnetic Resonance)-restrained molecular dynamics simulations and a Markov State Model to characterize the free energy landscape and conformational transitions of PKA-C. We found that the apoenzyme populates a broad free energy basin featuring a conformational ensemble of the active state of PKA-C (ground state) and other basins with lower populations (excited states). The first excited state corresponds to a previously characterized inactive state of PKA-C with the αC helix swinging outward. The second excited state displays a disrupted hydrophobic packing around the regulatory (R) spine, with a flipped configuration of the F100 and F102 residues at the αC-β4 loop. We validated the second excited state by analyzing the F100A mutant of PKA-C, assessing its structural response to ATP and substrate binding. While PKA-C preserves its catalytic efficiency with Kemptide, this mutation rearranges the αC-β4 loop conformation, interrupting the coupling of the two lobes and abolishing the allosteric binding cooperativity. The highly conserved αC-β4 loop emerges as a pivotal element to control the synergistic binding of nucleotide and substrate, explaining how mutations or insertions near or within this motif affect the function and drug sensitivity in homologous kinases.
Topics: Molecular Dynamics Simulation; Allosteric Regulation; Adenosine Triphosphate; Catalytic Domain; Cyclic AMP-Dependent Protein Kinases; Protein Conformation; Protein Binding; Nucleotides; Substrate Specificity; Cyclic AMP-Dependent Protein Kinase Catalytic Subunits
PubMed: 38913408
DOI: 10.7554/eLife.91506 -
Heliyon Jun 2024Alveolar epithelial barrier integrity is essential for lung homeostasis. Na, K-ATPase β1 subunit (ATP1B1) involves alveolar edema fluid clearance and alveolar...
AIMS
Alveolar epithelial barrier integrity is essential for lung homeostasis. Na, K-ATPase β1 subunit (ATP1B1) involves alveolar edema fluid clearance and alveolar epithelial barrier stability. However, the underlying molecular mechanism of ATP1B1 in alveolar epithelial cells still needs to be understood.
MAIN METHODS
We utilized Co-Immunoprecipitation mass spectrometry proteomic analysis, protein-protein interaction (PPI) analysis, enrichment analysis, and parallel reaction monitoring (PRM) analysis to investigate proteins interacting with ATP1B1 in A549 cells.
KEY FINDINGS
A total of 159 proteins were identified as significant proteins interacting with ATP1B1 in A549 cells. Ribosomal and heat shock proteins were major constituents of the two main functional modules based on the PPI network. Enrichment analysis showed that significant proteins were involved in protein translation, posttranslational processing, and function regulation. Moreover, 10 proteins of interest were verified by PRM, and fold changes in 6 proteins were consistent with proteomics results. Finally, HSP90AB1, EIF4A1, TUBB4B, HSPA8, STAT1, and PLEC were considered candidates for binding to ATP1B1 to function in alveolar epithelial cells.
SIGNIFICANCE
Our study provides new insights into the role of ATP1B1 in alveolar epithelial cells and indicates that six proteins, in particular HSP90AB1, may be key proteins interacting with and regulating ATP1B1, which might be potential targets for the treatment of acute respiratory distress syndrome.
PubMed: 38912441
DOI: 10.1016/j.heliyon.2024.e32579 -
Frontiers in Immunology 2024The Nipah virus (NiV), a highly deadly bat-borne paramyxovirus, poses a substantial threat due to recurrent outbreaks in specific regions, causing severe respiratory and...
The Nipah virus (NiV), a highly deadly bat-borne paramyxovirus, poses a substantial threat due to recurrent outbreaks in specific regions, causing severe respiratory and neurological diseases with high morbidity. Two distinct strains, NiV-Malaysia (NiV-M) and NiV-Bangladesh (NiV-B), contribute to outbreaks in different geographical areas. Currently, there are no commercially licensed vaccines or drugs available for prevention or treatment. In response to this urgent need for protection against NiV and related infections, we developed a novel homotypic virus-like nanoparticle (VLP) vaccine co-displaying NiV attachment glycoproteins (G) from both strains, utilizing the self-assembling properties of ferritin protein. In comparison to the NiV G subunit vaccine, our nanoparticle vaccine elicited significantly higher levels of neutralizing antibodies and provided complete protection against a lethal challenge with NiV infection in Syrian hamsters. Remarkably, the nanoparticle vaccine stimulated the production of antibodies that exhibited superior cross-reactivity to homologous or heterologous . These findings underscore the potential utility of ferritin-based nanoparticle vaccines in providing both broad-spectrum and long-term protection against NiV and emerging zoonotic challenges.
Topics: Animals; Nipah Virus; Henipavirus Infections; Ferritins; Mesocricetus; Antibodies, Viral; Antibodies, Neutralizing; Nanoparticles; Viral Vaccines; Cricetinae; Vaccines, Virus-Like Particle; Female; Humans; Nanovaccines
PubMed: 38911870
DOI: 10.3389/fimmu.2024.1387811 -
Journal of Cancer 2024Actin-related protein 2/3 complex subunit 1A (ARPC1A) is implicated in several cancers due to its critical role in regulating actin polymerization. However, the exact...
Actin-related protein 2/3 complex subunit 1A (ARPC1A) is implicated in several cancers due to its critical role in regulating actin polymerization. However, the exact mechanism of ARPC1A in cancer remains unclear. This study aims to investigate the biological role of ARPC1A in various cancers and the regulatory role of ARPC1A in glioblastoma multiforme (GBM). We analyzed the expression differences, prognostic value, mutations, immune infiltration, immune microenvironment, and single-cell level correlations of ARPC1A in various cancers. Furthermore, we employed gene set enrichment analysis (GSEA) and functional experiments to elucidate the regulatory mechanisms of ARPC1A on GBM. Importantly, we assessed the role of ARPC1A in temozolomide (TMZ) resistance of GBM. ARPC1A expression was up-regulated in most cancer tissues and was associated with poorer prognosis. Genomic mutation analysis revealed that the predominant type of ARPC1A mutation in tumors was amplification. ARPC1A expression was negatively correlated with B-cell and immune scores in most tumors. Both GSEA and single-cell sequencing have revealed that ARPC1A promotes tumor proliferation and epithelial-mesenchymal transition. experiments confirmed that ARPC1A knockdown inhibited the proliferation and metastatic ability of GBM cells. Notably, silencing ARPC1A reduced TMZ resistance in GBM cells. This study highlights the prognostic value of ARPC1A in various tumors and its potential for application in immunotherapy. Meanwhile, the modulation of GBM malignant behavior and TMZ resistance by ARPC1A provides a new approach for personalized and precise treatment of GBM.
PubMed: 38911374
DOI: 10.7150/jca.94552 -
Brain Communications 2024While voltage-gated potassium channels have critical roles in controlling neuronal excitability, they also have non-ion-conducting functions. Kv8.1, encoded by the KCNV1...
While voltage-gated potassium channels have critical roles in controlling neuronal excitability, they also have non-ion-conducting functions. Kv8.1, encoded by the KCNV1 gene, is a 'silent' ion channel subunit whose biological role is complex since Kv8.1 subunits do not form functional homotetramers but assemble with Kv2 to modify its ion channel properties. We profiled changes in ion channel expression in amyotrophic lateral sclerosis patient-derived motor neurons carrying a superoxide dismutase 1(A4V) mutation to identify what drives their hyperexcitability. A major change identified was a substantial reduction of KCNV1/Kv8.1 expression, which was also observed in patient-derived neurons with C9orf72 expansion. We then studied the effect of reducing KCNV1/Kv8.1 expression in healthy motor neurons and found it did not change neuronal firing but increased vulnerability to cell death. A transcriptomic analysis revealed dysregulated metabolism and lipid/protein transport pathways in KCNV1/Kv8.1-deficient motor neurons. The increased neuronal vulnerability produced by the loss of KCNV1/Kv8.1 was rescued by knocking down Kv2.2, suggesting a potential Kv2.2-dependent downstream mechanism in cell death. Our study reveals, therefore, unsuspected and distinct roles of Kv8.1 and Kv2.2 in amyotrophic lateral sclerosis-related neurodegeneration.
PubMed: 38911266
DOI: 10.1093/braincomms/fcae202 -
Pediatric Investigation Jun 2024Postzygotic mutations in the genes, which encode the G-protein nucleotide binding protein alpha subunits, have been identified in patients with phakomatosis...
IMPORTANCE
Postzygotic mutations in the genes, which encode the G-protein nucleotide binding protein alpha subunits, have been identified in patients with phakomatosis pigmentovascularis (PPV). However, little is known about the Chinese population.
OBJECTIVE
To identify pathogenic mutations in pediatric patients with PPV within the Chinese population.
METHODS
We performed whole-exome sequencing (WES) using skin lesion tissues from pediatric patients diagnosed with PPV. Additionally, ultradeep-targeted sequencing was conducted to validate the somatic mutations. A genotype-phenotype correlation was analyzed by integrating data from previous reports with the findings of the present study.
RESULTS
Thirteen patients were enrolled, all diagnosed with the cesioflammea type of PPV, except for one patient with an unclassifiable type. We identified somatic c.547C>T (p.R183C) variant in seven patients and c.548G>A (p.R183Q) in four patients, with low allelic fractions ranging from 2.1% to 8.6% through ultradeep sequencing. Besides, a c.548G>A (p.R183Q) variant was detected through targeted sequencing in one of two patients who did not exhibit detectable variants via WES. The genotype-phenotype correlation analysis, involving 15 patients with a variant and 10 with a variant, revealed that facial capillary malformation (87% . 50%, = 0.075) and ocular melanocytosis (80% . 40%, = 0.087) appeared to be more frequent in patients with mutation compared to those with mutations. All four patients diagnosed with cesiomarmorata type or overlapping cesioflammea and cesiomarmorata type PPV carried the variant.
INTERPRETATION
Our study demonstrated that the majority of PPV patients in the Chinese population carried a postzygotic variant of , thus further confirming the pathogenic role of mosaicism in the development of PPV cesioflammea type.
PubMed: 38910853
DOI: 10.1002/ped4.12424 -
Current Opinion in Microbiology Jun 2024Bacterial microcompartments (BMCs) are polyhedral structures that segregate enzymatic cargo from the cytosol via encapsulation within a protein shell. Unlike other... (Review)
Review
Bacterial microcompartments (BMCs) are polyhedral structures that segregate enzymatic cargo from the cytosol via encapsulation within a protein shell. Unlike other biological polyhedra, such as viral capsids and encapsulins, BMC shells can exhibit a highly advantageous structural and functional plasticity, conforming to a variety of anabolic (CO fixation in carboxysomes) and catabolic (nutrient assimilation in metabolosomes) roles. Consequently, understanding the subunit properties and associated protein-protein interaction processes that guide shell assembly and function is a necessary step to fully harness BMCs as modular, biotechnological nanomachines. Here, we describe the recent insights into the dynamics of structural features of the key BMC domain (Pfam00936)-containing proteins, which serve as a structural template for BMC-H and BMC-T shell building blocks.
PubMed: 38909546
DOI: 10.1016/j.mib.2024.102497