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1.
Cell ; 163(4): 999-1010, 2015 Nov 05.
Article in English | MEDLINE | ID: mdl-26593424

ABSTRACT

Protein translation typically begins with the recruitment of the 43S ribosomal complex to the 5' cap of mRNAs by a cap-binding complex. However, some transcripts are translated in a cap-independent manner through poorly understood mechanisms. Here, we show that mRNAs containing N(6)-methyladenosine (m(6)A) in their 5' UTR can be translated in a cap-independent manner. A single 5' UTR m(6)A directly binds eukaryotic initiation factor 3 (eIF3), which is sufficient to recruit the 43S complex to initiate translation in the absence of the cap-binding factor eIF4E. Inhibition of adenosine methylation selectively reduces translation of mRNAs containing 5'UTR m(6)A. Additionally, increased m(6)A levels in the Hsp70 mRNA regulate its cap-independent translation following heat shock. Notably, we find that diverse cellular stresses induce a transcriptome-wide redistribution of m(6)A, resulting in increased numbers of mRNAs with 5' UTR m(6)A. These data show that 5' UTR m(6)A bypasses 5' cap-binding proteins to promote translation under stresses.


Subject(s)
Adenosine/analogs & derivatives , Peptide Chain Initiation, Translational , Protein Biosynthesis , 5' Untranslated Regions , Adenosine/metabolism , Animals , Embryo, Mammalian/metabolism , Eukaryotic Initiation Factor-3/metabolism , Eukaryotic Initiation Factor-4E/metabolism , Fibroblasts/metabolism , HSP72 Heat-Shock Proteins/metabolism , HeLa Cells , Humans , Mice , Ribosomes/metabolism
2.
EMBO Rep ; 25(3): 1055-1074, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38351372

ABSTRACT

Activation of hepatic stellate cells (HSCs) plays a critical role in liver fibrosis. However, the molecular basis for HSC activation remains poorly understood. Herein, we demonstrate that primary cilia are present on quiescent HSCs but exhibit a significant loss upon HSC activation which correlates with decreased levels of the ciliary protein intraflagellar transport 88 (IFT88). Ift88-knockout mice are more susceptible to chronic carbon tetrachloride-induced liver fibrosis. Mechanistic studies show that the X-linked inhibitor of apoptosis (XIAP) functions as an E3 ubiquitin ligase for IFT88. Transforming growth factor-ß (TGF-ß), a profibrotic factor, enhances XIAP-mediated ubiquitination of IFT88, promoting its proteasomal degradation. Blocking XIAP-mediated IFT88 degradation ablates TGF-ß-induced HSC activation and liver fibrosis. These findings reveal a previously unrecognized role for ciliary homeostasis in regulating HSC activation and identify the XIAP-IFT88 axis as a potential therapeutic target for liver fibrosis.


Subject(s)
Cilia , Liver Cirrhosis , Animals , Mice , Cilia/metabolism , Hepatic Stellate Cells/metabolism , Hepatic Stellate Cells/pathology , Liver/metabolism , Liver Cirrhosis/chemically induced , Liver Cirrhosis/metabolism , Liver Cirrhosis/pathology , Transforming Growth Factor beta/metabolism
3.
Mol Cell ; 69(4): 636-647.e7, 2018 02 15.
Article in English | MEDLINE | ID: mdl-29429926

ABSTRACT

The integrated stress response (ISR) facilitates cellular adaptation to stress conditions via the common target eIF2α. During ISR, the selective translation of stress-related mRNAs often relies on alternative mechanisms, such as leaky scanning or reinitiation, but the underlying mechanism remains incompletely understood. Here we report that, in response to amino acid starvation, the reinitiation of ATF4 is not only governed by the eIF2α signaling pathway, but is also subjected to regulation by mRNA methylation in the form of N6-methyladenosine (m6A). While depleting m6A demethylases represses ATF4 reinitiation, knocking down m6A methyltransferases promotes ATF4 translation. We demonstrate that m6A in the 5' UTR controls ribosome scanning and subsequent start codon selection. Global profiling of initiating ribosomes reveals widespread alternative translation events influenced by dynamic mRNA methylation. Consistently, Fto transgenic mice manifest enhanced ATF4 expression, highlighting the critical role of m6A in translational regulation of ISR at cellular and organismal levels.


Subject(s)
Adenosine/analogs & derivatives , Alpha-Ketoglutarate-Dependent Dioxygenase FTO/physiology , Eukaryotic Initiation Factor-2/metabolism , Peptide Chain Initiation, Translational , RNA, Messenger/genetics , Ribosomes/physiology , Stress, Physiological , 5' Untranslated Regions , Adenosine/pharmacology , Animals , Cells, Cultured , Codon, Initiator , Eukaryotic Initiation Factor-2/genetics , Fibroblasts , Gene Expression Regulation , HEK293 Cells , Humans , Mice , Mice, Transgenic , Phosphorylation , RNA, Messenger/metabolism
4.
Proc Natl Acad Sci U S A ; 120(1): e2211258120, 2023 01 03.
Article in English | MEDLINE | ID: mdl-36577063

ABSTRACT

The retromer is a heteromeric protein complex that localizes to endosomal membranes and drives the formation of endosomal tubules that recycle membrane protein cargoes. In plants, the retromer plays essential and canonical functions in regulating the transport of vacuolar storage proteins and the recycle of endocytosed plasma membrane proteins (PM); however, the mechanisms underlying the regulation of assembly, protein stability, and membrane recruitment of the plant retromer complex remain to be elucidated. In this study, we identify a plant-unique endosomal regulator termed BLISTER (BLI), which colocalizes and associates with the retromer complex by interacting with the retromer core subunits VPS35 and VPS29. Depletion of BLI perturbs the assembly and membrane recruitment of the retromer core VPS26-VPS35-VPS29 trimer. Consequently, depletion of BLI disrupts retromer-regulated endosomal trafficking function, including transport of soluble vacuolar proteins and recycling of endocytosed PIN-FORMED (PIN) proteins from the endosomes back to the PM. Moreover, genetic analysis in Arabidopsis thaliana mutants reveals BLI and core retromer interact genetically in the regulation of endosomal trafficking. Taken together, we identified BLI as a plant-specific endosomal regulator, which functions in retromer pathway to modulate the recycling of endocytosed PM proteins and the trafficking of soluble vacuolar cargoes.


Subject(s)
Arabidopsis , Plant Proteins , Plant Proteins/genetics , Plant Proteins/metabolism , Protein Transport , Endosomes/metabolism , Vacuoles/metabolism , Cell Membrane/metabolism , Membrane Proteins/genetics , Membrane Proteins/metabolism , Arabidopsis/metabolism , Sorting Nexins/metabolism
5.
J Biol Chem ; 300(9): 107672, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39128723

ABSTRACT

The ubiquitin-proteasome system (UPS), which involves E3 ligases and deubiquitinates (DUBs), is critical for protein homeostasis. The epigenetic reader ZMYND8 (zinc finger MYND-type containing 8) has emerged as an oncoprotein, and its protein levels are elevated in various types of cancer, including breast cancer. However, the mechanism by which ZMYND8 protein levels are increased in cancer remains elusive. Although ZMYND8 has been reported to be regulated by the E3 ligase FBXW7, it is still unknown whether ZMYND8 could be modulated by DUBs. Here, we identified USP7 (ubiquitin carboxyl-terminal hydrolase 7) as a bona fide DUB for ZMYND8. Mechanically, USP7 directly binds to the PBP (PHD-BRD-PWWP) domain of ZMYND8 via its TRAF (tumor necrosis factor receptor-associated factor) domain and UBL (ubiquitin-like) domain and removes F-box and WD repeat domain containing 7 (FBXW7)-catalyzed poly-ubiquitin chains on lysine residue 1034 (K1034) within ZMYND8, thereby stabilizing ZMYND8 and stimulating the transcription of ZMYND8 target genes ZEB1 (zinc finger E-box binding homeobox 1) and VEGFA (Vascular Endothelial Growth Factor A). Consequently, USP7 enhances the capacity of breast cancer cells for migration and invasion through antagonizing FBXW7-mediated ZMYND8 degradation. Importantly, the protein levels of USP7 positively correlates with those of ZMYND8 in breast cancer tissues. These findings delineate an important layer of migration and invasion regulation by the USP7-ZMYND8 axis in breast cancer cells.


Subject(s)
Breast Neoplasms , Cell Movement , Neoplasm Invasiveness , Ubiquitin-Specific Peptidase 7 , Ubiquitination , Humans , Breast Neoplasms/metabolism , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Ubiquitin-Specific Peptidase 7/metabolism , Ubiquitin-Specific Peptidase 7/genetics , Female , Cell Line, Tumor , Epigenesis, Genetic , HEK293 Cells , F-Box-WD Repeat-Containing Protein 7/metabolism , F-Box-WD Repeat-Containing Protein 7/genetics , Tumor Suppressor Proteins
6.
J Cell Sci ; 136(3)2023 02 01.
Article in English | MEDLINE | ID: mdl-36752106

ABSTRACT

Cilia are surface-exposed organelles that provide motility and sensory functions for cells, and it is widely believed that mechanosensation can be mediated through cilia. Polycystin-1 and -2 (PC-1 and PC-2, respectively) are transmembrane proteins that can localize to cilia; however, the molecular mechanisms by which polycystins contribute to mechanosensation are still controversial. Studies detail two prevailing models for the molecular roles of polycystins on cilia; one stresses the mechanosensation capabilities and the other unveils their ligand-receptor nature. The discovery that polycystins interact with mastigonemes, the 'hair-like' protrusions of flagella, is a novel finding in identifying the interactors of polycystins in cilia. While the functions of polycystins proposed by both models may coexist in cilia, it is hoped that a precise understanding of the mechanism of action of polycystins can be achieved by uncovering their distribution and interacting factors inside cilia. This will hopefully provide a satisfying answer to the pathogenesis of autosomal dominant polycystic kidney disease (ADPKD), which is caused by mutations in PC-1 and PC-2. In this Review, we discuss the characteristics of polycystins in the context of cilia and summarize the functions of mastigonemes in unicellular ciliates. Finally, we compare flagella and molecular features of PC-2 between unicellular and multicellular organisms, with the aim of providing new insights into the ciliary roles of polycystins in general.


Subject(s)
Cilia , Polycystic Kidney, Autosomal Dominant , Humans , Cilia/metabolism , TRPP Cation Channels/genetics , Polycystic Kidney, Autosomal Dominant/genetics , Mutation
7.
Brief Bioinform ; 24(3)2023 05 19.
Article in English | MEDLINE | ID: mdl-37078688

ABSTRACT

The critical first step in Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-associated (CRISPR-Cas) protein-mediated gene editing is recognizing a preferred protospacer adjacent motif (PAM) on target DNAs by the protein's PAM-interacting amino acids (PIAAs). Thus, accurate computational modeling of PAM recognition is useful in assisting CRISPR-Cas engineering to relax or tighten PAM requirements for subsequent applications. Here, we describe a universal computational protein design framework (UniDesign) for designing protein-nucleic acid interactions. As a proof of concept, we applied UniDesign to decode the PAM-PIAA interactions for eight Cas9 and two Cas12a proteins. We show that, given native PIAAs, the UniDesign-predicted PAMs are largely identical to the natural PAMs of all Cas proteins. In turn, given natural PAMs, the computationally redesigned PIAA residues largely recapitulated the native PIAAs (74% and 86% in terms of identity and similarity, respectively). These results demonstrate that UniDesign faithfully captures the mutual preference between natural PAMs and native PIAAs, suggesting it is a useful tool for engineering CRISPR-Cas and other nucleic acid-interacting proteins. UniDesign is open-sourced at https://github.com/tommyhuangthu/UniDesign.


Subject(s)
CRISPR-Cas Systems , Nucleic Acids , Gene Editing , DNA/genetics
8.
Acc Chem Res ; 57(17): 2572-2581, 2024 Sep 03.
Article in English | MEDLINE | ID: mdl-39159428

ABSTRACT

ConspectusElectrides make up a fascinating group of materials with unique physical and chemical properties. In these materials, excess electrons do not behave like normal electrons in metals or form any chemical bonds with atoms. Instead, they "float" freely in the gaps within the material's structure, acting like negatively charged particles called anions (see the graph). Recently, there has been a surge of interest in van der Waals (vdW) electrides or electrenes in two dimensions. A typical example is layered lanthanum bromide (LaBr2), which can be taken as [La3+(Br1-)2]+•(e-). Each excess free electron is trapped within a hexagonal pore, forming dense dots of electron density. These anionic electrons are loosely bound, giving vdW electrides some unique properties such as ferromagnetism, superconductivity, topological features, and Dirac plasmons. The high density of the free electron makes electrides very promising for applications in thermionic emission, organic light-emitting diodes, and high-performance catalysts.In this Account, we first discuss the discovery of numerous vdW electrides through high-throughput computational screening of over 67,000 known inorganic crystals in Materials Project. A dozen of them have been newly discovered and have not been reported before. Importantly, they possess completely different structural prototypes and properties of anionic electrons compared to widely studied electrides such as Ca2N. Finding these new vdW electrides expands the variety of electrides that can be made in the experiment and opens up new possibilities for studying their unique properties and applications.Then, based on the screened vdW electrides, we delve into their various emerging properties. For example, we developed a new magnetic mechanism specific to atomic-orbital-free ferromagnetism in electrides. We uncover the dual localized and extended nature of the anionic electrons in such electrides and demonstrate the formation of the local moment by the localized feature and the ferromagnetic interaction by the direct overlapping of their extended states. We further show the effective tuning of the magnetic properties of vdW electrides by engineering their structural, electronic, and compositional properties. Besides, we show that the complex interaction between the multiple quantum orderings in vdW electrides leads to many interesting properties including valley polarization, charge density waves, a topological property, a superconducting property, and a thermoelectrical property.Moreover, we discuss strategies to leverage the unique intrinsic properties of vdW electrides for practical applications. We show that these properties make vdW electrides potential candidates for advanced applications such as spin-orbit torque memory devices, valleytronic devices, K-ion batteries, and thermoelectricity. Finally, we discuss the current challenges and future perspectives for research using these emerging materials.

9.
EMBO Rep ; 24(10): e56009, 2023 10 09.
Article in English | MEDLINE | ID: mdl-37642636

ABSTRACT

Hematopoietic stem and progenitor cells (HSPCs) are cells mainly present in the bone marrow and capable of forming mature blood cells. However, the epigenetic mechanisms governing the homeostasis of HSPCs remain elusive. Here, we demonstrate an important role for histone deacetylase 6 (HDAC6) in regulating this process. Our data show that the percentage of HSPCs in Hdac6 knockout mice is lower than in wild-type mice due to decreased HSPC proliferation. HDAC6 interacts with isocitrate dehydrogenase 1 (IDH1) and deacetylates IDH1 at lysine 233. The deacetylation of IDH1 inhibits its catalytic activity and thereby decreases the 5-hydroxymethylcytosine level of ten-eleven translocation 2 (TET2) target genes, changing gene expression patterns to promote the proliferation of HSPCs. These findings uncover a role for HDAC6 and IDH1 in regulating the homeostasis of HSPCs and may have implications for the treatment of hematological diseases.


Subject(s)
Bone Marrow , Hematopoietic Stem Cells , Animals , Mice , Histone Deacetylase 6/genetics , Histone Deacetylase 6/metabolism , Hematopoietic Stem Cells/metabolism , Bone Marrow Cells/metabolism , Homeostasis
10.
Mol Cell ; 68(3): 504-514.e7, 2017 11 02.
Article in English | MEDLINE | ID: mdl-29107534

ABSTRACT

In eukaryotic cells, protein synthesis typically begins with the binding of eIF4F to the 7-methylguanylate (m7G) cap found on the 5' end of the majority of mRNAs. Surprisingly, overall translational output remains robust under eIF4F inhibition. The broad spectrum of eIF4F-resistant translatomes is incompatible with cap-independent translation mediated by internal ribosome entry sites (IRESs). Here, we report that N6-methyladenosine (m6A) facilitates mRNA translation that is resistant to eIF4F inactivation. Depletion of the methyltransferase METTL3 selectively inhibits translation of mRNAs bearing 5' UTR methylation, but not mRNAs with 5' terminal oligopyrimidine (TOP) elements. We identify ABCF1 as a critical mediator of m6A-promoted translation under both stress and physiological conditions. Supporting the role of ABCF1 in m6A-facilitated mRNA translation, ABCF1-sensitive transcripts largely overlap with METTL3-dependent mRNA targets. By illustrating the scope and mechanism of eIF4F-independent mRNA translation, these findings reshape our current perceptions of cellular translational pathways.


Subject(s)
Adenosine/analogs & derivatives , Eukaryotic Initiation Factor-4F/metabolism , Peptide Chain Initiation, Translational/drug effects , RNA Caps/genetics , RNA, Messenger/metabolism , 5' Untranslated Regions/genetics , ATP-Binding Cassette Transporters/genetics , ATP-Binding Cassette Transporters/metabolism , Adenosine/pharmacology , Eukaryotic Initiation Factor-4F/genetics , HeLa Cells , Humans , Internal Ribosome Entry Sites , Methyltransferases/genetics , Methyltransferases/metabolism , RNA Caps/drug effects , RNA, Messenger/genetics
11.
Mol Cell ; 68(5): 993-1005.e9, 2017 Dec 07.
Article in English | MEDLINE | ID: mdl-29107537

ABSTRACT

Gene expression can be post-transcriptionally regulated via dynamic and reversible RNA modifications. N1-methyladenosine (m1A) is a recently identified mRNA modification; however, little is known about its precise location and biogenesis. Here, we develop a base-resolution m1A profiling method, based on m1A-induced misincorporation during reverse transcription, and report distinct classes of m1A methylome in the human transcriptome. m1A in 5' UTR, particularly those at the mRNA cap, associate with increased translation efficiency. A different, small subset of m1A exhibit a GUUCRA tRNA-like motif, are evenly distributed in the transcriptome, and are dependent on the methyltransferase TRMT6/61A. Additionally, we show that m1A is prevalent in the mitochondrial-encoded transcripts. Manipulation of m1A level via TRMT61B, a mitochondria-localizing m1A methyltransferase, demonstrates that m1A in mitochondrial mRNA interferes with translation. Collectively, our approaches reveal distinct classes of m1A methylome and provide a resource for functional studies of m1A-mediated epitranscriptomic regulation.


Subject(s)
Adenosine/analogs & derivatives , Cell Nucleus/metabolism , Mitochondria/metabolism , RNA Processing, Post-Transcriptional , RNA, Messenger/metabolism , RNA, Transfer/metabolism , Single Molecule Imaging/methods , 5' Untranslated Regions , Adenosine/metabolism , HEK293 Cells , Humans , Mitochondrial Proteins/biosynthesis , Mitochondrial Proteins/genetics , Nuclear Proteins/biosynthesis , Nuclear Proteins/genetics , Protein Biosynthesis , RNA Caps , RNA Interference , RNA, Messenger/genetics , RNA, Transfer/genetics , Transfection , tRNA Methyltransferases/genetics , tRNA Methyltransferases/metabolism
12.
PLoS Genet ; 18(1): e1009992, 2022 01.
Article in English | MEDLINE | ID: mdl-35007276

ABSTRACT

The gut sets the immune and metabolic parameters for the survival of commensal bacteria. We report that in Drosophila, deficiency in bacterial recognition upstream of Toll/NF-κB signalling resulted in reduced density and diversity of gut bacteria. Translational regulation factor 4E-BP, a transcriptional target of Toll/NF-κB, mediated this host-bacteriome interaction. In healthy flies, Toll activated 4E-BP, which enabled fat catabolism, which resulted in sustaining of the bacteriome. The presence of gut bacteria kept Toll signalling activity thus ensuring the feedback loop of their own preservation. When Toll activity was absent, TOR-mediated suppression of 4E-BP made fat resources inaccessible and this correlated with loss of intestinal bacterial density. This could be overcome by genetic or pharmacological inhibition of TOR, which restored bacterial density. Our results give insights into how an animal integrates immune sensing and metabolism to maintain indigenous bacteria in a healthy gut.


Subject(s)
Bacteria/growth & development , Carrier Proteins/metabolism , DNA-Binding Proteins/metabolism , Drosophila Proteins/metabolism , Drosophila melanogaster/microbiology , Toll-Like Receptors/metabolism , Transcription Factors/metabolism , Animals , Bacteria/immunology , Carrier Proteins/genetics , Drosophila melanogaster/genetics , Drosophila melanogaster/metabolism , Feedback, Physiological , Gastrointestinal Microbiome , NF-kappa B/metabolism , Signal Transduction , Symbiosis
14.
Proc Natl Acad Sci U S A ; 119(9)2022 03 01.
Article in English | MEDLINE | ID: mdl-35217618

ABSTRACT

Parkinson's disease (PD) is one of the most common neurodegenerative disorders and is characterized by loss of dopaminergic neurons in the substantia nigra (SN), causing bradykinesia and rest tremors. Although the molecular mechanism of PD is still not fully understood, neuroinflammation has a key role in the damage of dopaminergic neurons. Herein, we found that kurarinone, a unique natural product from Sophora flavescens, alleviated the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced behavioral deficits and dopaminergic neurotoxicity, including the losses of neurotransmitters and tyrosine hydroxylase (TH)-positive cells (SN and striatum [STR]). Furthermore, kurarinone attenuated the MPTP-mediated neuroinflammation via suppressing the activation of microglia involved in the nuclear factor kappa B signaling pathway. The proteomics result of the solvent-induced protein precipitation and thermal proteome profiling suggest that the soluble epoxide hydrolase (sEH) enzyme, which is associated with the neuroinflammation of PD, is a promising target of kurarinone. This is supported by the increase of plasma epoxyeicosatrienoic acids (sEH substrates) and the decrease of dihydroxyeicosatrienoic acids (sEH products), and the results of in vitro inhibition kinetics, surface plasmon resonance, and cocrystallization of kurarinone with sEH revealed that this natural compound is an uncompetitive inhibitor. In addition, sEH knockout (KO) attenuated the progression of PD, and sEH KO plus kurarinone did not further reduce the protection of PD in MPTP-induced PD mice. These findings suggest that kurarinone could be a potential natural candidate for the treatment of PD, possibly through sEH inhibition.


Subject(s)
Epoxide Hydrolases/metabolism , Flavonoids/therapeutic use , Parkinson Disease/prevention & control , 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine/pharmacology , Animals , Disease Models, Animal , Epoxide Hydrolases/genetics , Gene Deletion , Mice , Microglia/drug effects , Substrate Specificity
15.
J Proteome Res ; 23(10): 4433-4442, 2024 Oct 04.
Article in English | MEDLINE | ID: mdl-39287518

ABSTRACT

Preeclampsia, a significant cause of maternal and perinatal morbidity and mortality, remains poorly understood, in terms of its pathogenesis. This study aims to uncover novel and effective biomarkers for preeclampsia by conducting a comparative analysis of differential proteins in placentas from early onset preeclampsia (EOPE) and normal pregnancies. Utilizing tandem mass tag (TMT)-based quantitative proteomics, we identified differentially expressed proteins in placental tissues from 15 EOPE patients and 15 normal pregnant women. These proteins were subsequently validated by using parallel reaction monitoring (PRM). Our analysis revealed a total of 59 differentially expressed proteins, with 25 up-regulated and 34 down-regulated proteins in EOPE placental tissues compared to those from normal pregnancies. Validation through PRM confirmed the differential expression of 6 proteins. Our findings suggest these 6 proteins could play crucial roles in the pathogenesis of EOPE, highlighting the potential involvement of the estrogen signaling pathway and dilated cardiomyopathy (DCM) pathway in the development of preeclampsia. The data were deposited with the ProteomeXchange Consortium via the iProX partner repository with the identifier PXD055025.


Subject(s)
Placenta , Pre-Eclampsia , Proteomics , Humans , Pre-Eclampsia/metabolism , Pre-Eclampsia/pathology , Pregnancy , Female , Placenta/metabolism , Proteomics/methods , Adult , Biomarkers/metabolism , Biomarkers/analysis , Proteome/analysis , Proteome/metabolism , Tandem Mass Spectrometry , Up-Regulation
16.
Carcinogenesis ; 45(3): 170-180, 2024 03 11.
Article in English | MEDLINE | ID: mdl-38195111

ABSTRACT

Approximately 50% of colorectal cancer (CRC) patients would develop metastasis with poor prognosis, therefore, it is necessary to effectively predict metastasis in clinical treatment. In this study, we aimed to establish a machine-learning model for predicting metastasis in CRC patients by considering radiomics and transcriptomics simultaneously. Here, 1023 patients with CRC from three centers were collected and divided into five queues (Dazhou Central Hospital n = 517, Nanchong Central Hospital n = 120 and the Cancer Genome Atlas (TCGA) n = 386). A total of 854 radiomics features were extracted from tumor lesions on CT images, and 217 differentially expressed genes were obtained from non-metastasis and metastasis tumor tissues using RNA sequencing. Based on radiotranscriptomic (RT) analysis, a novel RT model was developed and verified through genetic algorithms (GA). Interleukin (IL)-26, a biomarker in RT model, was verified for its biological function in CRC metastasis. Furthermore, 15 radiomics variables were screened through stepwise regression, which was highly correlated with the IL26 expression level. Finally, a radiomics model (RA) was established by combining GA and stepwise regression analysis with radiomics features. The RA model exhibited favorable discriminatory ability and accuracy for metastasis prediction in two independent verification cohorts. We designed multicenter, multi-scale cohorts to construct and verify novel combined radiomics and genomics models for predicting metastasis in CRC. Overall, RT model and RA model might help clinicians in directing personalized diagnosis and therapeutic regimen selection for patients with CRC.


Subject(s)
Colorectal Neoplasms , Radiomics , Humans , Prognosis , Genomics , Gene Expression , Colorectal Neoplasms/diagnostic imaging , Colorectal Neoplasms/genetics
17.
J Cell Mol Med ; 28(9): e18259, 2024 May.
Article in English | MEDLINE | ID: mdl-38676364

ABSTRACT

Mechanical ventilation (MV) is an essential life-saving technique, but prolonged MV can cause significant diaphragmatic dysfunction due to atrophy and decreased contractility of the diaphragm fibres, called ventilator-induced diaphragmatic dysfunction (VIDD). It is not clear about the mechanism of occurrence and prevention measures of VIDD. Irisin is a newly discovered muscle factor that regulates energy metabolism. Studies have shown that irisin can exhibit protective effects by downregulating endoplasmic reticulum (ER) stress in a variety of diseases; whether irisin plays a protective role in VIDD has not been reported. Sprague-Dawley rats were mechanically ventilated to construct a VIDD model, and intervention was performed by intravenous administration of irisin. Diaphragm contractility, degree of atrophy, cross-sectional areas (CSAs), ER stress markers, AMPK protein expression, oxidative stress indicators and apoptotic cell levels were measured at the end of the experiment.Our findings showed that as the duration of ventilation increased, the more severe the VIDD was, the degree of ER stress increased, and the expression of irisin decreased.ER stress may be one of the causes of VIDD. Intervention with irisin ameliorated VIDD by reducing the degree of ER stress, attenuating oxidative stress, and decreasing the apoptotic index. MV decreases the expression of phosphorylated AMPK in the diaphragm, whereas the use of irisin increases the expression of phosphorylated AMPK. Irisin may exert its protective effect by activating the phosphorylated AMPK pathway.


Subject(s)
AMP-Activated Protein Kinases , Apoptosis , Diaphragm , Endoplasmic Reticulum Stress , Fibronectins , Animals , Male , Rats , AMP-Activated Protein Kinases/metabolism , Diaphragm/metabolism , Fibronectins/metabolism , Muscle Contraction , Oxidative Stress , Rats, Sprague-Dawley , Respiration, Artificial/adverse effects
18.
J Cell Physiol ; 239(4): e31195, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38230579

ABSTRACT

Phosphatidylinositol 4-kinase beta (PI4KB) is a member of the PI4K family, which is mainly enriched and functions in the Golgi apparatus. The kinase domain of PI4KB catalyzes the phosphorylation of phosphatidylinositol to form phosphatidylinositol 4-phosphate, a process that regulates various sub-cellular events, such as non-vesicular cholesterol and ceramide transport, protein glycosylation, and vesicle transport, as well as cytoplasmic division. In this study, a strain of PI4KB knockout mouse, immunofluorescence, reverse transcription polymerase chain reaction and microinjection were used to characterize the cytological location and biological function of PI4KB in the mouse embryos. we found that knocking down Pi4kb in mouse embryos resulted in embryonic lethality at around embryonic day (E) 7.5. Additionally, we observed dramatic fluctuations in PI4KB expression during the development of preimplantation embryos, with high expression in the 4-cell and morula stages. PI4KB colocalized with the Golgi marker protein TGN46 in the perinuclear and cytoplasmic regions in early blastomeres. Postimplantation, PI4KB was highly expressed in the epiblast of E7.5 embryos. Treatment of embryos with PI4KB inhibitors was found to inhibit the development of the morula into a blastocyst and the normal progression of cytoplasmic division during the formation of a 4-cell embryo. These findings suggest that PI4KB plays an important role in mouse embryogenesis by regulating various intracellular vital functions of embryonic cells.


Subject(s)
1-Phosphatidylinositol 4-Kinase , Embryonic Development , Animals , Mice , 1-Phosphatidylinositol 4-Kinase/genetics , 1-Phosphatidylinositol 4-Kinase/metabolism , Blastocyst/physiology , Embryo, Mammalian , Embryonic Development/genetics , Mice, Knockout , Mice, Inbred C57BL
19.
Pflugers Arch ; 476(11): 1677-1691, 2024 Nov.
Article in English | MEDLINE | ID: mdl-39215834

ABSTRACT

Preeclampsia (PE) is associated with increased angiotensin II sensitivity and poor neurological outcomes marked by temporal loss of neural control of blood pressure. Yet the role of centrally expressed angiotensin II type 1 receptor (AT1R) within the paraventricular nucleus of the hypothalamus (PVN) in the PE model is not understood. In a PE rat model with reduced placental perfusion pressure (RUPP) induced on gestational day 14 (GD14), the PVN expression and cellular localization of AT1R were assessed using immunofluorescence and western blotting. The sensitivity of RUPP to acute angiotensin II infusion was assessed. AT1R was antagonized by losartan (100 µg/kg/day) for 5 days intracerebroventricularly (ICV). Hemodynamic data and samples were collected on GD19 for further analysis. RUPP upregulated (p < 0.05) mRNA and protein of AT1R within the PVN and lowered (p < 0.05) circulating angiotensin II in rats. RUPP increased neural and microglial activation. Cellular localization assessment revealed that AT1R was primarily expressed in neurons and slightly in microglia and astrocytes. Infusion of 100 ng/kg as bolus increased the mean arterial pressure (MAP in mmHg) in both RUPP and Sham. ICV losartan infusion attenuated RUPP-increased MAP (113.6 ± 6.22 in RUPP vs. 92.16 ± 5.30 in RUPP + Los, p = 0.021) and the expression of nuclear transcription factor NF-κB, tyrosine hydroxylase (TH), NADPH oxidase 4 (NOX4) and reactive oxygen species (ROS) in the PVN. Our data suggest that centrally expressed AT1R, within the PVN, contributes to placental ischemia-induced hypertension in RUPP rats highlighting its therapeutic potential in PE.


Subject(s)
Angiotensin II , Losartan , Paraventricular Hypothalamic Nucleus , Placenta , Rats, Sprague-Dawley , Receptor, Angiotensin, Type 1 , Animals , Paraventricular Hypothalamic Nucleus/metabolism , Paraventricular Hypothalamic Nucleus/drug effects , Pregnancy , Receptor, Angiotensin, Type 1/metabolism , Receptor, Angiotensin, Type 1/genetics , Female , Rats , Placenta/metabolism , Placenta/drug effects , Losartan/pharmacology , Angiotensin II/pharmacology , Hypertension/metabolism , Hypertension/physiopathology , Ischemia/metabolism , Pre-Eclampsia/metabolism , Pre-Eclampsia/physiopathology , Angiotensin II Type 1 Receptor Blockers/pharmacology , Up-Regulation , Blood Pressure/drug effects
20.
Neuroimage ; 292: 120599, 2024 Apr 15.
Article in English | MEDLINE | ID: mdl-38608799

ABSTRACT

This study aimed to investigate altered static and dynamic functional network connectivity (FNC) and its correlation with clinical symptoms in patients with knee osteoarthritis (KOA). One hundred and fifty-nine patients with KOA and 73 age- and gender-matched healthy subjects (HS) underwent resting-state functional magnetic resonance imaging (rs-fMRI) and clinical evaluations. Group independent component analysis (GICA) was applied, and seven resting-state networks were identified. Patients with KOA had decreased static FNC within the default mode network (DM), visual network (VS), and cerebellar network (CB) and increased static FNC between the subcortical network (SC) and VS (p < 0.05, FDR corrected). Four reoccurring FNC states were identified using k-means clustering analysis. Although abnormalities in dynamic FNCs of KOA patients have been found using the common window size (22 TR, 44 s), but the results of the clustering analysis were inconsistent when using different window sizes, suggesting dynamic FNCs might be an unstable method to compare brain function between KOA patients and HS. These recent findings illustrate that patients with KOA have a wide range of abnormalities in the static and dynamic FNCs, which provided a reference for the identification of potential central nervous therapeutic targets for KOA treatment and might shed light on the other musculoskeletal pain neuroimaging studies.


Subject(s)
Brain , Magnetic Resonance Imaging , Nerve Net , Osteoarthritis, Knee , Humans , Magnetic Resonance Imaging/methods , Female , Male , Osteoarthritis, Knee/diagnostic imaging , Osteoarthritis, Knee/physiopathology , Middle Aged , Nerve Net/diagnostic imaging , Nerve Net/physiopathology , Aged , Brain/diagnostic imaging , Brain/physiopathology , Adult , Connectome/methods , Rest , Brain Mapping/methods
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