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1.
Clin Exp Med ; 24(1): 102, 2024 May 17.
Article En | MEDLINE | ID: mdl-38758367

Immunotherapy is widely used in cancer treatment; however, only a subset of patients responds well to it. Significant efforts have been made to identify patients who will benefit from immunotherapy. Successful anti-tumor immunity depends on an intact cancer-immunity cycle, especially long-lasting CD8+ T-cell responses. Interferon (IFN)-α/ß/IFN-γ/interleukin (IL)-15 pathways have been reported to be involved in the development of CD8+ T cells. And these pathways may predict responses to immunotherapy. Herein, we aimed to analyze multiple public databases to investigate whether IFN-α/ß/IFN-γ/IL-15 pathways could be used to predict the response to immunotherapy. Results showed that IFN-α/ß/IFN-γ/IL-15 pathways could efficiently predict immunotherapy response, and guanylate-binding protein 1 (GBP1) could represent the IFN-α/ß/IFN-γ/IL-15 pathways. In public and private cohorts, we further demonstrated that GBP1 could efficiently predict the response to immunotherapy. Functionally, GBP1 was mainly expressed in macrophages and strongly correlated with chemokines involved in T-cell migration. Therefore, our study comprehensively investigated the potential role of GBP1 in immunotherapy, which could serve as a novel biomarker for immunotherapy and a target for drug development.


GTP-Binding Proteins , Immunotherapy , Interferon-alpha , Interferon-gamma , Interleukin-15 , Neoplasms , Humans , Interleukin-15/genetics , GTP-Binding Proteins/genetics , GTP-Binding Proteins/immunology , Interferon-gamma/metabolism , Neoplasms/immunology , Neoplasms/therapy , Immunotherapy/methods , Interferon-beta , CD8-Positive T-Lymphocytes/immunology , Signal Transduction
2.
BMJ Case Rep ; 17(5)2024 May 06.
Article En | MEDLINE | ID: mdl-38719261

Olmesartan is an angiotensin II receptor blocker licensed for the treatment of hypertension. It can cause a sprue-like enteropathy (SLE), characterised by chronic diarrhoea, weight loss and villous atrophy. Transiently raised anti-tissue transglutaminase (ATTG) antibody has also been rarely reported in the literature.We describe the case of a woman in her mid-50s, who presented with a history of intermittent loose stools over 1 year, associated with significant weight loss. She had two marginally raised serum ATTG antibody tests during her work-up.After extensive investigations, she was diagnosed with olmesartan-induced enteropathy. On subsequent follow-up, her symptoms had resolved with cessation of her olmesartan therapy.This case adds to existing literature, highlighting the importance of considering olmesartan as a possible differential diagnosis for SLE. It also reports the presence of a raised ATTG antibody which is infrequently reported in this context.


Diarrhea , Imidazoles , Tetrazoles , Transglutaminases , Weight Loss , Humans , Female , Imidazoles/adverse effects , Diarrhea/chemically induced , Tetrazoles/adverse effects , Middle Aged , Transglutaminases/immunology , Diagnosis, Differential , Angiotensin II Type 1 Receptor Blockers/adverse effects , Autoantibodies/blood , Protein Glutamine gamma Glutamyltransferase 2 , Chronic Disease , Celiac Disease/diagnosis , GTP-Binding Proteins/immunology , GTP-Binding Proteins/antagonists & inhibitors
3.
Front Endocrinol (Lausanne) ; 15: 1392063, 2024.
Article En | MEDLINE | ID: mdl-38715801

Introduction: Understanding the genetic factors contributing to variations in bone mineral density (BMD) and vitamin D could provide valuable insights into the pathogenesis of osteoporosis. This study aimed to evaluate the association of single nucleotide variants in MARK3 (rs11623869), PLCB4 (rs6086746), and GEMIN2 (rs2277458) with BMD in Mexican women. Methods: The gene-gene interaction was evaluated in these variants in serum 25(OH)D levels and BMD. A genetic risk score (GRS) was created on the basis of the three genetic variants. Genotyping was performed using predesigned TaqMan assays. Results: A significant association was found between the rs6086746-A variant and BMD at the total hip, femoral neck, and lumbar spine, in women aged 45 years or older. However, no association was observed between the variants rs11623869 and rs2277458. The rs11623869 × rs2277458 interaction was associated with total hip (p=0.002) and femoral neck BMD (p=0.013). Similarly, for vitamin D levels, we observed an interaction between the variants rs6086746 × rs2277458 (p=0.021). GRS revealed a significant association with total hip BMD (p trend=0.003) and femoral neck BMD (p trend=0.006), as well as increased vitamin D levels (p trend=0.0003). These findings provide evidence of the individual and joint effect of the MARK3, PLCB4, and GEMIN2 variants on BMD and serum vitamin D levels in Mexican women. Discussion: This knowledge could help to elucidate the interaction mechanism between BMD-related genetic variants and 25OHD, contributing to the determination of the pathogenesis of osteoporosis and its potential implications during early interventions.


Bone Density , Polymorphism, Single Nucleotide , Vitamin D , Humans , Female , Bone Density/genetics , Mexico , Middle Aged , Vitamin D/blood , Vitamin D/analogs & derivatives , Protein Serine-Threonine Kinases/genetics , Osteoporosis/genetics , Osteoporosis/blood , Aged , Adult , GTP-Binding Proteins/genetics , Genetic Predisposition to Disease , Genotype
4.
Medicine (Baltimore) ; 103(18): e37847, 2024 May 03.
Article En | MEDLINE | ID: mdl-38701254

RATIONALE: Mitochondrial diseases are a group of disorders in which mutations in mitochondrial DNA or nuclear DNA lead to dysfunctional oxidative phosphorylation of cells, with mutations in mitochondrial DNA being the most common cause of mitochondrial disease, and mutations in nuclear genes being rarely reported. The echocardiographic findings of mitochondrial diseases with nuclear gene mutations in children's hearts are even rarer. Even more valuable is that we followed up the patient for 4 years and dynamically observed the cardiac echocardiographic manifestations of mitochondrial disease. Provide ideas for the clinical diagnosis and prognosis of mitochondrial diseases. PATIENT CONCERNS: The patient was seen in the pediatric outpatient clinic for poor strength and mental retardation. echocardiography: mild left ventricular (LV) enlargement and LV wall thickening. Nuclear genetic testing: uanosine triphosphate binding protein 3 (GTPBP3) gene mutation. Diagnosis of mitochondrial disease. DIAGNOSES: Mitochondrial disease with GTPBP3 gene mutations. OUTCOMES: After receiving drug treatment, the patient exhibited a reduction in lactate levels, an enhanced physical condition compared to prior assessments, and demonstrated average intellectual development. LESSONS SUBSECTIONS: For echocardiographic indications of LV wall thickening and LV enlargement, one needs to be alert to the possibility of hereditary cardiomyopathy, especially in children.


Echocardiography , Mitochondrial Diseases , Mutation , Female , Humans , Echocardiography/methods , GTP-Binding Proteins/genetics , Mitochondrial Diseases/genetics , Mitochondrial Diseases/diagnostic imaging , Mitochondrial Diseases/diagnosis , Child
5.
J Genet ; 1032024.
Article En | MEDLINE | ID: mdl-38736250

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.


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
6.
PLoS One ; 19(5): e0298864, 2024.
Article En | MEDLINE | ID: mdl-38753630

Fibrotic remodeling is the primary driver of functional loss in chronic kidney disease, with no specific anti-fibrotic agent available for clinical use. Transglutaminase 2 (TG2), a wound response enzyme that irreversibly crosslinks extracellular matrix proteins causing dysregulation of extracellular matrix turnover, is a well-characterized anti-fibrotic target in the kidney. We describe the humanization and characterization of two anti-TG2 monoclonal antibodies (zampilimab [hDC1/UCB7858] and BB7) that inhibit crosslinking by TG2 in human in vitro and rabbit/cynomolgus monkey in vivo models of chronic kidney disease. Determination of zampilimab half-maximal inhibitory concentration (IC50) against recombinant human TG2 was undertaken using the KxD assay and determination of dissociation constant (Kd) by surface plasmon resonance. Efficacy in vitro was established using a primary human renal epithelial cell model of tubulointerstitial fibrosis, to assess mature deposited extracellular matrix proteins. Proof of concept in vivo used a cynomolgus monkey unilateral ureteral obstruction model of chronic kidney disease. Zampilimab inhibited TG2 crosslinking transamidation activity with an IC50 of 0.25 nM and Kd of <50 pM. In cell culture, zampilimab inhibited extracellular TG2 activity (IC50 119 nM) and dramatically reduced transforming growth factor-ß1-driven accumulation of multiple extracellular matrix proteins including collagens I, III, IV, V, and fibronectin. Intravenous administration of BB7 in rabbits resulted in a 68% reduction in fibrotic index at Day 25 post-unilateral ureteral obstruction. Weekly intravenous administration of zampilimab in cynomolgus monkeys with unilateral ureteral obstruction reduced fibrosis at 4 weeks by >50%, with no safety signals. Our data support the clinical investigation of zampilimab for the treatment of kidney fibrosis.


Disease Models, Animal , Fibrosis , GTP-Binding Proteins , Macaca fascicularis , Protein Glutamine gamma Glutamyltransferase 2 , Renal Insufficiency, Chronic , Transglutaminases , Animals , Humans , Fibrosis/drug therapy , Rabbits , Renal Insufficiency, Chronic/drug therapy , Renal Insufficiency, Chronic/pathology , Transglutaminases/antagonists & inhibitors , Transglutaminases/metabolism , GTP-Binding Proteins/antagonists & inhibitors , GTP-Binding Proteins/metabolism , GTP-Binding Proteins/immunology , Antibodies, Monoclonal/pharmacology , Antibodies, Monoclonal/administration & dosage , Antibodies, Monoclonal, Humanized/pharmacology , Male , Kidney/pathology , Kidney/drug effects , Kidney/metabolism
7.
Biochem Pharmacol ; 224: 116190, 2024 Jun.
Article En | MEDLINE | ID: mdl-38604257

Arrestins are key negative regulators of G Protein-Coupled Receptors (GPCRs) through mediation of G protein desensitisation and receptor internalisation. Arrestins can also contribute to signal transduction by scaffolding downstream signalling effectors for activation. GPCR kinase (GRK) enzymes phosphorylate the intracellular C-terminal domain, or intracellular loop regions of GPCRs to promote arrestin interaction. There are seven different GRK subtypes, which may uniquely phosphorylate the C-terminal tail in a type of 'phosphorylation barcode,' potentially differentially contributing to arrestin translocation and arrestin-dependent signalling. Such contributions may be exploited to develop arrestin-biased ligands. Here, we examine the effect of different GRK subtypes on the ability to promote translocation of arrestin-2 and arrestin-3 to the cannabinoid CB1 receptor (CB1) with a range of ligands. We find that most GRK subtypes (including visual GRK1) can enhance arrestin-2 and -3 translocation to CB1, and that GRK-dependent changes in arrestin-2 and arrestin-3 translocation were broadly shared for most agonists tested. GRK2/3 generally enhanced arrestin translocation more than the other GRK subtypes, with some small differences between ligands. We also explore the interplay between G protein activity and GRK2/3-dependent arrestin translocation, highlighting that high-efficacy G protein agonists will cause GRK2/3 dependent arrestin translocation. This study supports the hypothesis that arrestin-biased ligands for CB1 must engage GRK5/6 rather than GRK2/3, and G protein-biased ligands must have inherently low efficacy.


Arrestins , Protein Transport , Receptor, Cannabinoid, CB1 , Signal Transduction , Humans , Receptor, Cannabinoid, CB1/metabolism , Receptor, Cannabinoid, CB1/agonists , Signal Transduction/physiology , HEK293 Cells , Arrestins/metabolism , Protein Transport/physiology , GTP-Binding Proteins/metabolism , G-Protein-Coupled Receptor Kinases/metabolism , Animals , beta-Arrestin 2/metabolism , beta-Arrestin 2/genetics
8.
Biomolecules ; 14(4)2024 Apr 19.
Article En | MEDLINE | ID: mdl-38672511

TG2 is a unique member of the transglutaminase family as it undergoes a dramatic conformational change, allowing its mutually exclusive function as either a cross-linking enzyme or a G-protein. The enzyme's dysregulated activity has been implicated in a variety of pathologies (e.g., celiac disease, fibrosis, cancer), leading to the development of a wide range of inhibitors. Our group has primarily focused on the development of peptidomimetic targeted covalent inhibitors, the nature and size of which were thought to be important features to abolish TG2's conformational dynamism and ultimately inhibit both its activities. However, we recently demonstrated that the enzyme was unable to bind guanosine triphosphate (GTP) when catalytically inactivated by small molecule inhibitors. In this study, we designed a library of models targeting covalent inhibitors of progressively smaller sizes (15 to 4 atoms in length). We evaluated their ability to inactivate TG2 by measuring their respective kinetic parameters kinact and KI. Their impact on the enzyme's ability to bind GTP was then evaluated and subsequently correlated to the conformational state of the enzyme, as determined via native PAGE and capillary electrophoresis. All irreversible inhibitors evaluated herein locked TG2 in its open conformation and precluded GTP binding. Therefore, we conclude that steric bulk and structural complexity are not necessary factors to consider when designing TG2 inhibitors to abolish G-protein activity.


Alkylating Agents , Catalytic Domain , GTP-Binding Proteins , Protein Glutamine gamma Glutamyltransferase 2 , Transglutaminases , Transglutaminases/chemistry , Transglutaminases/metabolism , Transglutaminases/antagonists & inhibitors , GTP-Binding Proteins/chemistry , GTP-Binding Proteins/metabolism , Humans , Alkylating Agents/chemistry , Alkylating Agents/pharmacology , Guanosine Triphosphate/chemistry , Guanosine Triphosphate/metabolism , Sulfhydryl Compounds/chemistry , Sulfhydryl Compounds/pharmacology , Protein Conformation , Kinetics , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology
9.
Nat Commun ; 15(1): 2900, 2024 Apr 04.
Article En | MEDLINE | ID: mdl-38575575

Currently, only Palivizumab and Nirsevimab that target the respiratory syncytical virus (RSV) fusion protein are licensed for pre-treatment of infants. Glycoprotein-targeting antibodies may also provide protection against RSV. In this study, we generate monoclonal antibodies from mice immunized with G proteins from RSV-A2 and RSV-B1 strains. These monoclonal antibodies recognize six unique antigenic classes (G0-G5). None of the anti-G monoclonal antibodies neutralize RSV-A2 or RSV-B1 in vitro. In mice challenged with either RSV-A2 line 19 F or RSV-B1, one day after treatment with anti-G monoclonal antibodies, all monoclonal antibodies reduce lung pathology and significantly reduce lung infectious viral titers by more than 2 logs on day 5 post-RSV challenge. RSV dissemination in the lungs was variable and correlated with lung pathology. We demonstrate new cross-protective anti-G monoclonal antibodies targeting multiple sites including conformation-dependent class G0 MAb 77D2, CCD-specific class G1 MAb 40D8, and carboxy terminus of CCD class G5 MAb 7H11, to support development of G-targeting monoclonal antibodies against RSV.


Respiratory Syncytial Virus Infections , Respiratory Syncytial Virus Vaccines , Respiratory Syncytial Virus, Human , Humans , Mice , Animals , Antibodies, Monoclonal , Respiratory Syncytial Virus Infections/prevention & control , Antibodies, Viral , Viral Fusion Proteins , GTP-Binding Proteins , Antibodies, Neutralizing
10.
Cell Commun Signal ; 22(1): 218, 2024 Apr 05.
Article En | MEDLINE | ID: mdl-38581012

Signal transduction through G protein-coupled receptors (GPCRs) has been a major focus in cell biology for decades. Numerous disorders are associated with GPCRs that utilize Gi proteins to inhibit adenylyl cyclase (AC) as well as regulate other effectors. Several early studies have successfully defined the AC-interacting domains of several members of Gαi by measuring the loss of activity upon homologous replacements of putative regions of constitutive active Gαi mutants. However, whether such findings can indeed be translated into the context of a receptor-activated Gαi have not been rigorously verified. To address this issue, an array of known and new chimeric mutations was introduced into GTPase-deficient Q204L (QL) and R178C (RC) mutants of Gαi1, followed by examinations on their ability to inhibit AC. Surprisingly, most chimeras failed to abolish the constitutive activity brought on by the QL mutation, while some were able to eliminate the inhibitory activity of RC mutants. Receptor-mediated inhibition of AC was similarly observed in the same chimeric constructs harbouring the pertussis toxin (PTX)-resistant C351I mutation. Moreover, RC-bearing loss-of-function chimeras appeared to be hyper-deactivated by endogenous RGS protein. Molecular docking revealed a potential interaction between AC and the α3/ß5 loop of Gαi1. Subsequent cAMP assays support a cooperative action of the α3/ß5 loop, the α4 helix, and the α4/ß6 loop in mediating AC inhibition by Gαi1-i3. Our results unveiled a notable functional divergence between constitutively active mutants and receptor-activated Gαi1 to inhibit AC, and identified a previously unknown AC-interacting domain of Gαi subunits. These results collectively provide valuable insights on the mechanism of AC inhibition in the cellular environment.


Adenylyl Cyclases , GTP Phosphohydrolases , Adenylyl Cyclases/genetics , Adenylyl Cyclases/metabolism , GTP Phosphohydrolases/metabolism , Molecular Docking Simulation , GTP-Binding Proteins/genetics , GTP-Binding Proteins/metabolism , Carrier Proteins , GTP-Binding Protein alpha Subunits, Gi-Go/genetics , GTP-Binding Protein alpha Subunits, Gi-Go/metabolism
11.
Technol Cancer Res Treat ; 23: 15330338241241935, 2024.
Article En | MEDLINE | ID: mdl-38564315

Hepatocellular carcinoma (HCC), partly because of its complexity and high heterogeneity, has a poor prognosis and an extremely high mortality rate. In this study, mRNA sequencing expression profiles and relevant clinical data of HCC patients were gathered from different public databases. Kaplan-Meier survival curves as well as ROC curves validated that OLA1|CLEC3B was an independent predictor with better predictive capability of HCC prognosis compared to OLA1 and CLEC3B separately. Further, the cell transfection experiment verified that knockdown of OLA1 inhibited cell proliferation, facilitated apoptosis, and improved sensitivity of HCC cells to gemcitabine. In this study, the prognostic model of HCC composed of OLA1/CLEC3B genes was constructed and verified, and the prediction ability was favorable. A higher level of OLA1 along with a lower level of CEC3B is a sign of poor prognosis in HCC. We revealed a novel gene pair OLA1|CLEC3B overexpressed in HCC patients, which may serve as a promising independent predictor of HCC survival and an approach for innovative diagnostic and therapeutic strategies.


Carcinoma, Hepatocellular , Liver Neoplasms , Humans , Carcinoma, Hepatocellular/genetics , Prognosis , Liver Neoplasms/genetics , Apoptosis/genetics , Cell Proliferation/genetics , Adenosine Triphosphatases , GTP-Binding Proteins
12.
Actas Esp Psiquiatr ; 52(2): 83-98, 2024 Apr.
Article En | MEDLINE | ID: mdl-38622006

BACKGROUND: Vascular dementia (VaD) is a prevalent neurodegenerative disease characterized by cognitive impairment due to cerebrovascular factors, affecting a significant portion of the aging population and highlighting the critical need to understand specific targets and mechanisms for effective prevention and treatment strategies. We aimed to identify pathways and crucial genes involved in the progression of VaD through bioinformatics analysis and subsequently validate these findings. METHODS: We conducted differential expression analysis, Weighted Gene Co-expression Network Analysis (WGCNA), Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, and Protein-Protein Interaction (PPI) analysis. We utilized pheochromocytoma 12 (PC12) cells to create an in vitro oxygen-glucose deprivation (OGD) model. We investigated the impact of overexpression and interference of adrenoceptor alpha 1D (ADRA1D) on OGD PC12 cells using TdT-mediated dUTP nick-end labeling (TUNEL), reverse transcription-quantitative polymerase chain reaction (RT-qPCR), western blot (WB), and Fluo-3-pentaacetoxymethyl ester (Fluo-3 AM) analysis. RESULTS: We found 187 differentially expressed genes (DEGs) in the red module that were strongly associated with VaD and were primarily enriched in vasoconstriction, G protein-coupled amine receptor activity, and neuroactive ligand-receptor interaction, mitogen-activated protein kinase (MAPK) signaling pathway, and cell adhesion. Among these pathways, we identified ADRA1D as a gene shared by vasoconstriction, G protein-coupled amine receptor activity, and neuroactive ligand-receptor interaction. The TUNEL assay revealed a significant decrease in PC12 cell apoptosis with ADRA1D overexpression (p < 0.01) and a significant increase in apoptosis upon silencing ADRA1D (p < 0.01). RT-qPCR and WB analysis revealed elevated ADRA1D expression (p < 0.001) and decreased phospholipase C beta (PLCß) and inositol 1,4,5-trisphosphate receptor (IP3R) expression (p < 0.05) with ADRA1D overexpression. Moreover, the Fluo-3 AM assessment indicated significantly lower intracellular Ca2+ levels with ADRA1D overexpression (p < 0.001). Conversely, interference with ADRA1D yielded opposite results. CONCLUSION: Our study provides a new perspective on the pathogenic mechanisms of VaD and potential avenues for therapeutic intervention. The results highlight the role of ADRA1D in modulating cellular responses to OGD and VaD, suggesting its potential as a target for VaD treatment.


Aniline Compounds , Dementia, Vascular , Neurodegenerative Diseases , Xanthenes , Animals , Rats , Humans , Aged , Dementia, Vascular/genetics , Ligands , Amines , Signal Transduction/genetics , GTP-Binding Proteins
13.
Cells ; 13(7)2024 Mar 26.
Article En | MEDLINE | ID: mdl-38607016

Hereditary spastic paraplegias (HSPs) are a heterogeneous group of mono-genetic inherited neurological disorders, whose primary manifestation is the disruption of the pyramidal system, observed as a progressive impaired gait and leg spasticity in patients. Despite the large list of genes linked to this group, which exceeds 80 loci, the number of cellular functions which the gene products engage is relatively limited, among which endoplasmic reticulum (ER) morphogenesis appears central. Mutations in genes encoding ER-shaping proteins are the most common cause of HSP, highlighting the importance of correct ER organisation for long motor neuron survival. However, a major bottleneck in the study of ER morphology is the current lack of quantitative methods, with most studies to date reporting, instead, on qualitative changes. Here, we describe and apply a quantitative image-based screen to identify genetic modifiers of ER organisation using a mammalian cell culture system. An analysis reveals significant quantitative changes in tubular ER and dense sheet ER organisation caused by the siRNA-mediated knockdown of HSP-causing genes ATL1 and RTN2. This screen constitutes the first attempt to examine ER distribution in cells in an automated and high-content manner and to detect genes which impact ER organisation.


Nervous System Diseases , Spastic Paraplegia, Hereditary , Animals , Humans , Membrane Proteins/metabolism , Membrane Transport Proteins/genetics , GTP-Binding Proteins/metabolism , Spastic Paraplegia, Hereditary/genetics , Mammals/metabolism
14.
Biophys Chem ; 309: 107234, 2024 Jun.
Article En | MEDLINE | ID: mdl-38603989

Activation of heterotrimeric G-proteins (Gαßγ) downstream to receptor tyrosine kinases (RTKs) is a well-established crosstalk between the signaling pathways mediated by G-protein coupled receptors (GPCRs) and RTKs. While GPCR serves as a guanine exchange factor (GEF) in the canonical activation of Gα that facilitates the exchange of GDP for GTP, the mechanism through which RTK phosphorylations induce Gα activation remains unclear. Recent experimental studies revealed that the epidermal growth factor receptor (EGFR), a well-known RTK, phosphorylates the helical domain tyrosine residues Y154 and Y155 and accelerates the GDP release from the Gαi3, a subtype of Gα-protein. Using well-tempered metadynamics and extensive unbiased molecular dynamics simulations, we captured the GDP release event and identified the intermediates between bound and unbound states through Markov state models. In addition to weakened salt bridges at the domain interface, phosphorylations induced the unfolding of helix αF, which contributed to increased flexibility near the hinge region, facilitating a greater distance between domains in the phosphorylated Gαi3. Although the larger domain separation in the phosphorylated system provided an unobstructed path for the nucleotide, the accelerated release of GDP was attributed to increased fluctuations in several conserved regions like P-loop, switch 1, and switch 2. Overall, this study provides atomistic insights into the activation of G-proteins induced by RTK phosphorylations and identifies the specific structural motifs involved in the process. The knowledge gained from the study could establish a foundation for targeting non-canonical signaling pathways and developing therapeutic strategies against the ailments associated with dysregulated G-protein signaling.


Guanine Nucleotide Exchange Factors , Signal Transduction , Phosphorylation , Guanine Nucleotide Exchange Factors/chemistry , Guanine Nucleotide Exchange Factors/metabolism , GTP-Binding Proteins/metabolism , Tyrosine/metabolism
15.
Cell Rep ; 43(4): 114045, 2024 Apr 23.
Article En | MEDLINE | ID: mdl-38578826

Autoantibodies against the enzyme transglutaminase 2 (TG2) are characteristic of celiac disease (CeD), and TG2-specific immunoglobulin (Ig) A plasma cells are abundant in gut biopsies of patients. Here, we describe the corresponding population of autoreactive B cells in blood. Circulating TG2-specific IgA cells are present in untreated patients on a gluten-containing diet but not in controls. They are clonally related to TG2-specific small intestinal plasma cells, and they express gut-homing molecules, indicating that they are plasma cell precursors. Unlike other IgA-switched cells, the TG2-specific cells are negative for CD27, placing them in the double-negative (IgD-CD27-) category. They have a plasmablast or activated memory B cell phenotype, and they harbor fewer variable region mutations than other IgA cells. Based on their similarity to naive B cells, we propose that autoreactive IgA cells in CeD are generated mainly through chronic recruitment of naive B cells via an extrafollicular response involving gluten-specific CD4+ T cells.


B-Lymphocytes , Celiac Disease , GTP-Binding Proteins , Immunoglobulin A , Plasma Cells , Protein Glutamine gamma Glutamyltransferase 2 , Transglutaminases , Celiac Disease/immunology , Celiac Disease/pathology , Humans , Transglutaminases/immunology , Transglutaminases/metabolism , Immunoglobulin A/immunology , Immunoglobulin A/metabolism , Immunoglobulin A/blood , B-Lymphocytes/immunology , B-Lymphocytes/metabolism , Plasma Cells/immunology , Plasma Cells/metabolism , GTP-Binding Proteins/immunology , GTP-Binding Proteins/metabolism , Autoantibodies/immunology , Autoantibodies/blood , Adult , Male , Female , Middle Aged , Tumor Necrosis Factor Receptor Superfamily, Member 7/metabolism , Glutens/immunology
16.
Nutrients ; 16(7)2024 Apr 01.
Article En | MEDLINE | ID: mdl-38613059

High protein intake during infancy results in accelerated early weight gain and potentially later obesity. The aim of this follow-up study at 12 months was to evaluate if modified low-protein formulas fed during early infancy have long-term effects on growth and metabolism. In a double-blinded RCT, the ALFoNS study, 245 healthy-term infants received low-protein formulas with either alpha-lactalbumin-enriched whey (α-lac-EW; 1.75 g protein/100 kcal), casein glycomacropeptide-reduced whey (CGMP-RW; 1.76 g protein/100 kcal), or standard infant formula (SF; 2.2 g protein/100 kcal) between 2 and 6 months of age. Breastfed (BF) infants served as a reference. At 12 months, anthropometrics and dietary intake were assessed, and serum was analyzed for insulin, C-peptide, and insulin-like growth factor 1 (IGF-1). Weight gain between 6 and 12 months and BMI at 12 months were higher in the SF than in the BF infants (p = 0.019; p < 0.001, respectively), but were not significantly different between the low-protein formula groups and the BF group. S-insulin and C-peptide were higher in the SF than in the BF group (p < 0.001; p = 0.003, respectively), but more alike in the low-protein formula groups and the BF group. Serum IGF-1 at 12 months was similar in all study groups. Conclusion: Feeding modified low-protein formula during early infancy seems to reduce insulin resistance, resulting in more similar growth, serum insulin, and C-peptide concentrations to BF infants at 6-months post intervention. Feeding modified low-protein formula during early infancy results in more similar growth, serum insulin, and C-peptide concentrations to BF infants 6-months post intervention, probably due to reduced insulin resistance in the low-protein groups.


Infant Formula , Insulin Resistance , Humans , Infant , C-Peptide , Follow-Up Studies , GTP-Binding Proteins , Insulin , Insulin-Like Growth Factor I , Lactalbumin , Weight Gain , Prospective Studies
17.
Genes (Basel) ; 15(4)2024 Apr 08.
Article En | MEDLINE | ID: mdl-38674403

The aim of this study was to identify genetic markers in the HBB Cluster; HBS1L-MYB intergenic region; and BCL11A, KLF1, FOX3, and ZBTB7A genes associated with the heterogeneous phenotypes of Sickle Cell Anemia (SCA) using next-generation sequencing, as well as to assess their influence and prevalence in an Angolan population. Hematological, biochemical, and clinical data were considered to determine patients' severity phenotypes. Samples from 192 patients were sequenced, and 5,019,378 variants of high quality were registered. A catalog of candidate modifier genes that clustered in pathophysiological pathways important for SCA was generated, and candidate genes associated with increasing vaso-occlusive crises (VOC) and with lower fetal hemoglobin (HbF) were identified. These data support the polygenic view of the genetic architecture of SCA phenotypic variability. Two single nucleotide polymorphisms in the intronic region of 2q16.1, harboring the BCL11A gene, are genome-wide and significantly associated with decreasing HbF. A set of variants was identified to nominally be associated with increasing VOC and are potential genetic modifiers harboring phenotypic variation among patients. To the best of our knowledge, this is the first investigation of clinical variation in SCA in Angola using a well-customized and targeted sequencing approach.


Anemia, Sickle Cell , GTP-Binding Proteins , Phenotype , Polymorphism, Single Nucleotide , Humans , Anemia, Sickle Cell/genetics , Male , Child , Female , Genes, Modifier , Child, Preschool , Adolescent , Angola , Repressor Proteins/genetics , Fetal Hemoglobin/genetics , Kruppel-Like Transcription Factors/genetics
18.
Sci Rep ; 14(1): 9652, 2024 04 26.
Article En | MEDLINE | ID: mdl-38671143

Selective activation of individual subtypes of muscarinic receptors is a promising way to safely alleviate a wide range of pathological conditions in the central nervous system and the periphery as well. The flexible G-protein interface of muscarinic receptors allows them to interact with several G-proteins with various efficacy, potency, and kinetics. Agonists biased to the particular G-protein mediated pathway may result in selectivity among muscarinic subtypes and, due to the non-uniform expression of individual G-protein alpha subunits, possibly achieve tissue specificity. Here, we demonstrate that novel tetrahydropyridine-based agonists exert specific signalling profiles in coupling with individual G-protein α subunits. These signalling profiles profoundly differ from the reference agonist carbachol. Moreover, coupling with individual Gα induced by these novel agonists varies among subtypes of muscarinic receptors which may lead to subtype selectivity. Thus, the novel tetrahydropyridine-based agonist can contribute to the elucidation of the mechanism of pathway-specific activation of muscarinic receptors and serve as a starting point for the development of desired selective muscarinic agonists.


Muscarinic Agonists , Receptors, Muscarinic , Muscarinic Agonists/pharmacology , Receptors, Muscarinic/metabolism , Animals , Signal Transduction/drug effects , Humans , Pyridines/pharmacology , Carbachol/pharmacology , CHO Cells , Cricetulus , GTP-Binding Proteins/metabolism , GTP-Binding Protein alpha Subunits/metabolism , GTP-Binding Protein alpha Subunits/genetics
19.
Front Immunol ; 15: 1371706, 2024.
Article En | MEDLINE | ID: mdl-38650935

Pulmonary hypertension (PH) pathogenesis is driven by inflammatory and metabolic derangements as well as glycolytic reprogramming. Induction of both interleukin 6 (IL6) and transglutaminase 2 (TG2) expression participates in human and experimental cardiovascular diseases. However, little is known about the role of TG2 in these pathologic processes. The current study aimed to investigate the molecular interactions between TG2 and IL6 in mediation of tissue remodeling in PH. A lung-specific IL6 over-expressing transgenic mouse strain showed elevated right ventricular (RV) systolic pressure as well as increased wet and dry tissue weights and tissue fibrosis in both lungs and RVs compared to age-matched wild-type littermates. In addition, IL6 over-expression induced the glycolytic and fibrogenic markers, hypoxia-inducible factor 1α, pyruvate kinase M2 (PKM2), and TG2. Consistent with these findings, IL6 induced the expression of both glycolytic and pro-fibrogenic markers in cultured lung fibroblasts. IL6 also induced TG2 activation and the accumulation of TG2 in the extracellular matrix. Pharmacologic inhibition of the glycolytic enzyme, PKM2 significantly attenuated IL6-induced TG2 activity and fibrogenesis. Thus, we conclude that IL6-induced TG2 activity and cardiopulmonary remodeling associated with tissue fibrosis are under regulatory control of the glycolytic enzyme, PKM2.


Fibroblasts , GTP-Binding Proteins , Hypertension, Pulmonary , Interleukin-6 , Lung , Mice, Transgenic , Protein Glutamine gamma Glutamyltransferase 2 , Pyruvate Kinase , Transglutaminases , Animals , Humans , Mice , Disease Models, Animal , Fibroblasts/metabolism , Fibrosis , GTP-Binding Proteins/metabolism , GTP-Binding Proteins/genetics , Hypertension, Pulmonary/metabolism , Hypertension, Pulmonary/pathology , Hypertension, Pulmonary/etiology , Interleukin-6/metabolism , Lung/pathology , Lung/immunology , Lung/metabolism , Pulmonary Fibrosis/metabolism , Pulmonary Fibrosis/pathology , Pyruvate Kinase/metabolism , Pyruvate Kinase/genetics , Transglutaminases/metabolism , Transglutaminases/genetics
20.
Exp Lung Res ; 50(1): 106-117, 2024.
Article En | MEDLINE | ID: mdl-38642025

BACKGROUND: Pulmonary emphysema is a condition that causes damage to the lung tissue over time. GBP5, as part of the guanylate-binding protein family, is dysregulated in mouse pulmonary emphysema. However, the role of GBP5 in lung inflammation in ARDS remains unveiled. METHODS: To investigate whether GBP5 regulates lung inflammation and autophagy regulation, the study employed a mouse ARDS model and MLE-12 cell culture. Vector transfection was performed for the genetic manipulation of GBP5. Then, RT-qPCR, WB and IHC staining were conducted to assess its transcriptional and expression levels. Histological features of the lung tissue were observed through HE staining. Moreover, ELISA was conducted to evaluate the secretion of inflammatory cytokines, autophagy was assessed by immunofluorescent staining, and MPO activity was determined using a commercial kit. RESULTS: Our study revealed that GBP5 expression was altered in mouse ARDS and LPS-induced MLE-12 cell models. Moreover, the suppression of GBP5 reduced lung inflammation induced by LPS in mice. Conversely, overexpression of GBP5 diminished the inhibitory impact of LPS on ARDS during autophagy, leading to increased inflammation. In the cell line of MLE-12, GBP5 exacerbates LPS-induced inflammation by blocking autophagy. CONCLUSION: The study suggests that GBP5 facilitates lung inflammation and autophagy regulation. Thus, GBP5 could be a potential therapeutic approach for improving ARDS treatment outcomes, but further research is required to validate these findings.


Autophagy , GTP-Binding Proteins , Lung Injury , Pneumonia , Respiratory Distress Syndrome , Animals , Mice , Autophagy/drug effects , Inflammation/metabolism , Lipopolysaccharides , Lung/metabolism , Lung Injury/chemically induced , Lung Injury/metabolism , Pneumonia/metabolism , Pulmonary Emphysema , Respiratory Distress Syndrome/chemically induced , Respiratory Distress Syndrome/drug therapy , Respiratory Distress Syndrome/metabolism , GTP-Binding Proteins/antagonists & inhibitors , GTP-Binding Proteins/metabolism
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