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1.
BMJ Case Rep ; 17(5)2024 May 06.
Article in English | MEDLINE | ID: mdl-38719261

ABSTRACT

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.


Subject(s)
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
2.
Front Endocrinol (Lausanne) ; 15: 1392063, 2024.
Article in English | MEDLINE | ID: mdl-38715801

ABSTRACT

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.


Subject(s)
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
3.
Medicine (Baltimore) ; 103(18): e37847, 2024 May 03.
Article in English | MEDLINE | ID: mdl-38701254

ABSTRACT

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.


Subject(s)
Echocardiography , Mitochondrial Diseases , Mutation , Female , Humans , Echocardiography/methods , GTP-Binding Proteins/genetics , Mitochondrial Diseases/genetics , Mitochondrial Diseases/diagnostic imaging , Mitochondrial Diseases/diagnosis , Child
4.
J Genet ; 1032024.
Article in English | MEDLINE | ID: mdl-38736250

ABSTRACT

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


Subject(s)
Fetal Hemoglobin , Polymorphism, Single Nucleotide , Precursor Cell Lymphoblastic Leukemia-Lymphoma , Repressor Proteins , Humans , Fetal Hemoglobin/genetics , Female , Male , Child , Prognosis , Repressor Proteins/genetics , Child, Preschool , Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics , Infant , Nuclear Proteins/genetics , Proto-Oncogene Proteins c-myb/genetics , Carrier Proteins/genetics , Adolescent , Genotype , gamma-Globins/genetics , GTP-Binding Proteins
5.
J Mol Biol ; 436(10): 168569, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38604527

ABSTRACT

Transglutaminase 2 (TG2) performs many functions both under physiological and pathological conditions. In cancer, its expression is associated with aggressiveness, propensity to epithelial-mesenchymal transition, and metastasis. Since TG2 performs key functions both outside and inside the cell, using inhibitors with different membrane permeability we analyzed the changes in the transcriptome induced in two triple-negative cell lines (MDA-MB-436 and MDA-MB-231) with aggressive features. By characterizing pathways and gene networks, we were able to define the effects of TG2 inhibitors (AA9, membrane-permeable, and NCEG2, impermeable) in relation to the roles of the enzyme in the intra- and extracellular space within the context of breast cancer. The deregulated genes revealed p53 and integrin signaling to be the common pathways with some genes showing opposite changes in expression. In MDA-MB-436, AA9 induced apoptosis, modulated cadherin, Wnt, gastrin and cholecystokinin receptors (CCKR) mediated signaling, with RHOB and GNG2 playing significant roles, and affected the Warburg effect by decreasing glycolytic enzymes. In MDA-MB-231 cells, AA9 strongly impacted HIF-mediated hypoxia, including AKT and mTOR pathway. These effects suggest an anti-tumor activity by blocking intracellular TG2 functions. Conversely, the use of NCEG2 stimulated the expression of ATP synthase and proteins involved in DNA replication, indicating a potential promotion of cell proliferation through inhibition of extracellular TG2. To effectively utilize these molecules as an anti-tumor strategy, an appropriate delivery system should be evaluated to target specific functions and avoid adverse effects. Additionally, considering combinations with other pathway modulators is crucial.


Subject(s)
GTP-Binding Proteins , Protein Glutamine gamma Glutamyltransferase 2 , Transglutaminases , Humans , Transglutaminases/metabolism , Transglutaminases/genetics , GTP-Binding Proteins/metabolism , GTP-Binding Proteins/genetics , Cell Line, Tumor , Female , Gene Expression Regulation, Neoplastic/drug effects , Breast Neoplasms/genetics , Breast Neoplasms/drug therapy , Breast Neoplasms/pathology , Breast Neoplasms/metabolism , Transcriptome/drug effects , Gene Expression Profiling , Signal Transduction/drug effects , Apoptosis/drug effects , Cell Membrane Permeability/drug effects , Enzyme Inhibitors/pharmacology , Triple Negative Breast Neoplasms/genetics , Triple Negative Breast Neoplasms/drug therapy , Triple Negative Breast Neoplasms/pathology , Triple Negative Breast Neoplasms/metabolism
6.
Exp Lung Res ; 50(1): 106-117, 2024.
Article in English | MEDLINE | ID: mdl-38642025

ABSTRACT

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.


Subject(s)
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
7.
Cells ; 13(8)2024 Apr 11.
Article in English | MEDLINE | ID: mdl-38667282

ABSTRACT

Transglutaminase type 2 (TG2) is the most ubiquitously expressed member of the transglutaminase family. TG2 catalyzes the transamidation reaction leading to several protein post-translational modifications and it is also implicated in signal transduction thanks to its GTP binding/hydrolyzing activity. In the nervous system, TG2 regulates multiple physiological processes, such as development, neuronal cell death and differentiation, and synaptic plasticity. Given its different enzymatic activities, aberrant expression or activity of TG2 can contribute to tumorigenesis, including in peripheral and central nervous system tumors. Indeed, TG2 dysregulation has been reported in meningiomas, medulloblastomas, neuroblastomas, glioblastomas, and other adult-type diffuse gliomas. The aim of this review is to provide an overview of the biological and functional relevance of TG2 in the pathogenesis of nervous system tumors, highlighting its involvement in survival, tumor inflammation, differentiation, and in the resistance to standard therapies.


Subject(s)
GTP-Binding Proteins , Nervous System Neoplasms , Protein Glutamine gamma Glutamyltransferase 2 , Transglutaminases , Humans , Transglutaminases/metabolism , GTP-Binding Proteins/metabolism , Nervous System Neoplasms/pathology , Nervous System Neoplasms/enzymology , Nervous System Neoplasms/metabolism , Animals
8.
Vet Microbiol ; 293: 110089, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38678845

ABSTRACT

Brucellosis is a zoonotic disease that affects wild and domestic animals. It is caused by members of the bacterial genus Brucella. Guanylate-binding protein 1 (GBP1) is associated with microbial infections. However, the role of GBP1 during Brucella infection remains unclear. This investigation aimed to identify the association of GBP1 with brucellosis. Results showed that Brucella infection induced GBP1 upregulation in RAW 264.7 murine macrophages. Small interfering GBP1 targeting RNAs were utilized to explore how GBP1 regulates the survival of Brucella intracellularly. Results revealed that GBP1 knockdown promoted Brucella's survival ability, activated Nod-like receptor (NLR) containing a pyrin domain 3 (NLRP3) and absent in melanoma 2 (AIM2) inflammatory corpuscles, and induced pro-inflammatory cytokines IFN-γ and IL-1ß. Furthermore, Brucella stimulated the expression of GBP1 in bone marrow-derived macrophages (BMDMs) and mice. During the inhibition of GBP1 in BMDMs, the intracellular growth of Brucella increased. In comparison, GBP1 downregulation enhanced the accumulation of Brucella-induced reactive oxygen species (ROS) in macrophages. Overall, the data indicate a significant role of GBP1 in regulating brucellosis and suggest the function underlying its suppressive effect on the survival and growth of Brucella intracellularly.


Subject(s)
Brucellosis , GTP-Binding Proteins , Macrophages , Animals , Mice , GTP-Binding Proteins/genetics , GTP-Binding Proteins/metabolism , Macrophages/microbiology , Brucellosis/microbiology , RAW 264.7 Cells , Brucella/genetics , Reactive Oxygen Species/metabolism , Mice, Inbred C57BL
9.
Cells ; 13(7)2024 Mar 26.
Article in English | MEDLINE | ID: mdl-38607016

ABSTRACT

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.


Subject(s)
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
10.
Theranostics ; 14(6): 2329-2344, 2024.
Article in English | MEDLINE | ID: mdl-38646650

ABSTRACT

Diabetes, a severe metabolic disease characterized by chronic hypoglycemia, poses debilitating and life-threatening risks of microvascular and macrovascular complications, including blindness, kidney failure, heart attacks, and limb amputation. Addressing these complications is paramount, urging the development of interventions targeting diabetes-associated vascular dysfunctions. To effectively combat diabetes, a comprehensive understanding of the pathological mechanisms underlying complications and identification of precise therapeutic targets are imperative. Transglutaminase 2 (TGase2) is a multifunctional enzyme implicated in the pathogenesis of diverse diseases such as neurodegenerative disorders, fibrosis, and inflammatory conditions. TGase2 has recently emerged as a key player in both the pathogenesis and therapeutic intervention of diabetic complications. This review highlights TGase2 as a therapeutic target for diabetic complications and explores TGase2 inhibition as a promising therapeutic approach in their treatment.


Subject(s)
GTP-Binding Proteins , Protein Glutamine gamma Glutamyltransferase 2 , Transglutaminases , Humans , Transglutaminases/metabolism , Transglutaminases/antagonists & inhibitors , GTP-Binding Proteins/metabolism , Animals , Diabetic Angiopathies , Diabetes Mellitus , Diabetes Complications
11.
Front Immunol ; 15: 1371706, 2024.
Article in English | MEDLINE | ID: mdl-38650935

ABSTRACT

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.


Subject(s)
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
12.
Actas Esp Psiquiatr ; 52(2): 83-98, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38622006

ABSTRACT

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.


Subject(s)
Aniline Compounds , Dementia, Vascular , Neurodegenerative Diseases , Xanthenes , Animals , Rats , Humans , Aged , Dementia, Vascular/genetics , Ligands , Amines , Signal Transduction/genetics , GTP-Binding Proteins
13.
BMC Womens Health ; 24(1): 240, 2024 Apr 15.
Article in English | MEDLINE | ID: mdl-38622605

ABSTRACT

BACKGROUND: Human papillomavirus (HPV) infection is an important factor leading to cervical cell abnormalities. 90% of cervical cancers are closely associated with persistent infection of high-risk HPV, with the highest correlation with HPV16 and 18. Currently available vaccines and antivirals have limited effectiveness and coverage. Guanylate binding protein 1 (GBP1) was induced by interferon gamma and involved in many important cellular processes such as clearance of various microbial pathogens. However, whether GBP1 can inhibit human papillomavirus infection is unclear. RESULTS: In this study, we found that GBP1 can effectively degrade HPV18 E6, possibly through its GTPase activity or other pathways, and E6 protein degrades GBP1 through the ubiquitin-proteasome pathway to achieve immune escape. CONCLUSION: Therefore, GBP1 is an effector of IFN-γ anti-HPV activity. Our findings provided new insights into the treatment of HPV 18 infections.


Subject(s)
Papillomavirus Infections , Uterine Cervical Neoplasms , Female , Humans , GTP-Binding Proteins , Human papillomavirus 18 , Interferon-gamma/pharmacology
14.
Biophys Chem ; 309: 107234, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38603989

ABSTRACT

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.


Subject(s)
Guanine Nucleotide Exchange Factors , Signal Transduction , Phosphorylation , Guanine Nucleotide Exchange Factors/chemistry , Guanine Nucleotide Exchange Factors/metabolism , GTP-Binding Proteins/metabolism , Tyrosine/metabolism
15.
Technol Cancer Res Treat ; 23: 15330338241241935, 2024.
Article in English | MEDLINE | ID: mdl-38564315

ABSTRACT

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.


Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , Humans , Carcinoma, Hepatocellular/genetics , Prognosis , Liver Neoplasms/genetics , Apoptosis/genetics , Cell Proliferation/genetics , Adenosine Triphosphatases , GTP-Binding Proteins
16.
Nutrients ; 16(7)2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38613059

ABSTRACT

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.


Subject(s)
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.
Biomolecules ; 14(4)2024 Apr 19.
Article in English | MEDLINE | ID: mdl-38672511

ABSTRACT

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.


Subject(s)
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
18.
Sci Rep ; 14(1): 9652, 2024 04 26.
Article in English | MEDLINE | ID: mdl-38671143

ABSTRACT

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.


Subject(s)
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.
Genes (Basel) ; 15(4)2024 Apr 08.
Article in English | MEDLINE | ID: mdl-38674403

ABSTRACT

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.


Subject(s)
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
20.
Cell Rep ; 43(4): 114045, 2024 Apr 23.
Article in English | MEDLINE | ID: mdl-38578826

ABSTRACT

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.


Subject(s)
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
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