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Frontiers in Endocrinology 2024Gonadotropin-releasing hormone (GnRH) is a key stimulator for gonadotropin secretion in the pituitary and its pivotal role in reproduction is well conserved in...
Differential involvement of cAMP/PKA-, PLC/PKC- and Ca/calmodulin-dependent pathways in GnRH-induced prolactin secretion and gene expression in grass carp pituitary cells.
Gonadotropin-releasing hormone (GnRH) is a key stimulator for gonadotropin secretion in the pituitary and its pivotal role in reproduction is well conserved in vertebrates. In fish models, GnRH can also induce prolactin (PRL) release, but little is known for the corresponding effect on PRL gene expression as well as the post-receptor signalling involved. Using grass carp as a model, the functional role of GnRH and its underlying signal transduction for PRL regulation were examined at the pituitary level. Using laser capture microdissection coupled with RT-PCR, GnRH receptor expression could be located in carp lactotrophs. In primary cell culture prepared from grass carp pituitaries, the native forms of GnRH, GnRH2 and GnRH3, as well as the GnRH agonist [D-Arg, Pro, NEt]-sGnRH were all effective in elevating PRL secretion, PRL mRNA level, PRL cell content and total production. In pituitary cells prepared from the rostral pars distalis, the region in the carp pituitary enriched with lactotrophs, GnRH not only increased cAMP synthesis with parallel CREB phosphorylation and nuclear translocation but also induced a rapid rise in cytosolic Ca by Ca influx via L-type voltage-sensitive Ca channel (VSCC) with subsequent CaM expression and NFAT dephosphorylation. In carp pituitary cells prepared from whole pituitaries, GnRH-induced PRL secretion was reduced/negated by inhibiting cAMP/PKA, PLC/PKC and Ca/CaM/CaMK-II pathways but not the signalling events via IP and CaN/NFAT. The corresponding effect on PRL mRNA expression, however, was blocked by inhibiting cAMP/PKA/CREB/CBP and Ca/CaM/CaN/NFAT signalling but not PLC/IP/PKC pathway. At the pituitary cell level, activation of cAMP/PKA pathway could also induce CaM expression and Ca influx via VSCC with parallel rises in PRL release and gene expression in a Ca/CaM-dependent manner. These findings, as a whole, suggest that the cAMP/PKA-, PLC/PKC- and Ca/CaM-dependent cascades are differentially involved in GnRH-induced PRL secretion and PRL transcript expression in carp lactotrophs. During the process, a functional crosstalk between the cAMP/PKA- and Ca/CaM-dependent pathways may occur with PRL release linked with CaMK-II and PKC activation and PRL gene transcription caused by nuclear action of CREB/CBP and CaN/NFAT signalling.
Topics: Animals; Carps; Gonadotropin-Releasing Hormone; Prolactin; Pituitary Gland; Protein Kinase C; Cyclic AMP-Dependent Protein Kinases; Calcium; Type C Phospholipases; Cyclic AMP; Signal Transduction; Calmodulin; Cells, Cultured; Gene Expression
PubMed: 38894746
DOI: 10.3389/fendo.2024.1399274 -
International Journal of Molecular... Jun 2024Although glaucoma is a leading cause of irreversible blindness worldwide, its pathogenesis is incompletely understood, and intraocular pressure (IOP) is the only...
Although glaucoma is a leading cause of irreversible blindness worldwide, its pathogenesis is incompletely understood, and intraocular pressure (IOP) is the only modifiable risk factor to target the disease. Several associations between the gut microbiome and glaucoma, including the IOP, have been suggested. There is growing evidence that interactions between microbes on the ocular surface, termed the ocular surface microbiome (OSM), and tear proteins, collectively called the tear proteome, may also play a role in ocular diseases such as glaucoma. This study aimed to find characteristic features of the OSM and tear proteins in patients with glaucoma. The whole-metagenome shotgun sequencing of 32 conjunctival swabs identified Actinobacteria, Firmicutes, and Proteobacteria as the dominant phyla in the cohort. The species was only found in healthy controls, and their conjunctival microbiomes may be enriched in genes of the phospholipase pathway compared to glaucoma patients. Despite these minor differences in the OSM, patients showed an enrichment of many tear proteins associated with the immune system compared to controls. In contrast to the OSM, this emphasizes the role of the proteome, with a potential involvement of immunological processes in glaucoma. These findings may contribute to the design of new therapeutic approaches targeting glaucoma and other associated diseases.
Topics: Humans; Glaucoma; Proteome; Male; Female; Microbiota; Tears; Middle Aged; Eye Proteins; Aged; Conjunctiva; Metagenome; Adult
PubMed: 38892444
DOI: 10.3390/ijms25116257 -
International Journal of Molecular... May 2024Following the discovery of podocyte phospholipase A2 receptor and thrombospondin type-1 domain-containing 7A, various potential target antigens for membranous... (Review)
Review
Following the discovery of podocyte phospholipase A2 receptor and thrombospondin type-1 domain-containing 7A, various potential target antigens for membranous nephropathy (MN) have been reported one after another. MN target antigens have now been identified in a significant proportion of patients, and a new classification framework classifies patients with MN based on the detected antigen and associated disease phenotype. A serology-based approach that does not require a histological diagnosis for patients suspected of having MN has also been proposed. However, there have been cases in which dual positivity for MN antigens and/or corresponding antibodies has been shown. Importantly, some of them showed a transition of the affected patient's immune responses to MN antigens, suggesting that serological diagnosis changes depending on the timing of the analysis. In this review, we provide detailed information on these cases and present an overview of our recent understanding of their putative mechanisms involved in these cases. Greater awareness is required to adequately recognize and develop appropriate therapeutic strategies for this condition.
Topics: Glomerulonephritis, Membranous; Humans; Receptors, Phospholipase A2; Autoantigens; Prevalence; Podocytes; Autoantibodies; Thrombospondins
PubMed: 38892120
DOI: 10.3390/ijms25115931 -
International Journal of Molecular... May 2024Retinitis pigmentosa (RP) is an inherited retinal dystrophy caused by the loss of photoreceptors and retinal pigment epithelial atrophy, leading to severe visual...
Retinitis pigmentosa (RP) is an inherited retinal dystrophy caused by the loss of photoreceptors and retinal pigment epithelial atrophy, leading to severe visual impairment or blindness. RP can be classified as nonsyndromic or syndromic with complex clinical phenotypes. Three unrelated Polish probands affected with retinitis pigmentosa coexisting with cerebellar ataxia were recruited for this study. Clinical heterogeneity and delayed appearance of typical disease symptoms significantly prolonged the patients' diagnostic process. Therefore, many clinical and genetic tests have been performed in the past. Here, we provide detailed clinical and genetic analysis results of the patients. Whole-exome sequencing (WES) and targeted NGS analysis allow the identification of four novel and two previously reported variants in the following genes: , , and The use of next-generation sequencing (NGS) methods finally allowed for confirmation of the clinical diagnosis. Ultra-rare diseases such as PHARC, PCARP, and Oliver-McFarlane syndromes were diagnosed in patients, respectively. Our findings confirmed the importance of the application of next-generation sequencing methods, especially in ultra-rare genetic disorders with overlapping features.
Topics: Humans; Retinitis Pigmentosa; Male; Female; Exome Sequencing; Pedigree; High-Throughput Nucleotide Sequencing; Adult; Cerebellar Ataxia; Membrane Transport Proteins; Monoacylglycerol Lipases; Mutation; Ataxia; Phenotype; Acyltransferases; Cataract; Phospholipases; Polyneuropathies
PubMed: 38891946
DOI: 10.3390/ijms25115759 -
Plants (Basel, Switzerland) May 2024In plant models such as , phosphatidic acid (PA), a key molecule of lipid signaling, was shown not only to be involved in stress responses, but also in plant development...
In plant models such as , phosphatidic acid (PA), a key molecule of lipid signaling, was shown not only to be involved in stress responses, but also in plant development and nutrition. In this article, we highlight lipid signaling existing in crop species. Based on open access databases, we update the list of sequences encoding phospholipases D, phosphoinositide-dependent phospholipases C, and diacylglycerol-kinases, enzymes that lead to the production of PA. We show that structural features of these enzymes from model plants are conserved in equivalent proteins from selected crop species. We then present an in-depth discussion of the structural characteristics of these proteins before focusing on PA binding proteins. For the purpose of this article, we consider RESPIRATORY BURST OXIDASE HOMOLOGUEs (RBOHs), the most documented PA target proteins. Finally, we present pioneering experiments that show, by different approaches such as monitoring of gene expression, use of pharmacological agents, ectopic over-expression of genes, and the creation of silenced mutants, that lipid signaling plays major roles in crop species. Finally, we present major open questions that require attention since we have only a perception of the peak of the iceberg when it comes to the exciting field of phospholipid signaling in plants.
PubMed: 38891340
DOI: 10.3390/plants13111532 -
Cells Jun 2024Crohn's disease is a chronic, debilitating, inflammatory bowel disease. Here, we report a critical role of phospholipase C-β3 (PLC-β3) in intestinal homeostasis. In...
Crohn's disease is a chronic, debilitating, inflammatory bowel disease. Here, we report a critical role of phospholipase C-β3 (PLC-β3) in intestinal homeostasis. In PLC-β3-deficient mice, exposure to oral dextran sodium sulfate induced lethality and severe inflammation in the small intestine. The lethality was due to PLC-β3 deficiency in multiple non-hematopoietic cell types. PLC-β3 deficiency resulted in reduced Wnt/β-catenin signaling, which is essential for homeostasis and the regeneration of the intestinal epithelium. PLC-β3 regulated the Wnt/β-catenin pathway in small intestinal epithelial cells (IECs) at transcriptional, epigenetic, and, potentially, protein-protein interaction levels. PLC-β3-deficient IECs were unable to respond to stimulation by R-spondin 1, an enhancer of Wnt/β-catenin signaling. Reduced expression of PLC-β3 and its signature genes was found in biopsies of patients with ileal Crohn's disease. PLC-β regulation of Wnt signaling was evolutionally conserved in . Our data indicate that a reduction in PLC-β3-mediated Wnt/β-catenin signaling contributes to the pathogenesis of ileal Crohn's disease.
Topics: Crohn Disease; Wnt Signaling Pathway; Phospholipase C beta; Animals; Humans; Mice; beta Catenin; Intestinal Mucosa; Ileum; Mice, Inbred C57BL; Mice, Knockout
PubMed: 38891118
DOI: 10.3390/cells13110986 -
Frontiers in Immunology 2024The impact of chronic hepatic infection on antigen non-specific immune cells in circulation remains poorly understood. We reported lasting global hyperfunction of...
Lasting differential gene expression of circulating CD8 T cells in chronic HCV infection with cirrhosis identifies a role for Hedgehog signaling in cellular hyperfunction.
BACKGROUND
The impact of chronic hepatic infection on antigen non-specific immune cells in circulation remains poorly understood. We reported lasting global hyperfunction of peripheral CD8 T cells in HCV-infected individuals with cirrhosis. Whether gene expression patterns in bulk CD8 T cells are associated with the severity of liver fibrosis in HCV infection is not known.
METHODS
RNA sequencing of blood CD8 T cells from treatment naïve, HCV-infected individuals with minimal (Metavir F0-1 ≤ 7.0 kPa) or advanced fibrosis or cirrhosis (F4 ≥ 12.5 kPa), before and after direct-acting antiviral therapy, was performed. CD8 T cell function was assessed by flow cytometry.
RESULTS
In CD8 T cells from pre-DAA patients with advanced compared to minimal fibrosis, Gene Ontology analysis and Gene Set Enrichment Analysis identified differential gene expression related to cellular function and metabolism, including upregulated Hedgehog (Hh) signaling, IFN-α, -γ, TGF-β response genes, apoptosis, apical surface pathways, phospholipase signaling, phosphatidyl-choline/inositol activity, and second-messenger-mediated signaling. In contrast, genes in pathways associated with nuclear processes, RNA transport, cytoskeletal dynamics, cMyc/E2F regulation, oxidative phosphorylation, and mTOR signaling, were reduced. Hh signaling pathway was the top featured gene set upregulated in cirrhotics, wherein hallmark genes and ranked highly. Inhibition of Smo-dependent Hh signaling ablated the expression of IFN-γ and perforin in stimulated CD8 T cells from chronic HCV-infected patients with advanced compared to minimal fibrosis. CD8 T cell gene expression profiles post-DAA remained clustered with pre-DAA profiles and disparately between advanced and minimal fibrosis, suggesting a persistent perturbation of gene expression long after viral clearance.
CONCLUSIONS
This analysis of bulk CD8 T cell gene expression in chronic HCV infection suggests considerable reprogramming of the CD8 T cell pool in the cirrhotic state. Increased Hh signaling in cirrhosis may contribute to generalized CD8 T cell hyperfunction observed in chronic HCV infection. Understanding the lasting nature of immune cell dysfunction may help mitigate remaining clinical challenges after HCV clearance and more generally, improve long term outcomes for individuals with severe liver disease.
Topics: Humans; CD8-Positive T-Lymphocytes; Hepatitis C, Chronic; Hedgehog Proteins; Liver Cirrhosis; Signal Transduction; Male; Middle Aged; Female; Hepacivirus; Adult; Aged; Gene Expression Profiling; Transcriptome; Gene Expression Regulation
PubMed: 38887299
DOI: 10.3389/fimmu.2024.1375485 -
Neural Regeneration Research Mar 2025Tropomyosin receptor kinase B (TrkB) signaling plays a pivotal role in dendritic growth and dendritic spine formation to promote learning and memory. The...
Tropomyosin receptor kinase B (TrkB) signaling plays a pivotal role in dendritic growth and dendritic spine formation to promote learning and memory. The activity-dependent release of brain-derived neurotrophic factor at synapses binds to pre- or postsynaptic TrkB resulting in the strengthening of synapses, reflected by long-term potentiation. Postsynaptically, the association of postsynaptic density protein-95 with TrkB enhances phospholipase Cγ-Ca2+/calmodulin-dependent protein kinase II and phosphatidylinositol 3-kinase-mechanistic target of rapamycin signaling required for long-term potentiation. In this review, we discuss TrkB-postsynaptic density protein-95 coupling as a promising strategy to magnify brain-derived neurotrophic factor signaling towards the development of novel therapeutics for specific neurological disorders. A reduction of TrkB signaling has been observed in neurodegenerative disorders, such as Alzheimer's disease and Huntington's disease, and enhancement of postsynaptic density protein-95 association with TrkB signaling could mitigate the observed deficiency of neuronal connectivity in schizophrenia and depression. Treatment with brain-derived neurotrophic factor is problematic, due to poor pharmacokinetics, low brain penetration, and side effects resulting from activation of the p75 neurotrophin receptor or the truncated TrkB.T1 isoform. Although TrkB agonists and antibodies that activate TrkB are being intensively investigated, they cannot distinguish the multiple human TrkB splicing isoforms or cell type-specific functions. Targeting TrkB-postsynaptic density protein-95 coupling provides an alternative approach to specifically boost TrkB signaling at localized synaptic sites versus global stimulation that risks many adverse side effects.
PubMed: 38886937
DOI: 10.4103/NRR.NRR-D-23-02000 -
Journal of Genetics and Genomics = Yi... Jun 2024Phospholipase D (PLD) lipid-signaling enzyme superfamily has been widely implicated in various human malignancies, but its role and underlying mechanism remain unclear...
Phospholipase D (PLD) lipid-signaling enzyme superfamily has been widely implicated in various human malignancies, but its role and underlying mechanism remain unclear in nasopharyngeal carcinoma (NPC). Here, we analyze the expressions of 6 PLD family members between 87 NPC and 10 control samples through transcriptome analysis. Our findings reveal a notable upregulation of PLD1 in both NPC tumors and cell lines, correlating with worse disease-free and overall survival in NPC patients. Functional assays further elucidate PLD1's oncogenic role, demonstrating its pivotal promotion of critical tumorigenic processes such as cell proliferation and migration in vitro, as well as tumor growth in vivo. Notably, our study uncovers a positive feedback loop between PLD1 and the NF-κB signaling pathway to render NPC progression. Specifically, PLD1 enhances NF-κB activity by facilitating the phosphorylation and nuclear translocation of RELA (p65), which in turn binds to the promoter of PLD1, augmenting its expression. Moreover, RELA overexpression significantly rescues the inhibitory effects in PLD1-depleted NPC cells. Importantly, the application of the PLD1 inhibitor, VU0155069, significantly inhibits NPC tumorigenesis in a patient-derived xenograft model. Together, our findings identify PLD1/NF-κB signaling as a positive feedback loop with promising therapeutic and prognostic potential in NPC.
PubMed: 38885836
DOI: 10.1016/j.jgg.2024.06.004 -
Research Square Jun 2024Parvovirus B19 (B19V) is a human pathogen that is the causative agent of several diseases in infants and adults. Due to a lack of antivirals against this virus,...
Parvovirus B19 (B19V) is a human pathogen that is the causative agent of several diseases in infants and adults. Due to a lack of antivirals against this virus, treatment options are limited. The minor capsid protein of B19V has a unique N terminus, named VP1u, which is essential for infection. The VP1u encodes a receptor binding domain (RBD), necessary for host cell entry, and a phospholipase A2 (PLA) domain, crucial for endosomal escape during cellular trafficking. Both domains are indispensable for infection, making the RBD a plausible drug target for inhibitors against B19V, as it is located on the exterior surface of the virus. To date, no experimental structural information has been available for the VP1u component for any Parvovirus. Here we report the backbone NMR resonance assignments for the RBD of B19V and demonstrate it forms a stable structure. The backbone chemical shifts are in good agreement with a structure predicted by AlphaFold, validating that the RBD contains three helices connected by tight turns. This RBD construct can now be used for further NMR studies, including assignment of full-length VP1u, determination of protein-protein interaction interfaces, and development of B19 antivirals specific to the RBD domain. BMRB submission code: 52440.
PubMed: 38883784
DOI: 10.21203/rs.3.rs-4441481/v1