Disease-Defining Catalytically Inactive Protein Kinase C alpha Mutation is a Driver in Chordoid Glioma by Dominant-Negative Mechanism
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE279603 | GEO | 2026/07/21
REPOSITORIES: GEO
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Project description:BACKGROUND: The global prevalence of heart failure is increasing significantly, and the prognosis for patients with heart failure remains poor, highlighting the urgent need for novel therapeutic strategies. Protein kinase C alpha (PKCα) plays a central role in heart failure progression. Phosphorylation of PRKCA at T497 triggers a series of phosphorylation cascades, leading to its activation. Ablation of T497 phosphorylation leads to reduced protein stability and activity. However, there is no therapeutic strategy for heart failure targeting PKCα T497. METHODS: We employed CRISPR-Cas9 adenine base editing to ablate the phosphorylation site T497 of PKCα. We generated mice harboring a PKCα phosphoresistant T497A mutation in the germline and administered adeno-associated virus 9 (AAV9) harboring base editor of PrkcaT497A to postnatal wild-type (WT) mice to explore its clinical feasibility. To model for heart failure, mice were subjected to transverse aortic constriction (TAC). Cardiac function, hypertrophy, fibrosis, and transcriptional changes were evaluated by echocardiography, wheat germ agglutinin staining, Masson’s trichrome staining, and RNA sequencing, respectively. The editing efficiency of PrkcaT497A was assessed using Sanger sequencing and deep amplicon sequencing. Cellular Ca2+ homeostasis was analyzed using epifluorescence microscopy in Fura-2–loaded human induced pluripotent stem cells-derived cardiomyocytes (iPSC-CMs) carrying the PRKCAT497A mutation under chronic angiotensin II (AngII) stimulation. RESULTS: The T497A mutation in PKCα prevented subsequent phosphorylation and led to PKCα degradation. Four weeks after TAC surgery, WT mice showed dramatically impaired cardiac function, cardiac remodeling, and increased lung weight, whereas PKCα phosphoresistant mice were protected from these effects. PKCα phosphoresistant mice also showed protection against heart failure-related aberrant changes in cardiac gene expression, cardiac hypertrophy, and fibrosis. Likewise, mice administrated with AAV9-base editors exhibited similar cardioprotective effects against TAC-induced heart failure. In vitro, PKCα-edited iPSC-CMs were protected from AngII-induced impairments in contractility and Ca2+ transients observed in WT iPSC-CMs. CONCLUSIONS: The editing of PRKCAT497A through adenine base editing may potentially provide a promising therapeutic approach for human cardiac diseases.
2026-03-04 | GSE294246 | GEO
Project description:BACKGROUND: The global prevalence of heart failure is increasing significantly, and the prognosis for patients with heart failure remains poor, highlighting the urgent need for novel therapeutic strategies. Protein kinase C alpha (PKCα) plays a central role in heart failure progression. Phosphorylation of PRKCA at T497 triggers a series of phosphorylation cascades, leading to its activation. Ablation of T497 phosphorylation leads to reduced protein stability and activity. However, there is no therapeutic strategy for heart failure targeting PKCα T497. METHODS: We employed CRISPR-Cas9 adenine base editing to ablate the phosphorylation site T497 of PKCα. We generated mice harboring a PKCα phosphoresistant T497A mutation in the germline and administered adeno-associated virus 9 (AAV9) harboring base editor of PrkcaT497A to postnatal wild-type (WT) mice to explore its clinical feasibility. To model for heart failure, mice were subjected to transverse aortic constriction (TAC). Cardiac function, hypertrophy, fibrosis, and transcriptional changes were evaluated by echocardiography, wheat germ agglutinin staining, Masson’s trichrome staining, and RNA sequencing, respectively. The editing efficiency of PrkcaT497A was assessed using Sanger sequencing and deep amplicon sequencing. Cellular Ca2+ homeostasis was analyzed using epifluorescence microscopy in Fura-2–loaded human induced pluripotent stem cells-derived cardiomyocytes (iPSC-CMs) carrying the PRKCAT497A mutation under chronic angiotensin II (AngII) stimulation. RESULTS: The T497A mutation in PKCα prevented subsequent phosphorylation and led to PKCα degradation. Four weeks after TAC surgery, WT mice showed dramatically impaired cardiac function, cardiac remodeling, and increased lung weight, whereas PKCα phosphoresistant mice were protected from these effects. PKCα phosphoresistant mice also showed protection against heart failure-related aberrant changes in cardiac gene expression, cardiac hypertrophy, and fibrosis. Likewise, mice administrated with AAV9-base editors exhibited similar cardioprotective effects against TAC-induced heart failure. In vitro, PKCα-edited iPSC-CMs were protected from AngII-induced impairments in contractility and Ca2+ transients observed in WT iPSC-CMs. CONCLUSIONS: The editing of PRKCAT497A through adenine base editing may potentially provide a promising therapeutic approach for human cardiac diseases.
2026-03-04 | GSE308849 | GEO
Project description:Global gene expression analysis in PKCα-/- mouse skin reveals structural changes in the dermis and defective wound granulation tissue. The skin's mechanical integrity is maintained by an organised and robust dermal extracellular matrix (ECM). Resistance to mechanical disruption hinges primarily on homeostasis of the dermal collagen fibril architecture which is regulated, at least in part, by members of the small leucine-rich proteoglycan (SLRP) family. This array study presents data linking protein kinase C alpha (PKCα) to the regulated expression of multiple ECM components including SLRPs.
2016-01-20 | E-MTAB-3836 | biostudies-arrayexpress
Project description:The penetrant chordoid glioma PRKCA mutation is an oncogenic gain-of-function kinase inactivation eliciting early onset chondrosarcoma in mice
| PRJNA1122210 | ENA
Project description:A highly penetrant heterozygous mutation in PRKCA was found recently in chordoid glioma. To establish whether this mutant of PKCapha was a driver of tumour formation or maintenance in vivo, knock-in mice were generated. The constitutive, heterozygous expression of the Prkca D463H mutant in mice provoked the development of bilateral hindlimb chondrosarcomas and early neonatal mortality. The lack of activity of the D463H mutant was not the trigger of the phenotype as heterozygous knock-in of the related inactivating mutation D463N produced offspring indistinguishable from parental strains. Moreover, this surprising distinction between D463H and D463N mutations did not reflect a selective lack of dominance for the D463N mutation over the wild type (WT) allele since homozygous expression of this mutation was phenotypically WT. In cell culture, the D463H mutant expression, localisation and downregulation behaviours closely mimicked that of the WT, with the D463N mutant displaying some subtle differences. Biochemically, both the D463H and D463N mutants were shown to be inactive, although based on thermal shift assays the D463N mutant had reduced ATP affinity compared to WT or D463H proteins. Using induced transcriptional changes as a functional readout, altered mRNA expression indicates that the D463H acts as a dominant gain-of-function PKC mutant, despite a complete lack of intrinsic kinase activity; transcriptional changes induced by the D463N mutant were distinct from both the WT and D463H mutant. These findings suggest a model in which there is a non-catalytic effector function of PKCalpha which it is presumed operates through protein-protein interactions, as evidenced here by TurboID proximity labelling. The penetrant selection of the specific inactivating D463H mutation in chordoid glioma and the distinction with the D463N mutation indicates that this is conformationally sensitive. The properties characterised suggest this is driven by ATP binding and by inference, in this tissue context, the catalytic activity of this kinase acts as an autoregulatory negative feedback control.
2024-06-12 | GSE269531 | GEO
Project description:To determine the critical mediator of TRIB3-enhanced EGFR recycling, we examined the expression profile of genes that might regulate EGFR recycling by using mRNA microarrays. EGFR tyrosine kinase inhibitors (TKIs) confer first line therapy for patients with non-small-cell lung cancer (NSCLC). However, patients eventually develop disease progression, often driven by inevitable acquisition of EGFR TKI resistant mutations. Currently all EGFR TKIs repress NSCLC through inhibiting the kinase activity of EGFR signaling, highlighting the need for therapeutics with alternative mechanisms of action. Here we report that the elevated TRIB3 expression associates positively with EGFR stability and NSCLC progression. TRIB3 interacts with EGFR and recruits PKCα thereby enhances PKCα-induced T654 phosphorylation, which suppresses EGFR degradation and enhances membrane recycling, EGFR downstream signaling, and NSCLC stemness.
2020-06-09 | GSE103891 | GEO
Project description:Neutrophils contribute to the pathogenesis of chronic inflammatory skin diseases. Little is known about the source and identity of the signals mediating their recruitment in inflamed skin. We used the phorbol ester TPA and UVB, alone or in combination, to induce sterile inflammation in mouse skin and assess whether keratinocyte-derived signals impact neutrophil recruitment. A single TPA treatment results in a neutrophil influx in the dermis that peaks at 12h and resolves within 24h. A second TPA treatment or a UVB challenge, when applied at 24h but not 48h later, accelerates, amplifies, and prolongs neutrophil infiltration. This transient amplification response (TAR) is mediated by local signals in inflamed skin, can be recapitulated in ex vivo culture, and involves the K17-dependent sustainment of protein kinase Cα (PKCα) activity and release of neutrophil chemoattractants by stressed keratinocytes. We show that K17 binds RACK1, a scaffold essential for PKCα activity. Finally, analyses of RNAseq data reveal the presence of a transcriptomic signature consistent with TAR and PKCα activation in chronic inflammatory skin diseases. These findings uncover a novel, transient, and keratin-dependent mechanism that amplifies neutrophil recruitment to the skin under stress, with direct implications for inflammatory skin disorders.
2024-07-31 | GSE245384 | GEO
Project description:Early onset Parkinson’s Disease (onset <50 years) accounts for between 10-20 percent of all patients. While some of these cases are associated with specific mutations, the majority are sporadic where the cause is unknown. We generated induced pluripotent stem cells from sporadic early onset patients and differentiated them to dopamine neurons. At early stages in culture (30 days) we found significant elevations in soluble α-synuclein protein levels when compared to controls. This was associated with reductions in lysosomal membrane proteins such as LAMP1 and an increase in phosphorylated protein kinase C-α (p-PKCα). Testing activators of lysosomal function showed that specific phorbal esters reduced both α-synuclein and p-PKCα levels and increased LAMP1 expression. Interestingly, very low doses of the drug PEP005 were able to reduce α-synuclein levels without affecting p-PKCα. Similar effects of PEP005 on α-synuclein expression were seen following infusion into the mouse brain. Our data show that early onset sporadic Parkinson’s Disease can be accurately predicted using a ratio of α-synuclein and p-PKCα in dopamine neural cultures derived from patient iPSC’s and that specific phorbal esters can alter both biomarkers making these drugs promising candidates to treat Parkinson’s Disease.
2019-12-06 | PXD011326 | Pride
Project description:Leucine-rich-repeat-kinase 1 (LRRK1) and its homologue LRRK2 are multidomain kinases possessing an atypical ROC-CORA-CORB containing GTPase domain and phosphorylate distinct Rab proteins. LRRK1 loss of function mutations cause the bone disorder osteosclerotic metaphyseal dysplasia, whereas LRRK2 missense mutations that enhance kinase activity cause Parkinson’s disease. Previous work suggested that LRRK1 but not LRRK2, is activated via a Protein Kinase C (PKC)-dependent mechanism. Here we demonstrate that phosphorylation and activation of LRRK1 in HEK293 cells is blocked by PKC inhibitors including LXS-196 (Darovasertib), a compound that has entered human clinical trials. We show multiple PKC isoforms phosphorylate and activate recombinant LRRK1 in a manner reversed by phosphatase treatment. PKCα phosphorylates LRRK1 at cluster or conserved residues (Ser1064, Ser1074 and Thr1075) located within a region of the CORB domain that lies at the equivalent region of the LRRK2 DK helix that is reported to stabilize the kinase domain αC-helix in the active conformation. Thr1075 lies within an optimal PKC site phosphorylation motif and its mutation, blocked PKC mediated activation of LRRK1. A triple Glu mutation of Ser1064/Ser1074/Thr1075 to mimic phosphorylation, enhanced LRRK1 kinase activity ~3-fold. From analysis of available structures, we postulate that phosphorylation of Ser1064, Ser1074 and Thr1075 could activate LRRK1 promoting interaction of these residues with the C-helix on the kinase domain. This study provides fundamental insights into the mechanism controlling LRRK1 activity.
2022-09-02 | PXD034420 | Pride
Project description:A highly penetrant heterozygous mutation in PRKCA was found recently in chordoid glioma. To establish whether this mutant of PKC was a driver of tumour formation or maintenance in vivo, knock-in mice were generated. The constitutive, heterozygous expression of the Prkca D463H mutant in mice provoked the development of bilateral hindlimb chondrosarcomas and early neonatal mortality. The lack of activity of the D463H mutant was not the trigger of the phenotype as heterozygous knock-in of the related inactivating mutation D463N produced offspring indistinguishable from parental strains. Moreover, this surprising distinction between D463H and D463N mutations did not reflect a selective lack of dominance for the D463N mutation over the wild type (WT) allele since homozygous expression of this mutation was phenotypically WT. In cell culture, the D463H mutant expression, localisation and downregulation behaviours closely mimicked that of the WT, with the D463N mutant displaying some subtle differences. Biochemically, both the D463H and D463N mutants were shown to be inactive, although based on thermal shift assays the D463N mutant had reduced ATP affinity compared to WT or D463H proteins. Using induced transcriptional changes as a functional readout, altered mRNA expression indicates that the D463H acts as a dominant gain-of-function PKC mutant, despite a complete lack of intrinsic kinase activity; transcriptional changes induced by the D463N mutant were distinct from both the WT and D463H mutant. These findings suggest a model in which there is a non-catalytic effector function of PKC which it is presumed operates through protein-protein interactions, as evidenced here by TurboID proximity labelling. The penetrant selection of the specific inactivating D463H mutation in chordoid glioma and the distinction with the D463N mutation indicates that this is conformationally sensitive. The properties characterised suggest this is driven by ATP binding and by inference, in this tissue context, the catalytic activity of this kinase acts as an autoregulatory negative feedback control.
2025-05-29 | PXD049959 | Pride