scholarly journals Protein Kinase C Isozymes and Autophagy during Neurodegenerative Disease Progression

Cells ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 553 ◽  
Author(s):  
Humeyra Nur Kaleli ◽  
Ebru Ozer ◽  
Veysel Ogulcan Kaya ◽  
Ozlem Kutlu

Protein kinase C (PKC) isozymes are members of the Serine/Threonine kinase family regulating cellular events following activation of membrane bound phospholipids. The breakdown of the downstream signaling pathways of PKC relates to several disease pathogeneses particularly neurodegeneration. PKC isozymes play a critical role in cell death and survival mechanisms, as well as autophagy. Numerous studies have reported that neurodegenerative disease formation is caused by failure of the autophagy mechanism. This review outlines PKC signaling in autophagy and neurodegenerative disease development and introduces some polyphenols as effectors of PKC isozymes for disease therapy.

2000 ◽  
Vol 279 (4) ◽  
pp. C906-C914 ◽  
Author(s):  
Arshad Rahman ◽  
Khandaker N. Anwar ◽  
Asrar B. Malik

We addressed the role of protein kinase C (PKC) isozymes in mediating tumor necrosis factor-α (TNF-α)-induced oxidant generation in endothelial cells, a requirement for nuclear factor-κB (NF-κB) activation and intercellular adhesion molecule-1 (ICAM-1) gene transcription. Depletion of the conventional (c) and novel (n) PKC isozymes following 24 h exposure of human pulmonary artery endothelial (HPAE) cells with the phorbol ester, phorbol 12-myristate 13-acetate (500 nM), failed to prevent TNF-α-induced oxidant generation. In contrast, inhibition of PKC-ζ synthesis by the antisense oligonucleotide prevented the oxidant generation following the TNF-α stimulation. We observed that PKC-ζ also induced the TNF-α-induced NF-κB binding to the ICAM-1 promoter and the resultant ICAM-1 gene transcription. We showed that expression of the dominant negative mutant of PKC-ζ prevented the TNF-α-induced ICAM-1 promoter activity, whereas overexpression of the wild-type PKC-ζ augmented the response. These data imply a critical role for the PKC-ζ isozyme in regulating TNF-α-induced oxidant generation and in signaling the activation of NF-κB and ICAM-1 transcription in endothelial cells.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1748
Author(s):  
Takahito Kawano ◽  
Junichi Inokuchi ◽  
Masatoshi Eto ◽  
Masaharu Murata ◽  
Jeong-Hun Kang

Protein kinase C (PKC), a family of phospholipid-dependent serine/threonine kinase, is classed into three subfamilies based on their structural and activation characteristics: conventional or classic PKC isozymes (cPKCs; α, βI, βII, and γ), novel or non-classic PKC isozymes (nPKCs; δ, ε, η, and θ), and atypical PKC isozymes (aPKCs; ζ, ι, and λ). PKC inhibitors and activators are used to understand PKC-mediated intracellular signaling pathways and for the diagnosis and treatment of various PKC-associated diseases, such as cancers, neurological diseases, cardiovascular diseases, and infections. Many clinical trials of PKC inhibitors in cancers showed no significant clinical benefits, meaning that there is a limitation to design a cancer therapeutic strategy targeting PKC alone. This review will focus on the activators and inhibitors of PKC and their applications in clinical trials.


Author(s):  
Ghanshyam N Pandey ◽  
Anuradha Sharma ◽  
Hooriyah S Rizavi ◽  
Xinguo Ren

Abstract Background Several lines of evidence suggest the abnormalities of protein kinase C (PKC) signaling system in mood disorders and suicide based primarily on the studies of PKC and its isozymes in the platelets and postmortem brain of depressed and suicidal subjects. In this study we examined the role of PKC isozymes in depression and suicide. Methods We determined the protein and mRNA expression of various PKC isozymes in the prefrontal cortical region [Brodmann area 9 (BA9)] in 24 normal control (NC) subjects, 24 depressed suicide (DS) subjects and 12 depressed non-suicide (DNS) subjects. The levels of mRNA in the prefrontal cortex (PFC) were determined by qRT-PCR and the protein expression was determined by Western blotting. Results We observed a significant decrease in mRNA expression of PKCα, PKCβI, PKCδ and PKCε and decreased protein expression either in the membrane or the cytosol fraction of PKC isozymes - PKCα, PKCβI, PKCβII and PKCδ in DS and DNS subjects compared with NC subjects. Conclusions The current study provides detailed evidence of specific dysregulation of certain PKC isozymes in the postmortem brain of DS and DNS subjects and further supports earlier evidence for the role of PKC in the platelets and brain of adult and teenage depressed and suicidal population. This comprehensive study may lead to further knowledge of the involvement of PKC in the pathophysiology of depression and suicide.


2021 ◽  
Vol 22 (11) ◽  
pp. 5527
Author(s):  
Mohammad Mojtaba Sadeghi ◽  
Mohamed F. Salama ◽  
Yusuf A. Hannun

Driver-directed therapeutics have revolutionized cancer treatment, presenting similar or better efficacy compared to traditional chemotherapy and substantially improving quality of life. Despite significant advances, targeted therapy is greatly limited by resistance acquisition, which emerges in nearly all patients receiving treatment. As a result, identifying the molecular modulators of resistance is of great interest. Recent work has implicated protein kinase C (PKC) isozymes as mediators of drug resistance in non-small cell lung cancer (NSCLC). Importantly, previous findings on PKC have implicated this family of enzymes in both tumor-promotive and tumor-suppressive biology in various tissues. Here, we review the biological role of PKC isozymes in NSCLC through extensive analysis of cell-line-based studies to better understand the rationale for PKC inhibition. PKC isoforms α, ε, η, ι, ζ upregulation has been reported in lung cancer, and overexpression correlates with worse prognosis in NSCLC patients. Most importantly, PKC isozymes have been established as mediators of resistance to tyrosine kinase inhibitors in NSCLC. Unfortunately, however, PKC-directed therapeutics have yielded unsatisfactory results, likely due to a lack of specific evaluation for PKC. To achieve satisfactory results in clinical trials, predictive biomarkers of PKC activity must be established and screened for prior to patient enrollment. Furthermore, tandem inhibition of PKC and molecular drivers may be a potential therapeutic strategy to prevent the emergence of resistance in NSCLC.


Biomedicines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 381
Author(s):  
Noelia Geribaldi-Doldán ◽  
Irati Hervás-Corpión ◽  
Ricardo Gómez-Oliva ◽  
Samuel Domínguez-García ◽  
Félix A. Ruiz ◽  
...  

Glioblastoma (GBM) is the most frequent and aggressive primary brain tumor and is associated with a poor prognosis. Despite the use of combined treatment approaches, recurrence is almost inevitable and survival longer than 14 or 15 months after diagnosis is low. It is therefore necessary to identify new therapeutic targets to fight GBM progression and recurrence. Some publications have pointed out the role of glioma stem cells (GSCs) as the origin of GBM. These cells, with characteristics of neural stem cells (NSC) present in physiological neurogenic niches, have been proposed as being responsible for the high resistance of GBM to current treatments such as temozolomide (TMZ). The protein Kinase C (PKC) family members play an essential role in transducing signals related with cell cycle entrance, differentiation and apoptosis in NSC and participate in distinct signaling cascades that determine NSC and GSC dynamics. Thus, PKC could be a suitable druggable target to treat recurrent GBM. Clinical trials have tested the efficacy of PKCβ inhibitors, and preclinical studies have focused on other PKC isozymes. Here, we discuss the idea that other PKC isozymes may also be involved in GBM progression and that the development of a new generation of effective drugs should consider the balance between the activation of different PKC subtypes.


2019 ◽  
Author(s):  
Ann Rita Halvorsen ◽  
Mads Haugland Haugen ◽  
Åsa Kristina Öjlert ◽  
Marius Lund-Iversen ◽  
Lars Jørgensen ◽  
...  

Abstract Background Protein expression is deregulated in cancer, and the proteomic changes observed in lung cancer may be a consequence of mutations in essential genes. The purpose of this study was to identify protein expression associated with prognosis in lung cancers stratified by smoking status, molecular subtypes, and EGFR-, TP53- and KRAS-mutations. Methods We performed profiling of 295 cancer-relevant phosphorylated and non-phosphorylated proteins, using reverse phase protein arrays. Biopsies from 80 patients with operable lung adenocarcinomas were analyzed for protein expression and association with progression free survival (PFS) were studied. Results Spearman rank correlation analysis identified 56 proteins with significant association to PFS (p<0.05). High expression of protein kinase C (PKC)-α and the phosporylated state of PKC-α, PKC-β and PKC-δ, showed the strongest positive correlation to PFS, especially in the wild type samples. This was confirmed in gene expression data from 186 samples. Based on protein expression, unsupervised hierarchical clustering separated the samples into four subclusters enriched with the molecular subtypes TRU, PI or PP (p=0.0001). Subcluster 2 contained a smaller cluster (2a) enriched with samples of the subtype PP, low expression of the PKC isozymes, and associated with poor PFS (p=0.003) compared to the other samples. Subcluster 2a revealed increased expression of neuroendocrine markers, supporting the aggressive behavior. Low expression of the PKC isozymes in the subtype PP and a reduced relapse free survival was confirmed with the TCGA LUAD samples. Conclusion This study identified different proteins associated with PFS depending on molecular subtype, smoking- and mutational-status, with PKC-α, PKC-β and PKC-δ showing the strongest correlation. Cluster analysis detected a subgroup of samples enriched for samples of the PP subtype and poor PFS, which may benefit from a more aggressive treatment regimen.


Neuroreport ◽  
1998 ◽  
Vol 9 (11) ◽  
pp. 2669-2673 ◽  
Author(s):  
John H. Freeman ◽  
Andrew M. Scharenberg ◽  
James L. Olds ◽  
Bernard G. Schreurs

2000 ◽  
Vol 279 (3) ◽  
pp. L429-L438 ◽  
Author(s):  
Edward C. Dempsey ◽  
Alexandra C. Newton ◽  
Daria Mochly-Rosen ◽  
Alan P. Fields ◽  
Mary E. Reyland ◽  
...  

Individual protein kinase C (PKC) isozymes have been implicated in many cellular responses important in lung health and disease, including permeability, contraction, migration, hypertrophy, proliferation, apoptosis, and secretion. New ideas on mechanisms that regulate PKC activity, including the identification of a novel PKC kinase, 3-phosphoinositide-dependent kinase-1 (PDK-1), that regulates phosphorylation of PKC, have been advanced. The importance of targeted translocation of PKC and isozyme-specific binding proteins (like receptors for activated C-kinase and caveolins) is well established. Phosphorylation state and localization are now thought to be key determinants of isozyme activity and specificity. New concepts on the role of individual PKC isozymes in proliferation and apoptosis are emerging. Opposing roles for selected isozymes in the same cell system have been defined. Coupling to the Wnt signaling pathway has been described. Phenotypes for PKC knockout mice have recently been reported. More specific approaches for studying PKC isozymes and their role in cell responses have been developed. Strengths and weaknesses of different experimental strategies are reviewed. Future directions for investigation are identified.


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