bims-sikglu 2024-03-10 papers

Cell Commun Signal. 2024 Mar 04. 22(1): 159

Role of the NF-kB signalling pathway in heterotopic ossification: biological and therapeutic significance.

Fangzhou Liu, Yike Zhao, Yiran Pei, Fengyu Lian, Hui Lin.

Heterotopic ossification (HO) is a pathological process in which ectopic bone develops in soft tissues within the skeletal system. Endochondral ossification can be divided into the following types of acquired and inherited ossification: traumatic HO (tHO) and fibrodysplasia ossificans progressiva (FOP). Nuclear transcription factor kappa B (NF-κB) signalling is essential during HO. NF-κB signalling can drive initial inflammation through interactions with the NOD-like receptor protein 3 (NLRP3) inflammasome, Sirtuin 1 (SIRT1) and AMP-activated protein kinase (AMPK). In the chondrogenesis stage, NF-κB signalling can promote chondrogenesis through interactions with mechanistic target of rapamycin (mTOR), phosphatidylinositol-3-kinase (PI3K)/AKT (protein kinase B, PKB) and other molecules, including R-spondin 2 (Rspo2) and SRY-box 9 (Sox9). NF-κB expression can modulate osteoblast differentiation by upregulating secreted protein acidic and rich in cysteine (SPARC) and interacting with mTOR signalling, bone morphogenetic protein (BMP) signalling or integrin-mediated signalling under stretch stimulation in the final osteogenic stage. In FOP, mutated ACVR1-induced NF-κB signalling exacerbates inflammation in macrophages and can promote chondrogenesis and osteogenesis in mesenchymal stem cells (MSCs) through interactions with smad signalling and mTOR signalling. This review summarizes the molecular mechanism of NF-κB signalling during HO and highlights potential therapeutics for treating HO.

Keywords: Heterotopic ossification; Molecular mechanism; NF-κb signalling; Treatment

DOI: https://doi.org/10.1186/s12964-024-01533-w

Curr Protoc. 2024 Mar;4(3): e998

Steady State and Time-Dependent Fluorescent Peptide Assays for Protein Kinases.

Rae M Sammons, Ashwini K Devkota, Tamer S Kaoud, Mangalika Warthaka, Eun Jeong Cho, Kevin N Dalby.

Protein kinases catalyze the phosphorylation of proteins most commonly on Ser, Thr, and Tyr residues and regulate many cellular events in eukaryotic cells, such as cell cycle progression, transcription, metabolism, and apoptosis. Protein kinases each have a conserved ATP-binding site and one or more substrate-binding site(s) that exhibit recognition features for different protein substrates. By bringing ATP and a substrate into proximity, each protein kinase can transfer the γ phosphate of the ATP molecule to a hydroxyl group of the target residue on the substrate. In such a way, signaling pathways downstream from the substrate can be regulated based on the phosphorylated versus dephosphorylated status of the substrate. Although there are a number of ways to assay the activity of protein kinases, most of them are technically cumbersome and/or are indirect or based on quenched reactions. This protocol describes an assay employing a fluorescent peptide substrate to detect phosphorylation by protein kinases in real time. The assay is based on the principle that the phosphorylation of the peptide substrate leads to an increase in the fluorescence emission intensity of an appended fluorophore. We extend the application of this assay to an example of how to assess time-dependent covalent inhibition of kinases as well. © 2024 Wiley Periodicals LLC. Basic Protocol 1: Measuring protein kinase activity using fluorescent peptides Alternate Protocol: Measuring protein kinase activity using a fluorescence plate reader Support Protocol: Labeling peptides with sox fluorophore Basic Protocol 2: Measuring time-dependent ATP-competitive inhibition of protein kinases using fluorescent peptides.

Keywords: covalent kinase inhibition; fluorescent peptides; kinases; peptide assays

DOI: https://doi.org/10.1002/cpz1.998

Front Mol Biosci. 2024 ;11 1354682

Kinase signalling adaptation supports dysfunctional mitochondria in disease.

George L Skalka, Mina Tsakovska, Daniel J Murphy.

Mitochondria form a critical control nexus which are essential for maintaining correct tissue homeostasis. An increasing number of studies have identified dysregulation of mitochondria as a driver in cancer. However, which pathways support and promote this adapted mitochondrial function? A key hallmark of cancer is perturbation of kinase signalling pathways. These pathways include mitogen activated protein kinases (MAPK), lipid secondary messenger networks, cyclic-AMP-activated (cAMP)/AMP-activated kinases (AMPK), and Ca2+/calmodulin-dependent protein kinase (CaMK) networks. These signalling pathways have multiple substrates which support initiation and persistence of cancer. Many of these are involved in the regulation of mitochondrial morphology, mitochondrial apoptosis, mitochondrial calcium homeostasis, mitochondrial associated membranes (MAMs), and retrograde ROS signalling. This review will aim to both explore how kinase signalling integrates with these critical mitochondrial pathways and highlight how these systems can be usurped to support the development of disease. In addition, we will identify areas which require further investigation to fully understand the complexities of these regulatory interactions. Overall, this review will emphasize how studying the interaction between kinase signalling and mitochondria improves our understanding of mitochondrial homeostasis and can yield novel therapeutic targets to treat disease.

Keywords: apoptosis; disease adaptation; kinase; mitochondria; mitochondrial associated endoplasmic reticulum membranes (MAMs); mitochondrial morphology; reactive oxygen species (ROS)

DOI: https://doi.org/10.3389/fmolb.2024.1354682