Role of myosin light chain and myosin light chain kinase in advanced glycation end product–induced endothelial hyperpermeability in vitro and in vivo

Abstract

We have previously reported that advanced glycation end products activated Rho-associated protein kinase and p38 mitogen-activated protein kinase, causing endothelial hyperpermeability. However, the mechanisms involved were not fully clarified. Here, we explored the role of myosin light chain kinase in advanced glycation end product-induced endothelial hyperpermeability. Myosin light chain phosphorylation significantly increased by advanced glycation end products in endothelial cells in a time-and dose-dependent manner, indicating that myosin light chain phosphorylation is involved in the advanced glycation end product pathway. Advanced glycation end products also induced myosin phosphatase-targeting subunit 1 phosphorylation, and small interfering RNA knockdown of the receptor for advanced glycation end products, or blocking myosin light chain kinase with its inhibitor, ML-7, or small interfering RNA abated advanced glycation end product-induced myosin light chain phosphorylation. Advanced glycation end product-induced F-actin rearrangement and endothelial hyperpermeability were also diminished by inhibition of receptor for advanced glycation end product or myosin light chain kinase signalling. Moreover, inhibiting myosin light chain kinase with ML-7 or blocking receptor for advanced glycation end product with its neutralizing antibody attenuated advanced glycation end product-induced microvascular hyperpermeability. Our findings suggest a novel role for myosin light chain and myosin light chain kinase in advanced glycation end product-induced endothelial hyperpermeability.

Brain‐derived and circulating vesicle profiles indicate neurovascular unit dysfunction in early Alzheimer’s disease

“…We also observed that in the absence of overt dementia pathology, both circulating and brainderived EVs from hypoperfused mice contain proteins already implicated in neuronal atrophy, neuroinflammation, neurotoxicity and maintenance of brain tissue integrity, including hippocalcin, neurofascin, NCAM1 and MOG. These findings indicate that hypoperfused mice exhibit key features of AD, including BBB hyperpermeability (33,54,71), BBB-associated neuroinflammation (16,37,73), associated amyloid-β and tau neurotoxicity (3,51) and impaired lipid metabolism (52). Our findings further indicate that brain EVs incorporate both mediators of neuroprotection and hallmarks of neuronal damage, consistent with the concept that these vesicles act as a "doubled-edged sword" in AD (6), and shed important new light on specific protein mediators that might contribute to this functional dichotomy.…”

Heat-Killed Lacticaseibacillus paracasei Repairs Lipopolysaccharide-Induced Intestinal Epithelial Barrier Damage via MLCK/MLC Pathway Activation

“…In addition, the nucleus receives the activated NF-B p65 subunit, which initiates MLCK transcription and increases MLCK protein production. Interestingly, LPS stimulation of intestinal epithelial cells simulates the production of inflammatory factors in vivo, further disrupting the intestinal epithelial barrier and activating the release of inflammatory factors [ 69 ]. Alternatively, the TJ protein expression is disrupted by MLCK protein activation, which disrupts TJ protein structure and function [ 70 ].…”

Studying the Geroprotective Properties of YAP/TAZ Signaling Inhibitors on Drosophila melanogaster Model

“…Aging is considered as a major risk factor for microvascular dysfunction and hyperpermeability [ 143 ]. ML7 has been reported to alleviate advanced glycation end products-induced microvascular hyperpermeability in vivo [ 144 ], demonstrating the potential to protect against aging. Drosophila suppression of actomyosin contractility via protein kinase A-mediated regulation of MLCK activity has shown to be required for blood–brain barrier integrity [ 145 ].…”