Discovery of novel heterocyclic derivatives as potential glycogen phosphorylase inhibitors with a cardioprotective effect

et al. 2023

Self Cite

Brain-type glycogen phosphorylase (PYGB) inhibitors are recognized as prospective drugs for treating ischemic brain injury. We previously reported compound 1 as a novel glycogen phosphorylase inhibitor with brain-protective properties. In this study, we validated whether PYGB could be used as the therapeutic target for hypoxic-ischemic diseases and investigated whether compound 1 exerts a protective effect against astrocyte hypoxia/reoxygenation (H/R) injury by targeting PYGB. A gene-silencing strategy was initially applied to downregulate PYGB proteins in mouse astrocytes, which was followed by a series of cellular experiments with compound 1. Next, we compared relevant indicators that could prove the protective effect of compound 1 on brain injury, finding that after PYGB knockdown, compound 1 could not obviously alleviate astrocytes H/R injury, as evidenced by cell viability, which was not significantly improved, and lactate dehydrogenase (LDH) leakage rate, intracellular glucose content, and post-ischemic reactive oxygen species (ROS) level, which were not remarkably reduced. At the same time, cellular energy metabolism did not improve, and the degree of extracellular acidification was not downregulated after administration of compound 1 after PYGB knockdown. In addition, it could neither significantly increase the level of mitochondrial aerobic energy metabolism nor inhibit the expression of apoptosis-associated proteins. The above results indicate that compound 1 could target PYGB to exert its protective effect against cellular H/R injury in mouse astrocytes. Simultaneously, we further demonstrated that PYGB could be an efficient therapeutic target for ischemic-hypoxic diseases. This study provides a new reference for further in-depth study of the action mechanism of the efficacy of compound 1.

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A Novel 5-Chloro-N-phenyl-1H-indole-2-carboxamide Derivative as Brain-Type Glycogen Phosphorylase Inhibitor: Validation of Target PYGB

Huang

et al. 2023

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“…Comparison of the structures of the three isozymes showed that the structure of PYGB is highly similar to the active state of PYGM [ 14 ]. This may be the reason that our previous compound 2 , with its IC 50 value for PYGB, was closer to that of PYGM compared to the IC 50 value for PYGL [ 3 ]. Meanwhile, they also show some differences, such as the tower helix (helix 7 of each monomer), which is a major component of the dimerization interface in GP isozymes, and these two helices show antiparallel binding and control the dimerization and activation of the enzyme.…”

Section: Introductionmentioning

confidence: 86%

“…Therefore, GP was initially considered a potential target for the treatment of type 2 diabetes (T2D) [ 1 ]. Recently, GP inhibitors have also been found to have a positive effect on myocardial ischemia, cerebral ischemia and cancer [ 2 , 3 , 4 ]. In mammals, GP is a family of three isozymes, named brain GP (PYGB), liver GP (PYGL) and muscle GP (PYGM), according to the tissue in which they are expressed, and they exist as active or inactive homodimers ( Figure 1 ) [ 5 ].…”

Section: Introductionmentioning

confidence: 99%

Computational Insights into Novel Inhibitor N-(3-(tert-Butylcarbamoyl)-4-methoxyphenyl)-indole and Ingliforib Specific against GP Isoenzyme Dimers Interaction Mechanism

Yan

et al. 2023

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The high conservation of the three subtypes of glycogen phosphorylase (GP) presents significant challenges for specific inhibitor studies targeting GP. Our prior screening revealed that compound 1 exhibited unequal inhibitory activity against the three GP subtypes, with a noticeable effect against brain GP (PYGB). The commercially available ingliforib demonstrated potent inhibitory activity specifically against liver GP (PYGL). To guide the further design and screening of high-specificity inhibitors, the possible reasons for the differential inhibitory activity of two compounds against different GP subtypes were analyzed, with ingliforib as a reference, through molecular docking and molecular dynamics simulations. Initially, the study predicted the binding modes of ligands with the three GP receptor subtypes using molecular docking. Subsequently, this was validated by molecular dynamics experiments, and possible amino acid residues that had important interactions were explored. The strong correlation between the calculated interaction free energies and experimental inhibitory activity implied the reasonable binding conformations of the compounds. These findings offer insight into the different inhibitory activity of compound 1 and ingliforib against all three GP subtypes and provide guidance for the design of specific target molecules that regulate subtype selectivity.

“…In vitro enzyme activity analysis of compound 1 revealed that it has the best inhibitory activity against PYGB among the three isoforms of glycogen phosphorylase (IC 50 of PYGB, PYGL, and PYGM, which are 90.27 nM, 1537.5 nM, and 144.21 nM, respectively). In a previous study, we conducted an in-depth analysis, which revealed that compound 1 has a cardioprotective effect [ 11 ]. At the same time, by using the ADMET prediction website, we found that compound 1 has high blood–brain barrier permeability (BBB: 3.9803).…”

Section: Introductionmentioning

confidence: 99%

A Novel 5-Chloro-N-phenyl-1H-indole-2-carboxamide Derivative as Brain-Type Glycogen Phosphorylase Inhibitor: Potential Therapeutic Effect on Cerebral Ischemia

Huang

et al. 2022

Self Cite

Brain-type glycogen phosphorylase inhibitors are potential new drugs for treating ischemic brain injury. In our previous study, we reported compound 1 as a novel brain-type glycogen phosphorylase inhibitor with cardioprotective properties. We also found that compound 1 has high blood–brain barrier permeability through the ADMET prediction website. In this study, we deeply analyzed the protective effect of compound 1 on hypoxic-ischemic brain injury, finding that compound 1 could alleviate the hypoxia/reoxygenation (H/R) injury of astrocytes by improving cell viability and reducing LDH leakage rate, intracellular glucose content, and post-ischemic ROS level. At the same time, compound 1 could reduce the level of ATP in brain cells after ischemia, improve cellular energy metabolism, downregulate the degree of extracellular acidification, and improve metabolic acidosis. It could also increase the level of mitochondrial aerobic energy metabolism during brain cell reperfusion, reduce anaerobic glycolysis, and inhibit apoptosis and the expression of apoptosis-related proteins. The above results indicated that compound 1 is involved in the regulation of glucose metabolism, can control cell apoptosis, and has protective and potential therapeutic effects on cerebral ischemia-reperfusion injury, which provides a new reference and possibility for the development of novel drugs for the treatment of ischemic brain injury.