In silico and in vitro investigations on the protein-protein interactions of glutathione S-transferases with mitogen-activated protein kinase 8 and apoptosis signal-regulating kinase 1

The role of glutathione S-transferases in human disease pathogenesis and their current inhibitors

Glutathione S-transferases (GSTs) are a family of enzymes detoxifying various harmful compounds by conjugating them with glutathione. While primarily beneficial, dysregulation of GST activity or specific isoforms can contribute to disease pathogenesis. The intricate balance of detoxification processes regulated by GSTs is pivotal in cellular homeostasis, whereby dysregulation in these mechanisms can have profound implications for human health. Certain GSTs neutralize carcinogens, shielding cells and potentially preventing tumorigenesis. Polymorphisms in specific GSTs may result in the accumulation of toxic metabolites, exacerbating oxidative stress, inflammation, and DNA damage, notably observed in neurodegenerative diseases like Parkinson's disease. They can also modulate signaling pathways involved in cell proliferation, survival, and apoptosis, with aberrant activity potentially contributing to uncontrolled cell growth and resistance to cell death, thus promoting cancer development. They may also contribute to autoimmune diseases and chronic inflammatory conditions. This knowledge is useful for designing therapeutic interventions and understanding chemoresistance due to GST polymorphisms. A variety of GST inhibitors have been developed and investigated, with researchers actively working on new inhibitors aimed at preventing off-target effects. By leveraging knowledge of the involvement of specific GST isoforms in disease pathogenesis across different populations, more effective and targeted therapeutics can be designed to enhance patient care and improve treatment outcomes.

GSTA2 overexpression alleviates bis (2-ethylhexyl) phthalate (DEHP)-induced male reproductive disorders by inhibiting oxidative stress-mediated cell apoptosis via the activated PI3K/AKT signaling pathway

Male reproductive disorders are responsible for approximately 50% of infertility cases. Bis (2-ethylhexyl) phthalate (DEHP) is a common environmental pollutant known for its reproductive toxicity. Oxidative stress is a key mechanism in response to DEHP exposure. Glutathione S-transferase A2 (GSTA2), a member of the glutathione S-transferase family, has the capacity to detoxify environmental toxins. However, its role in regulating DEHP-induced male reproductive disorders remains unexplored. Next, male mice aged 3 weeks were orally administered with DEHP (500 mg/kg/day) for 14 days to induce male reproductive disorders. We observed a decrease in the GSTA2 expression in the testicular tissues of DEHP-treated mice. To investigate the role of GSTA2 in DEHP exposure, lentiviral vectors carrying GSTA2 sequences (1 × 107 TU/mL, 20 μL) were given to mice on the first day of DEHP treatment. GSTA2 overexpression was found to alleviate testicular damage induced by DEHP, as well as to inhibit oxidative stress and subsequent cell apoptosis. In addition, the PI3K/AKT signaling pathway, which is associated with oxidative stress and DEHP exposure, was activated in DEHP-exposed mice following GSTA2 overexpression. Subsequently, mouse spermatocyte GC-2spd cells with DEHP treatment were used to mimic male reproductive disorders in vitro. Consistently, the GSTA2 expression was decreased in GC-2spd cells with DEHP treatment. GSTA2 overexpression inhibited oxidative stress and cell apoptosis in DEHP-treated GC-2spd cells by activating the PI3K/AKT signaling pathway. Moreover, we discovered that GSTA2 overexpression significantly altered the metabolic profiles of DEHP-treated GC-2spd cells. Collectively, our results suggest that GSTA2 overexpression alleviates DEHP-induced male reproductive disorders by suppressing oxidative stress-mediated cell apoptosis via the PI3K/AKT signaling pathway, providing a novel insight into mitigating reproductive toxicity caused by DEHP exposure.

Glutathione S-transferase: A keystone in Parkinson's disease pathogenesis and therapy

Parkinson's disease is a progressive neurodegenerative disorder that predominantly affects motor function due to the loss of dopaminergic neurons in the substantia nigra. It presents significant challenges, impacting millions worldwide with symptoms such as tremors, rigidity, bradykinesia, and postural instability, leading to decreased quality of life and increased morbidity. The pathogenesis of Parkinson's disease is multifaceted, involving complex interactions between genetic susceptibility, environmental factors, and aging, with oxidative stress playing a central role in neuronal degeneration. Glutathione S-Transferase enzymes are critical in the cellular defense mechanism against oxidative stress, catalysing the conjugation of the antioxidant glutathione to various toxic compounds, thereby facilitating their detoxification. Recent research underscores the importance of Glutathione S-Transferase in the pathophysiology of Parkinson's disease, revealing that genetic polymorphisms in Glutathione S-Transferase genes influence the risk and progression of the disease. These genetic variations can affect the enzymatic activity of Glutathione S-Transferase, thereby modulating an individual's capacity to detoxify reactive oxygen species and xenobiotics, which are implicated in Parkinson's disease neuropathological processes. Moreover, biochemical studies have elucidated the role of Glutathione S-Transferase in not only maintaining cellular redox balance but also in modulating various cellular signalling pathways, highlighting its neuroprotective potential. From a therapeutic perspective, targeting Glutathione S-Transferase pathways offers promising avenues for the development of novel treatments aimed at enhancing neuroprotection and mitigating disease progression. This review explores the evident and hypothesized roles of Glutathione S-Transferase in Parkinson's disease, providing a comprehensive overview of its importance and potential as a target for therapeutic intervention.

Revealing the mechanism of 755-nm long-pulsed alexandrite laser in inhibiting infantile hemangioma endothelial cells through transcriptome sequencing

Laser therapy has shown promising outcomes in treating infantile hemangiomas. However, the molecular mechanisms underlying laser treatment for IH remain incompletely elucidated. This study aimed to unravel the molecular mechanisms of laser therapy in IH treatment. We evaluated the inhibitory effects of laser treatment on the proliferation and promotion of apoptosis in human hemangioma endothelial cells (HemECs) through cell counting kit-8 (CCK-8) assay, Hoechst 33342 staining, and flow cytometric analysis. Transcriptome sequencing analysis of HemECs following laser treatment revealed a significant decrease in the expression level of the GSTM5 gene. The qRT-PCR and western blot analysis also showed that GSTM5 expression in HemECs was downregulated compared to human umbilical vein endothelial cells (HUVECs), and concomitantly, the p62-Nrf2 pathway was suppressed. Using siRNA to downregulate GSTM5 expression, we observed that inhibiting GSTM5 expression could restrain cell proliferation, elevate intracellular ROS levels, and induce apoptosis in HemECs. Furthermore, upon inhibition of the p62-Nrf2 pathway using p62-specific siRNA, a significant decrease in GSTM5 expression and an elevation in intracellular ROS levels were noted in laser-treated HemECs. These findings suggested that laser treatment may operate by inhibiting the p62-Nrf2 pathway, thereby downregulating GSTM5 expression, elevating ROS levels, and consequently inducing apoptosis in HemECs.

In silico and in vivo demonstration of the regulatory mechanism of Qi-Ge decoction in treating NAFLD

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD), a chronic and progressive liver disease, often causes steatosis and steatohepatitis. Qi-Ge decoction (QGD) shows a good effect against NAFLD in the clinic. But the molecular mechanism for QGD in improving NAFLD is unknown.

PURPOSE

This study explored the molecular mechanism of QGD in NAFLD model rats using comprehensive network pharmacology, molecular docking and in vivo verification strategies.

METHODS

Active components and targets of QGD were obtained from public database. The overlapped genes between QGD and NAFLD targets were analyzed by enrichment analysis. Active components and targets were used to predict molecular docking analysis. Finally, seven key targets were screened out and the gene expression were verified in the NAFLD rat's liver tissues after QGD treatment.

RESULTS

Fifty-eight common QGD therapeutic targets were associated with NAFLD. Molecular docking demonstrated that seven targets had strong binding ability for the corresponding active ingredients. GO analysis identified 18 biological process entries, which were mainly related to regulation of lipid storage, lipid localization and peptide transport. KEGG analysis identified multiple signaling pathways, which were mainly associated with tumor necrosis factor signaling and NAFLD. In vivo data confirmed that the effect of QGD in the treatment of NAFLD was mainly exerted through improving liver steatosis and inflammatory cell infiltration. Additionally, QGD upregulated the expression of MAPK8 and ESR1 and downregulated the transcriptional expression of IL6, VEGFA, CASP3, EGFR and MYC. These targets may affect lipid metabolism by regulating lipid storage and inflammation.

CONCLUSION

The integration of results obtained in silico and in vivo indicated that QGD regulates multiple targets, biological processes and signaling pathways in NAFLD, which may represent a complex molecular mechanism by which QGD improves NAFLD.Key messagesQGD intervention is related to multiple biological processes such as inflammation, oxidation and cell apoptosis in NAFLD.Lipid and atherosclerosis, TNF signaling pathway, IL-17 signaling pathway, non-alcoholic fatty liver disease and AGE-RAGE signaling pathway in diabetic complications are the main pathways for QGD intervention NAFLD.The active components of QGD can form good binding with relevant target proteins through intermolecular forces, exhibiting excellent docking activity.

A 69 kb Deletion in chr19q13.42 including PRPF31 Gene in a Chinese Family Affected with Autosomal Dominant Retinitis Pigmentosa

We aimed to identify the genetic cause of autosomal dominant retinitis pigmentosa (adRP) and characterize the underlying molecular mechanisms of incomplete penetrance in a Chinese family affected with adRP. All enrolled family members underwent ophthalmic examinations. Whole-genome sequencing (WGS), multiplex ligation-dependent probe amplification (MLPA), linkage analysis and haplotype construction were performed in all participants. RNA-seq was performed to analyze the regulating mechanism of incomplete penetrance among affected patients, mutation carriers and healthy controls. In the studied family, 14 individuals carried a novel heterozygous large deletion of 69 kilobase (kb) in 19q13.42 encompassing exon 1 of the PRPF31 gene and five upstream genes: TFPT, OSCAR, NDUFA3, TARM1, and VSTM1. Three family members were sequenced and diagnosed as non-penetrant carriers (NPCs). RNA-seq showed significant differential expression of genes in deletion between mutation carriers and healthy control. The RP11 pedigree in this study was the largest pedigree compared to other reported RP11 pedigrees with large deletions. Early onset in all affected members in this pedigree was considered to be a special phenotype and was firstly reported in a RP11 family for the first time. Differential expression of PRPF31 between affected and unaffected subjects indicates a haploinsufficiency to cause the disease in the family. The other genes with significant differential expression might play a cooperative effect on the penetrance of RP11.

Ligandability Assessment of Human Glutathione Transferase M1-1 Using Pesticides as Chemical Probes

Glutathione transferases (GSTs; EC 2.5.1.18) form a group of multifunctional enzymes that are involved in phase II of the cellular detoxification mechanism and are associated with increased susceptibility to cancer development and resistance to anticancer drugs. The present study aims to evaluate the ligandability of the human GSTM1-1 isoenzyme (hGSTM1-1) using a broad range of structurally diverse pesticides as probes. The results revealed that hGSTM1-1, compared to other classes of GSTs, displays limited ligandability and ligand-binding promiscuity, as revealed by kinetic inhibition studies. Among all tested pesticides, the carbamate insecticide pirimicarb was identified as the strongest inhibitor towards hGSTM1-1. Kinetic inhibition analysis showed that pirimicarb behaved as a mixed-type inhibitor toward glutathione (GSH) and 1-chloro-2,4-dinitrobenzene (CDNB). To shine a light on the restricted hGSTM1-1 ligand-binding promiscuity, the ligand-free crystal structure of hGSTM1-1 was determined by X-ray crystallography at 1.59 Å-resolution. Comparative analysis of ligand-free structure with the available ligand-bound structures allowed for the study of the enzyme's plasticity and the induced-fit mechanism operated by hGSTM1-1. The results revealed important structural features of the H-site that contribute to xenobiotic-ligand binding and specificity. It was concluded that hGSTM1-1 interacts preferentially with one-ring aromatic compounds that bind at a discrete site which partially overlaps with the xenobiotic substrate binding site (H-site). The results of the study form a basis for the rational design of new drugs targeting hGSTM1-1.