OGG1 in the Kidney: Beyond Base Excision Repair

OGG1: An emerging multifunctional therapeutic target for the treatment of diseases caused by oxidative DNA damage

Oxidative DNA damage-related diseases, such as incurable inflammation, malignant tumors, and age-related disorders, present significant challenges in modern medicine due to their complex molecular mechanisms and limitations in identifying effective treatment targets. Recently, 8-oxoguanine DNA glycosylase 1 (OGG1) has emerged as a promising multifunctional therapeutic target for the treatment of these challenging diseases. In this review, we systematically summarize the multiple functions and mechanisms of OGG1, including pro-inflammatory, tumorigenic, and aging regulatory mechanisms. We also highlight the potential of OGG1 inhibitors and activators as potent therapeutic agents for the aforementioned life-limiting diseases. We conclude that OGG1 serves as a multifunctional hub; the inhibition of OGG1 may provide a novel approach for preventing and treating inflammation and cancer, and the activation of OGG1 could be a strategy for preventing age-related disorders. Furthermore, we provide an extensive overview of successful applications of OGG1 regulation in treating inflammatory, cancerous, and aging-related diseases. Finally, we discuss the current challenges and future directions of OGG1 as an emerging multifunctional therapeutic marker for the aforementioned challenging diseases. The aim of this review is to provide a robust reference for scientific researchers and clinical drug developers in the development of novel clinical targeted drugs for life-limiting diseases, especially for incurable inflammation, malignant tumors, and age-related disorders.

Quercetin-primed BMSC-derived extracellular vesicles ameliorate chronic liver damage through miR-136-5p and GNAS/STAT3 signaling pathways

BACKGROUND

Chronic liver damage (CLD) is a long-term and progressive liver condition characterized by inflammation, fibrosis, and impaired liver function, which ultimately lead to severe complications such as cirrhosis or liver cancer. Quercetin (Que), a flavonoid in various plants, possesses anti-inflammatory, antiviral, anti-ischemic, and anticancer properties. Recently, extracellular vesicles (EVs) derived from pretreated bone marrow mesenchymal stem cells (BMSCs) have shown immense potential in treating various diseases, including CLD. Thus, this study evaluated the regulatory effects of Que-preconditioned BMSC-derived EVs (Que-EVs) on LPS-stimulated RAW264.7 cells and their therapeutic effects on mice with CLD.

METHODS

Que-EVs and control-EVs were harvested from the cell culture supernatant of BMSCs. The EVs were characterized using western blot, transmission electron microscopy, and nanoparticle tracking analysis. Further, the DIR labeling of EVs was used to detect in vitro and in vivo uptake. Next, LPS pre-stimulated RAW264.7 cells were treated with Que-EVs and control-EVs for 24 h. The relative expression of inflammatory cytokines and macrophage polarization markers genes was assessed using RT-qPCR, and western blot was conducted to evaluate the GNAS, PI3K, ERK, and STAT3 gene and protein expressions in RAW264.7 cells. Furthermore, transfection techniques were employed to induce miR-136-5p inhibition and GNAS overexpression in RAW264.7 cells to validate the role of miR-136-5p in alleviating inflammation through the GNAS/PI3K/ERK/STAT3 pathway. Subsequently, the outcomes were validated via in vitro experiments.

RESULTS

Que enhanced miR-136-5p expression in BMSC-EVs. Furthermore, it was shown that EVs delivered miR-136-5p to macrophages, thereby attenuating M1-type macrophage polarisation through the GNAS/PI3K/ERK/STAT3 pathway, reducing liver inflammation, improving liver function and treating CLD.

Catecholamines-based myocardial injury after acute ischemic stroke and effects of Naoxintong capsule therapy

BACKGROUND

Myocardial injury (MI) after acute ischemic stroke (AIS) poses a significant threat to patient prognosis. However, effective intervention strategies are currently lacking.

PURPOSE

To elucidate the mechanism of MI after AIS and effects of Naoxintong capsule (NXT) therapy.

METHOD

In vivo, after a rat model of middle cerebral artery occlusion (MCAO)-induced MI was established and assessed. NXT was administered prophylactically to evaluate its pharmacodynamic effects and mechanisms. In vitro, a noradrenaline (NA)-induced damage cell model was constructed. Subsequently, the NXT was applied to the cell models to examine its cardioprotective effects and potential mechanisms.

RESULTS

The in vivo findings revealed that following MCAO, there was a notable upregulation of TH expression in the rat brain, which subsequently triggered an increase in serum levels of various biomarkers, including AD, NA, AST, cTnT, CK-MB, and NT-proBNP. Histological analysis employing H&E staining and TUNEL assay disclosed significant pathological alterations and an escalation in apoptotic activity within the myocardial tissue. The myocardial tissue exhibited elevated levels of MDA alongside diminished CAT activity. Additionally, a marked increase in the Bax/Bcl-2 ratio, Cytochrome C release, and Caspase-3 activation was observed, all of which are indicative of heightened apoptotic activity. Administration of the NXT intervention successfully attenuated TH expression in the brains of rats subjected to MCAO, consequently leading to a reduction in circulating levels of catecholamines (CAs). NXT also exhibited significant efficacy at ameliorating cardiac oxidative stress and reducing apoptosis. In vitro, stimulation with NA led to an increase in ROS levels and calcium ion concentration in H9c2 cardiomyocytes. However, the administration of NXT has been found to effectively alleviate these adverse effects, thereby protecting H9c2 cardiomyocytes from the deleterious consequences of oxidative stress and calcium dyshomeostasis.

CONCLUSION

Overall, this study has demonstrated that increased CAs synthesis in the brain after AIS in experimental rats led to a surge in circulating CAs, ultimately leading to MI. NXT can alleviate MI due to cerebral ischemia by increasing improving brain catecholamine synthesis, cardiac oxidative stress, and apoptosis.

Clinicopathologic and prognostic implications of HOXA gene and its associated long-noncoding RNAs expression in non-small cell carcinoma: A meta-analysis

BACKGROUND

We conducted an investigation into the correlation between HOXA and associated long-noncoding RNAs, along with their clinicopathologic and prognostic features in non-small cell lung cancer (NSCLC).

METHODS

A comprehensive search across multiple electronic databases, including PubMed and the Web of Science, was conducted to identify relevant studies. The association between HOXA, clinicopathologic parameters, and prognosis was assessed using relative risk (RR) and hazard ratio (HR) with a 95% confidence interval (CI). Data compilation was performed using STATA 12.0 software.

RESULTS

A total of 11 trials involving 2058 patients with NSCLC were included in our study. Significant correlations were observed between HOXA-AS2 and TNM stage (III-IV) (RR=2.173, 95% CI: 1.386-5.437, P< 0.05) and HOTTIP and age (≥60-year-old) (RR=2.628, 95% CI: 1.185-5.829, P< 0.05) and non-smoking (RR=0.387, 95% CI: 0.156-0.959, P< 0.05). The combined results indicated a significant association between HOXA5 and increased overall survival (HR = 0.69, 95% CI = 0.57-0.84, P < .001). Additionally, HOXA-AS2, HOXA11 and HOTTIP were identified as potential independent predictors for poorer OS (HOXA-AS2: HR =3.48, 95% CI = 1.95 to 6.21, P < 0.05; HOXA11: HR=1.39, 95%CI = 1.08 to 1.79, P < 0.05; HOTTIP: HR=2.44, 95%CI = 1.10 to 5.42, P < 0.05). The prognostic significance of HOXA1, HOXA3 and HOXA4 was uncertain (HOXA1: HR=1.40, 95% CI =0.28 to 7.06, P > 0.05; HOXA3: HR=1.20, 95% CI = 0.96 to 1.50, P > 0.05; HOXA4: HR=0.97, 95% CI = 0.77 to 1.23, P > 0.05).

CONCLUSIONS

The HOXA gene family has some potential to emerge as a novel prognostic factor for NSCLC and is correlated with some clinicopathological parameters such as the TNM stage, age and smoking. However, further meticulously designed prospective studies are warranted to substantiate these findings.

Puerarin inhibits Staphylococcus aureus-induced endometritis through attenuating inflammation and ferroptosis via regulating the P2X7/NLRP3 signalling pathway

Endometritis is one of the important causes of infertility. Puerarin (PU) can inhibit oxidative stress and reduce inflammation; however, it is unclear whether PU has a protective effect on the endometritis. In our study, we used Staphylococcus aureus to induce mouse endometritis. The PU group (100 mg/kg PU) and the S. aureus + PU group received daily intraperitoneal injection of PU (25, 50 or 100 mg/kg PU). The results showed that S. aureus significantly increased the levels of MPO, TNF-α, IL-1β and IL-6 in uterine tissue, and increased the expression of p-p65 and p-IκBα proteins in uterine tissue to induce endometritis in mice (p < 0.05). Furthermore, it has been found that S. aureus promotes the occurrence of ferroptosis by reducing GSH and ATP content, increasing MDA and iron content and reducing GPX4 and SLC7A11 protein expression levels (p < 0.05). S. aureus significantly increase the expression of NLRP3, ASC, caspase-1 and P2X7 proteins in uterine tissue (p < 0.05). However, PU obviously reduced the inflammatory response and reversed the changes of ferroptosis and the expression of P2X7 receptor/NLRP3 pathway associated proteins of the uterus induced by S. aureus (p < 0.05). Taken together, these findings emphasize the protective effect of PU on endometritis by regulating the P2X7 receptor/NLRP3 signalling pathway and inhibiting ferroptosis.

Exploring the action mechanism of Gegensan in the treatment of alcoholic liver disease based on network pharmacology and bioinformatics

Gegensan (GGS) has been reported for the treatment of alcoholic liver disease (ALD), but its therapeutic mechanism is still unclear. This paper aims to determine the therapeutic mechanism and targets of action of GGS on alcoholic liver disease utilizing network pharmacology and bioinformatics. The active ingredients in GGS were screened in the literature and databases, and common targets of ALD were then obtained from public databases to construct the network diagram of traditional Chinese medicine-active ingredient targets. Based on the common targets, Gene Ontology enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed to find target enrichment pathways, and the core targets were screened out by combining differential analysis and protein-protein interaction network analysis. Molecular docking was performed to verify the binding effect between the core targets and the corresponding active ingredients. ALD and GGS have 84 common targets, corresponding to 91 active ingredients. After subsequent differential analysis and protein-protein interaction network analysis, 10 core targets were identified. Gene Ontology and KEGG enrichment analyses showed that the main BPs corresponding to the common targets included the response to lipopolysaccharide, inflammatory response, etc. The KEGG pathways involved in the regulation of the common targets included the lipid-atherosclerosis pathway and the alcoholic liver disease pathway, etc. Further molecular docking showed that the core targets CYP1A1, CYP1A2, CXCL8, ADH1C, MMP1, SERPINE1, COL1A1, APOB, MMP1, and their corresponding 4 active ingredients, Naringenin, Kaempferol, Quercetin, and Stigmasterol, have a greater docking potential. The above results suggest that GGS can regulate lipid metabolism and inflammatory response in the ALD process, and alleviate the lipid accumulation and oxidative stress caused by ethanol. This study analyzed the core targets and mechanisms of action of GGS on ALD, which provides certain theoretical support for the further development of GGS in the treatment of ALD, and provides a reference for the subsequent research on the treatment of ALD.

Investigation of APE1 and OGG1 expression in chronic hemodialysis patients

BACKGROUND

The role of DNA repair mechanisms is of significant importance in diseases characterized by elevated oxidative DNA damage, such as chronic kidney disease. It is imperative to thoroughly understand the functions of molecules associated with DNA repair mechanisms, not only for assessing susceptibility to diseases but also for monitoring disease progression. In this research, we investigated the APE1 and OGG1 gene expression levels, both of which are involved in the base excision repair (BER) mechanism in chronic hemodialysis patients with malignancy (HPM; n = 8) and without malignancy (HP; n = 36) in pre- and post-dialysis period and 37 healty persons. We also assessed how these values correlate with the clinical profiles of the patients.

METHODS AND RESULTS

We conducted gene expression analysis using real-time polymerase chain reaction (qRT-PCR). No significant differences in APE1 gene expression levels were observed in pre-dialysis when comparing the HP and HPM groups to the control group. The expression levels of the OGG1 gene were significantly lower in both the HP and HPM groups in pre- and post-dialysis periods compared to the control group. Dialysis procedures led to a reduction in APE1 and OGG1 gene expression levels in both HP and HPM groups.

CONCLUSIONS

The findings of our study elucidate the impact of alterations in the base excision repair (BER) mechanism, including the hemodialysis process, in end-stage renal disease (ESRD).

The Anticancer Effects of the Garlic Organosulfide Diallyl Trisulfide through the Attenuation of B[a]P-Induced Oxidative Stress, AhR Expression, and DNA Damage in Human Premalignant Breast Epithelial (MCF-10AT1) Cells

Benzo[a]pyrene (B[a]P) is the most characterized polycyclic aromatic hydrocarbon associated with breast cancer. Our lab previously reported that the organosulfur compound (OSC), diallyl trisulfide (DATS), chemoprevention mechanism works through the induction of cell cycle arrest and a reduction in oxidative stress and DNA damage in normal breast epithelial cells. We hypothesize that DATS will inhibit B[a]P-induced cancer initiation in premalignant breast epithelial (MCF-10AT1) cells. In this study, we evaluated the ability of DATS to attenuate B[a]P-induced neoplastic transformation in MCF-10AT1 cells by measuring biological endpoints such as proliferation, clonogenicity, reactive oxygen species (ROS) formation, and 8-hydroxy-2-deoxyguanosine (8-OHdG) DNA damage levels, as well as DNA repair and antioxidant proteins. The results indicate that B[a]P induced proliferation, clonogenic formation, ROS formation, and 8-OHdG levels, as well as increasing AhR, ARNT/HIF-1β, and CYP1A1 protein expression compared with the control in MCF-10AT1 cells. B[a]P/DATS's co-treatment (CoTx) inhibited cell proliferation, clonogenic formation, ROS formation, AhR protein expression, and 8-OHdG levels compared with B[a]P alone and attenuated all the above-mentioned B[a]P-induced changes in protein expression, causing a chemopreventive effect. This study demonstrates, for the first time, that DATS prevents premalignant breast cells from undergoing B[a]P-induced neoplastic transformation, thus providing more evidence for its chemopreventive effects in breast cancer.

OGG1 prevents atherosclerosis-induced vascular endothelial cell injury through mediating DNA damage repair

OBJECTIVE

This study was designed to investigate the role of 8-oxoguanine DNA glycosylase 1 (OGG1) in preventing atherosclerosis-induced vascular EC injury, thereby providing a theoretical basis for the exploration of drug targets and treatment methods for atherosclerosis.

METHODS

Human umbilical vein cell line (EA.hy926) was treated with ox-LDL to construct an in vitro atherosclerotic cell model. pcDNA3.1-OGG1 was transfected into EA.hy926 cells to overexpress OGG1. qRT-PCR, CCK-8 assay, flow cytometry, oil red O staining, ELISA, comet assay and western blot were used to evaluate the OGG1 expression, viability, apoptosis level, lipid droplet content, 8-OHdG level and DNA damage of cells in each group.

RESULTS

Compared with the Control group, ox-LDL stimulation of endothelial cells significantly decreased cell viability, promoted apoptosis and DNA damage, and increased intracellular levels of 8-OHdG and γH2AX, while decreasing protein levels of PPARγ, FASN, FABP4, RAD51 and POLB. However, overexpression of OGG1 can significantly inhibit ox-LDL damage to endothelial cells, promote lipid metabolism, decrease lipid droplet content, and improve DNA repair function.

CONCLUSION

Over-expression of OGG1 improves DNA repair. Briefly, OGG1 over-expression enhances the DNA damage repair of ECs by regulating the expression levels of γH2AX, RAD51 and POLB, thereby enhancing cell viability and reducing apoptosis.

An Update on Recent Studies Focusing on the Antioxidant Properties of Salvia Species

Nutrition has crucial effects and a significant role in disease prevention. Recently, nutraceuticals have attracted much attention in scientific research due to their pleiotropic effects and relatively non-toxic behavior. Among the biological effects displayed by plants belonging to the Lamiaceae family, such as antibacterial, anticancer, anti-inflammatory, and anticholinesterase, sage is well known for its antioxidant properties and is a rich source of numerous compounds that are biologically active, amongst them polyphenols, with more than 160 types identified. In this review we summarized some of the significant studies published in the last decade reporting the most employed extraction methods and the different assays that are useful for establishing the antioxidant properties of some sage species. Even though the scientific literature contains plenty of data regarding the antioxidant properties of many sage species, further studies are needed in order to gain a deeper understanding of the mechanism of action and the compounds responsible for their antioxidant activity. Finally, it should be taken into account that the data on the antioxidant properties of sage extracts are often difficult to compare with each other, since a series of variables in the extraction procedures, the type of assay used, and standardization may affect the final result.

Mechanistic study of dual-function inhibitors targeting topoisomerase II and Rad51-mediated DNA repair pathway against castration-resistant prostate cancer

BACKGROUND

Castration-resistant prostate cancer (CRPC) is refractory to hormone treatment and the therapeutic options are continuously advancing. This study aims to discover the anti-CRPC effects and underlying mechanisms of small-molecule compounds targeting topoisomerase (TOP) II and cellular components of DNA damage repair.

METHODS

Cell proliferation was determined in CRPC PC-3 and DU-145 cells using anchorage-dependent colony formation, sulforhodamine B assay and flow cytometric analysis of CFSE staining. Flow cytometric analyses of propidium iodide staining and JC-1 staining were used to examine the population of cell-cycle phases and mitochondrial membrane potential, respectively. Nuclear extraction was performed to detect the nuclear localization of cellular components in DNA repair pathways. Protein expressions were determined using Western blot analysis.

RESULTS

A series of azathioxanthone-based derivatives were synthesized and examined for bioactivities in which WC-A13, WC-A14, WC-A15, and WC-A16 displayed potent anti-CRPC activities in both PC-3 and DU-145 cell models. These WC-A compounds selectively downregulated both TOP IIα and TOP IIβ but not TOP I protein expression. WC-A13, WC-A14, and WC-A15 were more potent than WC-A16 on TOP II inhibition, mitochondrial dysfunction, and induction of caspase cascades indicating the key role of amine-containing side chain of the compounds in determining anti-CRPC activities. Furthermore, WC-A compounds induced an increase of γH2AX and activated ATR-Chk1 and ATM-Chk2 signaling pathways. P21 protein expression was also upregulated by WC-A compounds in which WC-A16 showed the least activity. Notably, WC-A compounds exhibited different regulation on Rad51, a major protein in homologous recombination of DNA in double-stranded break repair. WC-A13, WC-A14, and WC-A15 inhibited, whereas WC-A16 induced, the nuclear translocation of Rad51.

CONCLUSION

The data suggest that WC-A compounds exhibit anti-CRPC effects through the inhibition of TOP II activities, leading to mitochondrial stress-involved caspase activation and apoptosis. Moreover, WC-A13, WC-A14, and WC-A15 but not WC-A16 display inhibitory activities of Rad51-mediated DNA repair pathway which may increase apoptotic effect of CRPC cells.

Research Progress of Pyroptosis in Fatty Liver Disease

Fatty liver disease (FLD) is a clinical and pathological syndrome characterized by excessive fat deposition and even steatosis in hepatocytes. It has been proven that liver inflammation induced by fat and its derivatives are involved in the pathogenesis of FLD, while the precise mechanism still remains poorly understood. Pyroptosis is programmed inflammatory cell death driving cell swelling and membrane rupture. Pyroptosis is initiated by the activation of inflammasomes and caspases, which further cleaves and activates various gasdermins, leading to pores forming on the cell membrane and the release of pro-inflammatory factors such as interleukin (IL)-1β and IL-18. Recent studies demonstrate that pyroptosis occurs in hepatocytes, and inhibiting pyroptosis could effectively reduce fat deposition in the liver and could ameliorate inflammation from FLD, attracting our prime focus on the role of pyroptosis in FLD. In this manuscript, we reviewed the current understanding of pyroptosis in FLD development, aiming to provide new insights and potential research targets for the clinical diagnosis and intervention of FLD.

Epimedium sagittatum Maxim ameliorates adriamycin-induced nephropathy by restraining inflammation and apoptosis via the PI3K/AKT signaling pathway

BACKGROUND

Modern pharmacological studies show that Epimedium sagittatum Maxim (EPI) has antioxidant, antiapoptotic, anti-inflammatory effects. However, the effects of EPI on adriamycin-induced nephropathy are unclear.

AIM

The main purpose of this study is to investigate the effects of EPI on adriamycin-induced nephropathy in rats.

METHODS

The chemical composition of EPI was detected by high performance liquid chromatography. Network pharmacology was used to collect the effects of EPI on adriamycin nephropathy; renal histological changes, podocyte injury, inflammatory factors, oxidative stress levels, apoptosis levels, and the PI3K/AKT signaling pathway were examined. Moreover, analyze the effects of icariin (the representative component of EPI) on adriamycin-induced apoptosis and PI3K/AKT signaling pathway of NRK-52e cells.

RESULTS

Network pharmacological results suggested that EPI may ameliorate adriamycin-induced nephropathy by inhibiting inflammatory response and regulating the PI3K/AKT signaling pathway. The experimental results showed that EPI could improve pathological injury, renal function, podocyte injury, and inhibit inflammation, oxidative stress, apoptosis in adriamycin-induced nephropathy rats through the PI3K/AKT signaling pathway. Furthermore, icariin inhibited adriamycin-induced mitochondrial apoptosis in NRK-52e cells.

CONCLUSION

This study suggested that EPI ameliorates adriamycin-induced nephropathy by reducing inflammation and apoptosis through the PI3K/AKT signaling pathway, icariin may be the pharmacodynamic substance basis for this effect.

Parishin A-loaded mesoporous silica nanoparticles modulate macrophage polarization to attenuate tendinopathy

Macrophages are involved mainly in the balance between inflammation and tenogenesis during the healing process of tendinopathy. However, etiological therapeutic strategies to efficiently treat tendinopathy by modulating macrophage state are still lacking. In this study, we find that a small molecule compound Parishin-A (PA) isolated from Gastrodia elata could promote anti-inflammatory M2 macrophage polarization by inhibiting gene transcription and protein phosphorylation of signal transducers and activators of transcription 1. Local injection or sustained delivery of PA by mesoporous silica nanoparticles (MSNs) could almost recover the native tendon's dense parallel-aligned collagen matrix in collagenase-induced tendinopathy by modulating macrophage-mediated immune microenvironment and preventing heterotopic ossification. Especially, MSNs decrease doses of PA, frequency of injection and yield preferable therapeutic effects. Mechanistically, intervention with PA could indirectly inhibit activation of mammalian target of rapamycin to repress chondrogenic and osteogenic differentiation of tendon stem/progenitor cells by influencing macrophage inflammatory cytokine secretion. Together, pharmacological intervention with a natural small-molecule compound to modulate macrophage status appears to be a promising strategy for tendinopathy treatment.

Glyphosate-triggered hepatocyte ferroptosis via suppressing Nrf2/GSH/GPX4 axis exacerbates hepatotoxicity

Glyphosate (GLY) exposure has been reported to damage organs in animals, in particular the liver, due to increased reactive oxygen species (ROS). Ferroptosis is defined as a new type of cell death that is characterized by the increase of ROS. The purpose of this study was to elucidate whether the relationship between ferroptosis and GLY-induced hepatotoxicity is of significance to enlarge the knowledge about GLY toxicity and consequences for human and animal health. To this end, in this study, we investigated the role of ferroptosis in GLY-induced hepatotoxicity both in vivo and in vitro. The results showed that GLY exposure triggered ferroptosis in L02 cells, but pretreatment with ferroptosis inhibitor ferrostatin (Fer-1) rescued ferroptosis-induced injury, thereby indicating that ferroptosis plays a key role in GLY-induced hepatotoxicity. Moreover, N-acetylcysteine, a glutathione (GSH) synthesis precursor, reversed GLY-triggered ferroptosis damage, thus indicating that GSH exhaustion may be a prerequisite for GLY-triggered hepatotoxicity. Mechanistically, GLY inhibited GSH biosynthesis via blocking the phosphorylation and nuclear translocation of Nrf2, which resulted in GSH depletion-induced hepatocyte ferroptosis. In a mouse model, GLY exposure triggered ferroptosis-induced liver damage, which can be rescued by pretreatment with Fer-1 or tBHQ (a specific agonist of Nrf2). To our knowledge, this is the first study to reveal that GLY-triggered hepatocyte ferroptosis via suppressing Nrf2/GSH/GPX4 axis exacerbates hepatotoxicity, which expands our knowledge about GLY toxicity in animal and human health.