Captopril alleviates oxidative damage in diabetic retinopathy

Nitric oxide mediates negative feedback on the TXNIP/NLRP3 inflammasome pathway to prevent retinal neurovascular unit dysfunction in early diabetic retinopathy

Diabetic retinopathy (DR) is a leading cause of vision impairment in working-age adults, and is driven by complex neurovascular dysfunction. This study aimed to elucidate whether nitric oxide (NO) can modulate the TXNIP/NLRP3 inflammasome pathway and mitigate retinal neurovascular unit (NVU) damage during early DR. In an in vitro co-culture system, silencing TXNIP or NLRP3 in retinal microglia (RMG) significantly upregulated glial cell-derived neurotrophic factor (GDNF) and downregulated inducible nitric oxide synthase (iNOS) expression in retinal ganglion cells (RGC). Moreover, it resulted in decreased iNOS and vascular endothelial growth factor A (VEGFA) levels and enhanced the expression of tight junction proteins (Occludin and ZO-1) in retinal microvascular endothelial cells (RMEC), while also reducing NO release and inhibiting RMEC tube formation. Treatment with S-nitroso-N-acetyl penicillamine (SNAP), an NO donor, significantly downregulated TXNIP/NLRP3 inflammasome signaling in RMG, decreased RGC apoptosis, and inhibited tube formation in RMEC. It also upregulated GDNF, suppressed iNOS in RGC, decreased VEGFA, and improved tight junction proteins in RMEC. Treatment with 1400W, an iNOS inhibitor, resulted in decreased NO concentration and increased IL-1β levels in the co-culture supernatant, without significantly affecting iNOS expression in RGC or RMEC. In an early DR rat model, Electroretinogram (ERG), Optical Coherence Tomography (OCT), Fluorescein Angiography (FFA), Evans blue assays, Immunofluorescence staining, and TUNEL staining confirmed that sodium nitroprusside (SNP), NO donor administration mitigated retinal neural and vascular dysfunction, and preserved retinal NVU integrity. Concurrently, SNP treatment reduced IL-1β expression and increased GDNF and Occludin levels in the early DR retina. Genetic Association Database (GAD) enrichment analysis and protein-protein interaction (PPI) network validation indicated that NO functions as a downstream mediator of the TXNIP/NLRP3 inflammasome pathway and exhibits a strong association with DR. These findings suggest that NO mediates negative feedback in the TXNIP/NLRP3 inflammasome pathway to exert protective effects against retinal NVU dysfunction in early DR, thereby offering potential therapeutic strategies for early intervention in DR.

Regulation of optimized new Shengmai powder on cardiomyocyte apoptosis and ferroptosis in ischemic heart failure rats: The mediating role of phosphatidylinositol-3-kinase/protein kinase B/tumor protein 53 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Optimized New Shengmai Powder (ONSMP) is a sophisticated traditional Chinese medicinal formula renowned for bolstering vital energy, optimizing blood circulation, and mitigating fluid retention. After years of clinical application, ONSMP has shown a significant impact in improving myocardial injury and cardiac function and has a positive effect on treating heart failure. However, many unknowns exist about the molecular biological mechanisms of how ONSMP exerts its therapeutic effects, which require further research and exploration.

AIM OF THE STUDY

Exploring the potential molecular biological mechanisms by which ONSMP ameliorates cardiomyocyte apoptosis and ferroptosis in ischemic heart failure (IHF).

MATERIALS AND METHODS

First, we constructed a rat model of IHF by inducing acute myocardial infarction through surgery and using echocardiography, organ coefficients, markers of heart failure, antioxidant markers, and histopathological examination to assess the effects of ONSMP on cardiomyocyte apoptosis and ferroptosis in IHF rats. Next, we used bioinformatics analysis techniques to analyze the active components, signaling pathways, and core targets of ONSMP and calculated the interactions between core targets and corresponding elements. Finally, we detected the positive expression of apoptosis and ferroptosis markers and core indicators of signaling pathways by immunohistochemistry; detected the mean fluorescence intensity of core indicators of signaling pathways by immunofluorescence; detected the protein expression of signaling pathways and downstream effector molecules by western blotting; and detected the mRNA levels of p53 and downstream effector molecules by quantitative polymerase chain reaction.

RESULTS

ONSMP can activate the Ser83 site of ASK by promoting the phosphorylation of the PI3K/AKT axis, thereby inhibiting the MKK3/6-p38 axis and the MKK4/7-JNK axis signaling to reduce p53 expression, and can also directly target and inhibit the activity of p53, ultimately inhibiting p53-mediated mRNA and protein increases in PUMA, SAT1, PIG3, and TFR1, as well as mRNA and protein decreases in SLC7A11, thereby inhibiting cardiomyocyte apoptosis and ferroptosis, effectively improving cardiac function and ventricular remodeling in IHF rat models.

CONCLUSION

ONSMP can inhibit cardiomyocyte apoptosis and ferroptosis through the PI3K/AKT/p53 signaling pathway, delaying the development of IHF.

Parallelism and non-parallelism in diabetic nephropathy and diabetic retinopathy

Diabetic nephropathy (DN) and diabetic retinopathy (DR), as microvascular complications of diabetes mellitus, are currently the leading causes of end-stage renal disease (ESRD) and blindness, respectively, in the adult working population, and they are major public health problems with social and economic burdens. The parallelism between the two in the process of occurrence and development manifests in the high overlap of disease-causing risk factors and pathogenesis, high rates of comorbidity, mutually predictive effects, and partial concordance in the clinical use of medications. However, since the two organs, the eye and the kidney, have their unique internal environment and physiological processes, each with specific influencing molecules, and the target organs have non-parallelism due to different pathological changes and responses to various influencing factors, this article provides an overview of the parallelism and non-parallelism between DN and DR to further recognize the commonalities and differences between the two diseases and provide references for early diagnosis, clinical guidance on the use of medication, and the development of new drugs.

Identification of the shared molecular mechanisms between major depressive disorder and COVID-19 from postmortem brain transcriptome analysis

OBJECTIVES

This study aims to investigate the molecular mechanisms underlying the interaction of major depressive disorder (MDD) and COVID-19, and on this basis, diagnostic biomarkers and potential therapeutic drugs are further explored.

METHODS

Differential gene expression analysis and weighted gene co-expression network analysis (WGCNA) were employed to identify common key genes involved in the pathogenesis of COVID-19 and MDD. Correlations with clinical features were explored. Detailed mechanisms were further investigated through protein interaction networks, GSEA, and immune cell infiltration analysis. Finally, Enrichr's Drug Signature Database and Coremine Medical were used to predict the potential drugs associated with key genes.

RESULTS

The study identified 18 genes involved in both COVID-19 and MDD. Four key genes (MBP, CYP4B1, ERMN, and SLC26A7) were selected based on clinical relevance. A multi-gene prediction model showed good diagnostic efficiency for the two diseases: AUC of 0.852 for COVID-19 and 0.915 for MDD. GO and GSEA analyses identified specific biological functions and pathways associated with key genes in COVID-19 (axon guidance, metabolism, stress response) and MDD (neuron ensheathment, biosynthesis, glutamatergic neuron differentiation). The key genes also affected immune infiltration. Potential therapeutic drugs, including small molecules and traditional Chinese medicines, targeting these genes were identified.

CONCLUSION

This study provides insights into the complex biological mechanisms underlying COVID-19 and MDD, develops an effective diagnostic model, and predicts potential therapeutic drugs, which may contribute to the prevention and treatment of these two prevalent diseases.

Alleviate oxidative stress in diabetic retinopathy: antioxidant therapeutic strategies

OBJECTIVES

This review outlines the function of oxidative stress in DR and discusses therapeutic strategies to treat DR with antioxidants.

METHODS

Published papers on oxidative stress in DR and therapeutic strategies to treat DR with antioxidants were collected and reviewed via database searching on PubMed.

RESULTS

The abnormal development of DR is a complicated process. The pathogenesis of DR has been reported to involve oxidative stress, despite the fact that the mechanisms underlying this are still not fully understood. Excessive reactive oxygen species (ROS) accumulation can damage retina, eventually leading to DR. Increasing evidence have demonstrated that antioxidant therapy can alleviate the degeneration of retinal capillaries in DR.

CONCLUSION

Oxidative stress can play an important contributor in the pathogenesis of DR. Furthermore, animal experiments have shown that antioxidants are a beneficial therapy for treating DR, but more clinical trial data is needed.

221S-1a inhibits endothelial proliferation in pathological angiogenesis through ERK/c-Myc signaling

Pathological angiogenesis plays a major role in many disease processes, including cancer and diabetic retinopathy. Antiangiogenic therapy is a potential management for pathologic angiogenesis. The novel synthetic compound 221S-1a, derived from captopril, tanshinol and borneol, may have antiangiogenic properties. On the basis of MS, NMR and HPLC analysis, the structure of 221S-1a was identified. The cellular uptake and metabolism of this compound was also observed. Next, the antiangiogenic properties of 221S-1a were evaluated in tumor-xenograft and OIR models in vivo. The inhibitory properties of 221S-1a on endothelial cell proliferation, migration, tube formation and sprouting were detected in vitro. Furthermore, 221S-1a induced G1/S phase arrest was detected by PI staining flow cytometry analysis and Cyclin D, Cyclin E expression. 221S-1a inhibited ERK1/2 activation and nuclear translocation, in addition to downregulation of c-Myc, a transcription factor that regulates cell cycle progression. Molecular docking indicated the interaction of 221S-1a with the ATP-binding site of ERK2, leading to the inhibition of ERK2 phosphorylation and a concomitant inhibition of ERK1 phosphorylation. In conclusion, 221S-1a inhibited the G1/S phase transition by blocking the ERK1/2/c-Myc pathway to reduce tumor and OIR retinal angiogenesis. These novel findings suggest that 221S-1a is a potential pharmacologic candidate for treating pathological angiogenesis.