Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie最新文献

Ischemia-reperfusion (I/R) injury exacerbates tissue damage upon reperfusion after ischemia. The effects of chemerin and its receptor, chemokine-like receptor 1 (CMKLR1), on I/R injury remain poorly understood. We hypothesized that the chemerin-CMKLR1 axis differentially regulates signaling in microglia and neuronal cells during oxygen-glucose deprivation/reoxygenation (OGD/R), influencing mitochondrial function, oxidative stress, and autophagy. Using BV2 microglia and Neuro-2a (N2a) neuronal cells, we examined OGD/R-induced changes in the expression of the autophagy-associated proteins chemerin and CMKLR1. We investigated the functional consequences of CMKLR1 overexpression and chemerin treatment on oxidative stress, apoptosis, autophagy, and mitochondrial dynamics in BV2 microglia and N2a neuronal cells. Following OGD/R, CMKLR1 expression was downregulated, whereas autophagy was upregulated in both cell types. In contrast, chemerin expression decreased in BV2 microglia but increased in N2a cells. Treatment with chemerin dose-dependently reduced oxidative stress and apoptosis while enhancing mitochondrial fusion, suppressing fission, and promoting autophagy and mitochondrial function in both cell types under OGD/R conditions. CMKLR1 overexpression exacerbated mitochondrial respiratory dysfunction, mitochondrial fusion, fission, and increased autophagy (LC3II/LC3I and Pink1 levels), with cell type-specific differences observed in Parkin and P62 regulation. Our study revealed cell type-specific regulation of chemerin-CMKLR1 signaling in I/R injury and distinct mitophagy activation mechanisms in microglia and neurons. These findings suggest that the cell type-specific modulation of chemerin-CMKLR1 is a potential therapeutic target for preserving mitochondrial homeostasis; modulating autophagy and mitophagy; and reducing oxidative stress and apoptosis in both microglia and neurons to mitigate I/R injury.

Despite the development of Coronavirus Disease 2019 (COVID-19) vaccines, the search for a definitive cure continues. 6'-Hydroxy justicidin B (6'-HJB), found in Justicia procumbens and used in Chinese medicine for its antiviral properties, shows promise as a therapeutic candidate against COVID-19. Nevertheless, it is crucial to establish its safety profile before clinical trials. This study evaluated its safety through non-clinical Good Laboratory Practice genotoxicity and rodent toxicity studies. The results indicated that 6'-HJB is not genotoxic, supporting its safety for future clinical use. The compound exhibited a low risk of DNA damage, a critical concern in drug development. Extensive toxicity studies, including single and repeated oral doses in Sprague Dawley rats, showed that the lethal dose of 6'-HJB exceeded 2000 mg/kg, with no observed adverse effects at this level. Safety data from genotoxicity and rodent toxicity studies strongly support further investigation of 6'-HJB as a novel treatment for COVID-19. 6'-HJB is expected to serve as a promising therapeutic option for overcoming future emerging viral infectious diseases.

Diphtheria toxin (DT), an AB-type protein exotoxin, is the main virulence factor of Corynebacterium diphtheriae and the causative agent of diphtheria, a life-threatening disease especially in children. DT binds to its receptor heparin-binding EGF-like growth factor on human target cells via its binding subunit DTB, enters cells by receptor-mediated endocytosis and delivers its enzyme subunit DTA into the cytosol. There, DTA catalyzes the ADP-ribosylation of elongation factor 2, which inhibits protein synthesis and leads to cell death. The number of diphtheria cases is increasing worldwide despite routine vaccination against DT in many countries. Although diphtheria mortality is significantly reduced by standard diphtheria antitoxin therapy, there are drawbacks to this therapy and new therapeutic strategies are highly desirable. In this study, we identified the approved anticoagulant drug fondaparinux, the pharmacologically active pentasaccharide sequence within heparin, as potent inhibitor against DT in vitro. Fondaparinux protected eukaryotic cells from intoxication with DT, whereas unfractionated and low molecular weight heparins did not. When DT was applied to cells in the presence of fondaparinux, the ADP-ribosylation of elongation factor 2 was significantly reduced in these cells and their protein synthesis was maintained. By investigating the inhibitory mechanisms of fondaparinux against DT, we found that fondaparinux prevented DT binding to cells and thus DT uptake. As fondaparinux is a licensed drug with well-known toxicity and pharmacokinetic profiles, these findings should provide a starting point for the development of novel pharmacological strategies to treat diphtheria, which is considered a re-emerging disease, also in western countries.

Dual inhibition of VEGFR-2 and Aurora A is a promising strategy for treating complex malignancies like hepatocellular carcinoma (HCC) and breast cancer. In this study, a series of new pyrazolopyrimidine derivatives were designed and synthesized via a one-pot multicomponent reaction using both conventional and microwave-assisted techniques. Structural characterization was confirmed by spectroscopic data. The compounds were evaluated as dual inhibitors of Aurora A and VEGFR-2 kinases through molecular docking, in vitro cytotoxicity assays, and expression analysis. Docking simulations revealed compound 5b had the strongest binding affinity for both kinases. Consistently, MTT assays showed that compounds 5b, 5c, and 6b exhibited potent cytotoxicity, with compound 5b displaying the highest activity against HepG2 and MCF-7 cells (IC₅₀ = 3.0 μM and 3.5 μM, respectively). In particular, in HepG2 cells, compound 5b inhibited VEGFR-2 by 86.3 % and Aurora A by 66.7 %, demonstrating stronger dual-target inhibition compared to the reference compound, sunitinib. Furthermore, compound 5b significantly downregulated VEGFR-2 and Aurora A protein and gene expression. Toxicity evaluation in vivo indicated no lethal effects at doses up to 1000 mg/kg, with an LD₅₀ exceeding 1500 mg/kg, suggesting a favorable safety profile. These findings identify compound 5b as a promising dual-target inhibitor and potential lead candidate for the treatment of HCC and breast cancer.

Purpose: Recurrent refractory testicular germ cell tumors (rrTGCT) represent very rare disease with limited therapeutic options. Antibody-drug conjugate Sacituzumab govitecan (ADC-SG) targeting TROP2 protein (TACSTD2 gene) demonstrated anti-tumor activity in solid tumors. Our study aimed to investigate efficacy of ADC-SG in rrTGCT.

Experimental design: TROP2 expression in tumor samples (n = 71) and cell line-derived xenografts (CDXs) by immunohistochemistry (IHC); and TACSTD 2 expression by qRT-PCR was determined. Cytotoxicity was evaluated in adherent and spheroid conditions. We generated CDXs, TGCT cell-derived metastatic model, and TGCT patient-derived xenografts (PDXs, n = 4) to test ADC-SG cytotoxic activity in vivo. Clinical efficacy of the ADC-SG was evaluated in a rrTGCT patient with progressive disease.

Results: TROP2 expression was confirmed in 98.6 % of TGCTs with significantly higher expression in tumor compared to normal testis, and in non-seminoma versus seminoma (p = 0.00007). TROP2 expression is ubiquitous in GCTs without any significant correlation to overall or disease-free survival, tumor grade or tumor stage. TROP2 was significantly increased in cisplatin (CPT) resistant CDXs. ADC-SG exhibited cytotoxicity at nanomolar concentrations in vitro. ADC-SG treatment significantly increased survival in a metastatic model derived from TGCT cells and decreased PDXs' volume (n = 4). Our case study demonstrated tumor regression accompanied by decrease in serum markers, reduction in lesion size, and improved ECOG performance status in the rrTGCT patient with progressive disease treated with ADC-SG.

Conclusion: Our preclinical work on CDX and PDX together with proof-of-concept clinical case provide rationale for further studies. Refractory relapsing TGCTs represent another clinical entity for treatment with ADC-SG.

Pancreatic ductal adenocarcinoma (PDAC) is the third primary cause of cancer-related mortality in the US. PDAC is associated with an immunosuppressive tumor microenvironment (TME) that restricts the effectiveness of immunotherapies. Immunosuppressive tumor-associated macrophages (TAMs), the most abundant cell type in TME, express immune checkpoint ligands, including programmed cell death protein 1 (PD-1) ligand 1 (PD-L1). Targeting PD-1/PD-L1 alone has no effect in PDAC, highlighting the need for combination approaches. P2Y₁₂, an ADP receptor, is expressed by macrophages, and P2Y₁₂ antagonists promote phagocytosis, in turn, is linked to anti-tumor activity. Here, we tested the combined blockade of PD-1/PD-L1 and P2Y₁₂ on TAMs in pancreatic cancer. For this purpose, we set up co-cultures of pancreatic cancer cells and TAMs and treated them with inhibitor BMS-1, which blocks PD-1/PD-L1 interaction, cemiplimab to block PD-1, and ticagrelor to block P2Y₁₂. We observed that the co-treatment of ticagrelor and cemiplimab promoted TAM phagocytic ability and inhibited the TAM-induced growth and migration of cancer cells. The combination of ticagrelor and cemiplimab inhibited TGF-β1 release from TAMs and Smad2 phosphorylation in cancer cells. Our data suggest that co-treatment of ticagrelor and cemiplimab in TAMs inhibits pancreatic cancer cell growth and migration by suppressing the TGF-β1/Smad2 signaling pathway, providing an emerging strategy aimed at re-educating or depleting TAMs to enhance the efficacy of immunotherapy in pancreatic cancer.

Antidepressant use during pregnancy is increasingly common, with selective serotonin reuptake inhibitors (SSRIs) widely prescribed for maternal depression. However, growing evidence links prenatal SSRI exposure to adverse outcomes, including impaired placental functions, disrupted fetal development, and long-term neurobehavioral risks. Monoamines such as serotonin, dopamine, and norepinephrine are critical regulators of placental vascular tone, fetal programming, and neurodevelopment, making them highly susceptible to pharmacological disruption. Here, we investigated the effects of prenatal paroxetine on monoamine regulation, metabolite profiles, and fetoplacental hemodynamics in a pregnant rat model. Paroxetine was administered orally at two doses, 15 mg/kg (n = 10) or 50 mg/kg (n = 7) and compared to controls (n = 6). Gene expression of monoamine-related transporters and enzymes was quantified in placenta and fetal brain by qRT-PCR. Placental and fetal brain metabolomes were assessed via LC-MS, and Doppler ultrasound was used to evaluate uterine and fetal vascular parameters. At 15 mg/kg, paroxetine reduced fetal (2.03 ± 1.10 g vs. 2.27 ± 0.92 g) and placental weights (0.35 ± 0.08 g vs. 0.46 ± 0.05 g), downregulated placental expression of serotonin, dopamine, and norepinephrine transporters, disrupted tryptophan metabolism, and increased vascular resistance in umbilical arteries (2.10 ± 0.21 vs. 1.85 ± 0.05). Surprisingly, the 50 mg/kg dose attenuated many of these effects, suggesting non-linear pharmacological response, potentially due to transporter saturation and/or receptor desensitization. Importantly, gene expression and hemodynamic effects were consistent across sexes. These findings provide novel mechanistic insights into the impact of SSRIs on placental function and fetal development, underscoring the complexity of their pharmacokinetics and pharmacodynamics during pregnancy and emphasizing the need for careful dose consideration during pregnancy.