Clinical and Experimental Pharmacology and Physiology最新文献

Mycobacterium abscessus is a multi-drug resistant pathogen presenting significant treatment challenges. This study evaluated MRX-5, an oral prodrug of the leucyl-tRNA synthetase inhibitor MRX-6038, for its efficacy against M. abscessus both in vitro and in vivo. Stability testing of MRX-5 was conducted using liquid chromatography–tandem mass spectrometry in Middlebrook 7H9 broth at 35°C. Following this, the minimum inhibitory concentrations of MRX-5 were determined against two reference strains and 17 clinical isolates of M. abscessus. In the in vivo experiments, the pharmacokinetic properties of MRX-5 were assessed first, followed by efficacy testing conducted in a neutropenic BALB/c mouse model of M. abscessus lung infection. Remarkably, the conversion of MRX-5 to MRX-6038 in liquid broth was complete within 72 h, and MRX-5 demonstrated reduced potency compared to MRX-6038 in vitro. In vivo, MRX-5 was efficiently converted to MRX-6038, achieving an oral bioavailability of 83.95% and significant lung distribution. In the mouse model of pulmonary M. abscessus infection, MRX-5 effectively reduced bacterial load and exhibited antimicrobial activity comparable to that of linezolid. In conclusion, MRX-5 exhibited favourable lung distribution and in vivo efficacy against M. abscessus, positioning it as a promising candidate for the oral treatment of M. abscessus infections.

Polypoid lesions of the gallbladder (PLG) represent localised protrusions of the gallbladder wall, which can be either benign or malignant. Although malignant PLG is relatively rare, its prognosis is adverse. Cholecystectomy is the most efficacious treatment for malignant PLG; however, its suitability varies among PLG patients, and its indications remain controversial. To offer guidance for clinical diagnosis and treatment of PLG, 461 patients were included and classified into three subgroups based on postoperative pathological results. Logistic regression analysis was employed to identify the risk factors for PLG (the number of lesions, gallbladder wall thickness, gallbladder stones, and clinical symptoms), malignant PLG (age, polyp size, colour Doppler blood flow signal, gallbladder volume, and cholecystitis), and adenomatous PLG (CA199, the number of lesions, and gallbladder wall thickness). Multivariate logistic regression analysis was employed to construct clinical prediction models for PLG (model A, containing the number of lesions, gallbladder wall thickness, gallbladder stones, and clinical symptoms), malignant PLG (model B, containing age, polyp size, CA199, and gallbladder volume), and adenomatous PLG (model C, containing CA199, the number of lesions, and gallbladder wall thickness). Subsequently, corresponding nomograms were developed. The AUC values of all models exceeded 0.7, indicating excellent predictive efficacy. Calibration curves and DCA curves affirmed the models' reliability and validity. In conclusion, the models derived from this study demonstrate significant predictive efficacy for PLG, malignant PLG, and adenomatous PLG, respectively. They are anticipated to offer guidance for the diagnosis of PLG and provide a reliable foundation for subsequent treatment strategies.

Retinopathy of prematurity is characterised by abnormal retinal neovascularization in response to hypoxia stress. Prolyl 4-hydroxylase domain protein 3 (PHD3) is a well-known molecular oxygen sensor. However, the role that PHD3 plays in retinopathy of prematurity remains unclear. In this work, a mouse model of oxygen-induced retinopathy (OIR) was used for in vivo studies. Compared with the mice in room air, OIR mice showed sprouting of retinal neovascularization and increased level of PHD3. It was further found that PHD3 overexpression weakened OIR-induced retinal neovascularization and promoted cell apoptosis in the retina, indicating a mitigative effect on retinopathy. More importantly, OIR-induced upregulation of hypoxia inducible factor-1 alpha (HIF-1α) and vascular endothelial growth factor (VEGFA) was offset by PHD3 overexpression. In in vitro experiments, mouse retinal microvascular endothelial cells (MRMECs) were cultured under hypoxic conditions. The functions of endothelial cells including cell proliferation, cell migration, and tube formation ability were suppressed by PHD3, suggesting an anti-angiogenesis effect of PHD3. In line with in vivo experiments, the expression of HIF-1α and VEGFA levels declined in endothelial cells when PHD3 was overexpressed. Taken together, PHD3 alleviates retinopathy of prematurity through anti-angiogenesis, and the core mechanism may involve cell apoptosis of retina endothelial cell and HIF-1α–VEGFA axis. These findings provide exciting new insights into the pathogenesis of retinopathy of prematurity, and could offer new treatment directions.

Isoferulic acid (IA), a derivative of cinnamic acid, is derived from Danshen and exhibits anticancer properties by disrupting cancer cell activities. However, its role in pancreatic cancer, the “king of cancer”, was unknown. In this study, pancreatic cancer cells were subjected to treatment with IA (6.25, 12.5, 25 μM), and nude mice injected with pancreatic cancer cells were received IA at doses of 7.5 mg/kg/day or 30 mg/kg/day by oral administration. CCK8, Annexin V-FITC/propidium iodide (PI) double staining and TUNEL assay were conducted to evaluate the cell viability and apoptosis. Hoechst staining and comet assay was employed to measure DNA damage. Mitochondrial membrane potential (MMP) analysis was carried out to explain the mitochondrial damage. EdU and wound healing assay were performed for cell proliferation and migration detection. Immunofluorescence and western blot were used to explore the mechanism. We found that IA reduced cell viability and induced apoptosis, as evidenced by an increase in Annexin V-FITC⁺PI⁻ and Annexin V-FITC⁺PI⁺ cell populations, brighter TUNEL and Hoechst staining, and more percentage of tail DNA. Furthermore, IA decreased MMP and changed levels of apoptosis-related proteins. The cell proliferation and migration were inhibited by IA treatment. Mechanically, IA downregulated the phosphorylation of IĸBα and inhibited p65 nuclear translocation, consequently suppressing NF-κB pathway. In general, IA suppressed the cell proliferation and migration, and caused apoptosis of pancreatic cancer cells in a mitochondria-dependent manner through blocking NF-κB signalling pathway, indicating that IA may be a potential therapeutic strategy for pancreatic cancer.

Osteoporosis is mainly caused by an imbalance in osteoclast and osteoblast regulation, resulting in an imbalance in bone homeostasis. Ginsenoside Rg3 (Rg3) has been reported to have a therapeutic effect on alleviating osteoporosis. Nonetheless, the underlying mechanisms have not been completely elucidated. Herein, the molecular mechanism of Rg3 alleviation in osteoporosis was further explored. An in vitro model was established utilising the receptor activator of nuclear factor-kappaB ligand (RANKL) to induce osteoclast differentiation of RAW264.7 cells. RNA-sequencing results showed that karyopherin subunit alpha 2 (KPNA2) is one of the significantly differentially expressed genes regulated by Rg3 in RANKL-induced RAW264.7 cells. Basic experiments further suggested that KPNA2 is up-regulated in a time-dependent manner in the RANKL-induced RAW264.7 cells, while Rg3 treatment reduced its expression in a dose- and time-dependent manner. Knockdown of KPNA2 inhibited osteoclast formation and the expression of related molecules, including those in the nuclear factor kappa-B (NF-κB) pathway. The NF-κB inhibitor, JSH-23, partially abolished the impact of KPNA2 overexpression on osteoclast formation, indicating KPNA2 activates NF-κB. Furthermore, KPNA2 overexpression partially abolished the inhibitory impact of Rg3 on osteoclast formation, indicating that KPNA2 is a target of Rg3. These results suggest that KPNA2 plays a role in how Rg3 influences on osteoclast differentiation and osteoporosis through the NF-κB pathway.

Evidence regarding the relationship between free triiodothyronine (FT3) and low-density lipoprotein cholesterol (LDL-C) remains limited. This study aimed to evaluate the association between FT3 and LDL-C levels in patients with type 2 diabetes mellitus (T2DM) who exhibit normal thyroid function. Between June 2022 and October 2023, a total of 3011 inpatients with T2DM and euthyroid status were continuously and non-selectively recruited from a Chinese hospital. The average age of the included individuals was 56.92 ± 12.56 years, with 1430 (47.49%) males. The mean FT3 concentration was 4.35 ± 0.56 pmol/L. A logistic regression model was applied to analyse the relationship between the FT3 and LDL-C levels, while smooth curve fitting was employed to investigate potential nonlinear associations between these variables. This study demonstrated a positive correlation (0.05 [95% CI: 0.02–0.07; p = 0.0018]) and nonlinear relationship (p = 0.0014) between FT3 and LDL-C levels in Chinese patients with diabetes. Specifically, when FT3 was below 4.28 pmol/L, LDL-C levels increased alongside rising FT3 concentration. However, when FT3 reached or exceeded 4.28 pmol/L, LDL-C levels plateaued and tended to stabilise. These findings suggest that maintaining FT3 within the range of 2.76 to 4.28 pmol/L may be most beneficial for mitigating the progression of cardiovascular disease in patients with T2DM. Our research is important for identifying the optimal FT3 range to delay the progression of cardiovascular disease in patients with T2DM. These findings provide valuable insights to guide clinicians in preventing and managing cardiovascular disease in this population.

BRAF inhibitors (BRAFi) represent a cornerstone in melanoma therapy due to their high efficacy. However, the emergence of resistance causes a significant challenge to their clinical utility. This study aims to investigate the potential of diclofenac as a sensitizer for BRAFi therapy in melanoma and to elucidate its underlying mechanism. BRAFi-acquired resistant melanoma cell lines SK-MEL-5R and A375R were established and treated with diclofenac in combination with BRAFi PLX4032. Cell viability was assessed using the MTT assay, cell proliferation was determined by crystal violet staining, cell apoptosis was evaluated by flow cytometry, and intracellular ROS levels were measured using the DCFH-DA probe-labeled and flow cytometry. Mitochondrial membrane potential was assessed by JC-1 staining and flow cytometry, and protein expression levels were detected by western blotting. Our results demonstrated that diclofenac significantly augmented the cytotoxicity of PLX4032 and enhanced its ability to induce apoptosis in SK-MEL-5R and A375R cells. Diclofenac treatment led to the release of intracellular reactive oxygen species (ROS), consequently reducing transmembrane potential, promoting mitochondrial apoptosis, and activating the ROS downstream p38/p53 signaling pathway. Pretreatment with N-acetylcysteine significantly reversed the sensitizing effect of diclofenac on PLX4032 in SK-MEL-5R cells. These findings suggested that diclofenac sensitized BRAFi-resistant melanoma cells to BRAFi by increasing ROS release and activating p38/p53 signaling pathway. Diclofenac might serve as a promising adjunct therapy to overcome BRAFi resistance in melanoma treatment.